Neutrons, the energy of which exceeds some arbitrary level, usually around one million electron volts.
Electrically neutral elementary particles found in all atomic nuclei except light hydrogen; the mass is equal to that of the proton and electron combined and they are unstable when isolated from the nucleus, undergoing beta decay. Slow, thermal, epithermal, and fast neutrons refer to the energy levels with which the neutrons are ejected from heavier nuclei during their decay.
Radiotherapy using high-energy (megavolt or higher) ionizing radiation. Types of radiation include gamma rays, produced by a radioisotope within a teletherapy unit; x-rays, electrons, protons, alpha particles (helium ions) and heavy charged ions, produced by particle acceleration; and neutrons and pi-mesons (pions), produced as secondary particles following bombardment of a target with a primary particle.
Nuclear reaction in which the nucleus of a heavy atom such as uranium or plutonium is split into two approximately equal parts by a neutron, charged particle, or photon.
The study of the characteristics, behavior, and internal structures of the atomic nucleus and its interactions with other nuclei. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The scattering of NEUTRONS by matter, especially crystals, with accompanying variation in intensity due to interference effects. It is useful in CRYSTALLOGRAPHY and POWDER DIFFRACTION.
Rate of energy dissipation along the path of charged particles. In radiobiology and health physics, exposure is measured in kiloelectron volts per micrometer of tissue (keV/micrometer T).
A technique for the treatment of neoplasms in which an isotope is introduced into target cells followed by irradiation with thermal neutrons.
The ratio of radiation dosages required to produce identical change based on a formula comparing other types of radiation with that of gamma or roentgen rays.
Unstable isotopes of cobalt that decay or disintegrate emitting radiation. Co atoms with atomic weights of 54-64, except 59, are radioactive cobalt isotopes.
A technique for the treatment of neoplasms, especially gliomas and melanomas in which boron-10, an isotope, is introduced into the target cells followed by irradiation with thermal neutrons.
The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.
Activation analysis in which the specimen is bombarded with neutrons. Identification is made by measuring the resulting radioisotopes. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Neutron generator (HIRRAC) and dosimetry study. (1/56)

Dosimetry studies have been made for neutrons from a neutron generator at Hiroshima University (HIRRAC) which is designed for radiobiological research. Neutrons in an energy range from 0.07 to 2.7 MeV are available for biological irradiations. The produced neutron energies were measured and evaluated by a 3He-gas proportional counter. Energy spread was made certain to be small enough for radiobiological studies. Dose evaluations were performed by two different methods, namely use of tissue equivalent paired ionization chambers and activation of method with indium foils. Moreover, energy deposition spectra in small targets of tissue equivalent materials, so-called lineal energy spectrum, were also measured and are discussed. Specifications for biological irradiation are presented in terms of monoenergetic beam conditions, dose rates and deposited energy spectra.  (+info)

Dose estimations of fast neutrons from a nuclear reactor by micronuclear yields in onion seedlings. (2/56)

Irradiations of onion seedlings with fission neutrons from bare, Pb-moderated, and Fe-moderated 252Cf sources induced micronuclei in the root-tip cells at similar rates. The rate per cGy averaged for the three sources, , was 19 times higher than rate induced by 60Co gamma-rays. When neutron doses, Dn, were estimated from frequencies of micronuclei induced in onion seedlings after exposure to neutron-gamma mixed radiation from a 1 W nuclear reactor, using the reciprocal of as conversion factor, resulting Dn values agreed within 10% with doses measured with paired ionizing chambers. This excellent agreement was achieved by the high sensitivity of the onion system to fast neutrons relative to gamma-rays and the high contribution of fast neutrons to the total dose of mixed radiation in the reactor's field.  (+info)

Neutron energy-dependent initial DNA damage and chromosomal exchange. (3/56)

This study was undertaken to investigate the biological effect of monoenergetic neutrons on human lymphocyte DNA and chromosomes. Monoenergetic neutrons of 2.3, 1.0, 0.79, 0.57, 0.37 and 0.186 MeV were generated, and 252Cf neutrons and 60Co gamma-rays were also used for comparison. Biological effect was evaluated two ways. The RBE values with the comet assay were estimated as 6.3 and 5.4 at 0.37 MeV and 0.57 MeV relative to that of 60Co gamma-rays, and chromosome aberration rates were also observed in these different levels of monoenergetic neutrons. The yield of chromosome aberrations per unit dose was high at lower neutron energies with a gradual decline with 0.186 MeV neutron energy. The RBE was increased to 10.7 at 0.57 MeV from 3.9 at 252Cf neutrons and reached 16.4 as the highest RBE at 0.37 MeV, but the value decreased to 11.2 at 0.186 MeV. The response patterns of initial DNA damage and chromosome exchange were quite similar to that of LET. These results show that the intensity of DNA damage and chromosomal exchange is LET dependent. RBE of low energy neutrons is higher than that of fission neutrons. Low energy neutrons containing Hiroshima atomic bomb radiation may have created a significantly higher incidence of biological effect in atomic bomb survivors.  (+info)

Neutron-energy-dependent cell survival and oncogenic transformation. (4/56)

Both cell lethality and neoplastic transformation were assessed for C3H10T1/2 cells exposed to neutrons with energies from 0.040 to 13.7 MeV. Monoenergetic neutrons with energies from 0.23 to 13.7 MeV and two neutron energy spectra with average energies of 0.040 and 0.070 MeV were produced with a Van de Graaff accelerator at the Radiological Research Accelerator Facility (RARAF) in the Center for Radiological Research of Columbia University. For determination of relative biological effectiveness (RBE), cells were exposed to 250 kVp X rays. With exposures to 250 kVp X rays, both cell survival and radiation-induced oncogenic transformation were curvilinear. Irradiation of cells with neutrons at all energies resulted in linear responses as a function of dose for both biological endpoints. Results indicate a complex relationship between RBEm and neutron energy. For both survival and transformation, RBEm was greatest for cells exposed to 0.35 MeV neutrons. RBEm was significantly less at energies above or below 0.35 MeV. These results are consistent with microdosimetric expectation. These results are also compatible with current assessments of neutron radiation weighting factors for radiation protection purposes. Based on calculations of dose-averaged LET, 0.35 MeV neutrons have the greatest LET and therefore would be expected to be more biologically effective than neutrons of greater or lesser energies.  (+info)

Uncertainties of DS86 and prospects for residual radioactivity measurement. (5/56)

Residual radioactivity data of 152Eu, 60Co and 36Cl have been accumulated and it has been revealed in the thermal neutron region that a systematic discrepancy exists between the measured data and activation calculation based on the DS86 neutrons in Hiroshima. Recently 63Ni produced in copper samples by the fast neutron reaction 63Cu(n,p)63Ni has been of interest for evaluation of fast neutrons. Reevaluation of atomic-bomb neutrons and prospects based on residual activity measurements have been discussed.  (+info)

Positive selection of mutants with deletions of the gal-chl region of the Salmonella chromosome as a screening procedure for mutagens that cause deletions. (6/56)

We have developed a convenient and specific positive selection for long deletions through the gal region of the chromosomes of Salmonella typhimurium and Escherichia coli. Through simultaneous selection for mutations in the two closely linked genes, gal and chlA, a variety of deletions of varying length, some extending through as much as 1 min of the chromosome, could be readily obtained. Many of these deletions resulted in the loss of a gene, which we named dhb, concerned with the ability of the bacterium to synthesize the iron chelating agent enterobactin. The selection was adapted for the screening of mutagens for their ability to generate long deletions in the bacterial deoxyribonucleic acid. Forty agents were screened for this capability. Nitrous acid, previously reported to be an efficient mutagen for this purpose, increased the frequency of deletion mutations 50-fold in our system. Three others, nitrogen mustard, mitomycin C, and fast neutrons, were shown to increase the frequency of long deletions between five- and eightfold. The remainder were found to be incapable of generating these deletions.  (+info)

First results of a randomized clinical trial of fast neutrons compared with X or gamma rays in treatment of advanced tumours of the head and neck. Report to the Medical Research Council. (7/56)

Results of the first randomized clinical trial to compare the effects of fast neutrons and those of x or gamma rays (photons) in treating patients with advanced tumours of the head and neck are reported. In 37 out of 52 patients treated with neutrons and 16 out of 50 treated with photons the local tumour completely regressed; the tumour later recurred in nine of the 16 photon patients but in none of the 37 neutron patients. The advantages to the neutron-treated patients were seen in tumours of well and poorly differentiated histology and in each site. Complications after treatment did not differ significantly between the groups. Despite these substantial differences in local control of the tumour there were no significant differences in mortality between the series. A detailed study of the effective doses and the response of tumours and normal tissue in each series indicated that the improved results from neutron therapy were due to differences in the biological quality of the beam and not to the rather higher average effective dose in the neutron series. To assess the long-term effects of neutron treatment patients in earlier stages of disease and with smaller tumours should be included in the next phase of the trial.  (+info)

Dose and dose-rate effects of X rays and fission neutrons on lymphocyte apoptosis in p53(+/+) and p53(-/-) mice. (8/56)

Following the exposure of mice to X rays or fission neutrons, the frequency (F) of apoptosis was measured after 4 h, and the weight loss or lymphocyte content loss in the thymus and spleen was measured after 24 h. In p53(+/+) mice, F increased linearly with the dose (D (Gy)) and the induced rate per Gy of F (detected by TUNEL staining) was 0.05 and 0.23 for X rays and fission neutrons, respectively. Therefore, the RBE of fission neutrons was 4.6 for apoptosis induction. This indicates that radiation-induced apoptosis is mostly due to double strand breaks (DSBs) in DNA because we previously obtained almost the same RBE value of fission neutrons for the induction of crossover mutations in Drosophila melanogaster, which arise from the recombinational repair of DSBs. In p53(+/+) mice, decreases in the organ weight and the lymphocyte content were observed for the thymus and the spleen 24 h after X-irradiation. These atrophic changes in the thymus and the spleen quantitatively corresponded to the total apoptotic cell deaths occurring in them. However, in p53(-/-) mice, no vigorous apoptosis was induced after X-irradiation, and hyperplastic changes in the weight and the lymphocyte content appeared in the thymus and the spleen 24 h after X-irradiation. In p53(+/+) mice, there was no difference in the induced rate per Gy of reduction in the surviving fraction of lymphocytes between acute (0.4 Gy/min) and chronic (3 mGy/min) gamma-irradiations. Namely, radiation-induced apoptosis in lymphocytes is a dose-rate independent event.  (+info)

books.google.com.auhttps://books.google.com.au/books/about/Collision_cross_sections_of_carbon_and_h.html?id=QozmAAAAMAAJ&utm_source=gb-gplus-shareCollision cross sections of carbon and hydrogen for fast neutrons ...
M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission ...
Fast neutron reactors use fast neutrons to cause fission in their fuel. They do not have a neutron moderator, and use less-moderating coolants. Maintaining a chain reaction requires the fuel to be more highly enriched in fissile material (about 20% or more) due to the relatively lower probability of fission versus capture by U-238. Fast reactors have the potential to produce less transuranic waste because all actinides are fissionable with fast neutrons, but they are more difficult to build and more expensive to operate. Overall, fast reactors are less common than thermal reactors in most applications. Some early power stations were fast reactors, as are some Russian naval propulsion units. Construction of prototypes is continuing (see fast breeder or generation IV reactors ...
The practical methods for generating fast-neutron beams for cancer radiotherapy are compared (DT versus D on Be). A general effort is made to compare and contrast the interactions and depth-dose patterns for gamma ray beams with those for the NRL fast-neutron beam of app. 14-MeV average energy (35-MeV D+ on Be). Typical instrumentation for dosimetry and monitoring are described, and the procedure for absolute dose calibration of non-tissue-equivalent ionization chambers is outlined, based on application of the Bragg-Gray relation. The buildup of the dose by the secondary proton field in TE first few millimeters of tissue (which gives rise to skin-sparing in radiotherapy) has been measured in TE plastic, and the compromise of skin sparing by superposition of various materials is also shown, along with restoration of skin sparing by interposing lead foils to filter out the recoil protons. Narrow-broad-beam attenuation coefficients for 60 Co gamma rays vs the NRL neutron beam are shown for a variety of
Neutron crystallography compliments x-ray crystallography in its ability to precisely locate hydrogen and light atoms in various materials. This information is important for biological applications (for example, monitoring protein dynamics), and material research and security applications (for example, explosives detection, etc.). However, the detectors available for scattered neutron radiation are still inadequate. The ideal detector would provide fast response, high spatial resolution, high neutron efficiency, low gamma sensitivity, and large detection area at reasonable cost. This project will develop a detector, based on a finely-structured plastic scintillator coupled to a state-of-the-art digital readout, that meets the above requirements The structure of the scintillators body will enhance light channeling to the digital optical detector, promoting very high spatial resolution. The scintillator will be loaded with neutron sensitive elements, such as B and Gd. In Phase I, a 5 x 5 cm2 ...
Fast neutrons passive dosimetry with Si - diodes. Since several years, Si-diodes have been used for the fast neutron dosimetry in the case of high level exposure, accidental enclosed. This work describes the results of tests performed with the diodes of a new production, presents their characteristics and the analysis of the possibilities of their use. The diodes of two different sensitivities were irradiated at the SILENE reactor (irsn Valduc). We studied: the reproducibility of reading and the influence of its repetition, the homogeneity of the lot of diodes studied, the evolution of the signal with the time after irradiation, the influence of the thermal treatment on this evolution, the response of two types of diodes to the neutrons of SILENE reactor in two configurations, the detection threshold expressed in tissue kerma. The results obtained are presented, analysed and discussed. The principal knowledge is formulated in the conclusion ...
The seasonal variation of neutron emissions from Mars in different spectral intervals measured by the HEND neutron detector for the entire Martian year are analyzed. Based on these data, the spatial variations of the neutron emissions from the planet are globally mapped as a function of season, and the dynamics of seasonal variation of neutron fluxes with different energies is analyzed in detail. No differences were found between seasonal regimes of neutron fluxes in different energy ranges in the southern hemisphere of Mars, while the regime of fast neutrons (with higher energies) during the northern winter strongly differs from that during the southern winter. In winter (L s = 270°-330°), the fast neutron fluxes are noticeably reduced in the northern hemisphere (along with the consecutive thickening of the seasonal cap of solid carbon dioxide). This provides evidence of a temporary increase in the water content in the effective layer of neutron generation. According to the obtained ...
Lead or lead-bismuth eutectic in fast neutron reactors are capable of higher temperature operation. They are transparent to neutrons, aiding efficiency, and since they do not react with water the heat exchanger interface is safer. They do not burn when exposed to air. However, they are corrosive of fuel cladding and steels, which originally limited temperatures to 550°C. With todays materials 650°C can be reached, and in future 700°C is in sight, using oxide dispersion-strengthened steels. A problem is that Pb-Bi yields toxic polonium (Po-210) activation products. Pb-Bi melts at a relatively low 125°C (hence eutectic) and boils at 1670°C, Pb melts at 327°C and boils at 1737°C but is very much more abundant and cheaper to produce than bismuth, hence is envisaged for large-scale use in the future, though freezing must be prevented. The development of nuclear power based on Pb-Bi cooled fast neutron reactors is likely to be limited to a total of 50-100 GWe, basically for small reactors in ...
Accelerated ions: protons, deuterons and alpha particles with maximum energy 13MeV/amu and fast neutrons irradiation with maximum fluxes 1011n/cm2* ...
Background Soybean is subjected to genetic manipulation by breeding, mutation, and transgenic approaches to produce value-added quality traits. Among those genetic approaches, mutagenesis through fast...
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International Scholarly Research Notices is a peer-reviewed, Open Access journal covering a wide range of subjects in science, technology, and medicine. The journals Editorial Board as well as its Table of Contents are divided into 108 subject areas that are covered within the journals scope.
Physically, this is the speed of the neutron. A 2 MeV neutron is traveling at about 45 million miles/hr. Neutrons moving this fast dont often linger to induce fission in other atoms. Statistically they are likely to leave the reactor core before an interaction occurs. For this reason it is desirable to slow them down. Neutrons are slowed by allowing them to bounce off lighter atoms and transfer their kinetic energy to the atoms. This process is called moderation, and slows the neutrons down to what is called thermal energy, .025 eV, or about 4900 miles/hr. Depending on the mass of the moderating material, it may take from 10-2500 impacts to reduce the speed of a fast neutron from fission to thermal equillibrium ...
E170 Terminology Relating to Radiation Measurements and Dosimetry. E265 Test Method for Measuring Reaction Rates and Fast-Neutron Fluences by Radioactivation of Sulfur-32. E693 Practice for Characterizing Neutron Exposures in Iron and Low Alloy Steels in Terms of Displacements Per Atom (DPA). E720 Guide for Selection and Use of Neutron Sensors for Determining Neutron Spectra Employed in Radiation-Hardness Testing of Electronics. E721 Guide for Determining Neutron Energy Spectra from Neutron Sensors for Radiation-Hardness Testing of Electronics. E844 Guide for Sensor Set Design and Irradiation for Reactor Surveillance. E944 Guide for Application of Neutron Spectrum Adjustment Methods in Reactor Surveillance. ...
2. Adam Same,Vincent Battaglia,Hong-Yue Tang and Jae Wan Park: In situ neutron radiography analysis of graphite/NCA lithium-ion battery during overcharge. J Appl Electrochem 42,1-9 (2012) 3. Yung-Tsi Bolon, William J. Haun, Wayne W. Xu, David Grant, Minviluz G. Stacey, Rex T. Nelson, Daniel J. Gerhardt, Jeffrey A. Jeddeloh, Gary Stacey, Gary J. Muehlbauer, James H. Orf, Seth L. Naeve, Robert M. Stupar, and Carroll P. Vance: Phenotypic and Genomic Analyses of a Fast Neutron Mutant Population Resource in Soybean,. Plant Physiology, 156, 240-253 (2011). 4. Hong-Yue Tang, Anthony Santamaria, Jae Wan Park, Changwoo Lee, Woonbong Hwang: Quantification of water in hydrophobic and hydrophilic flow channels subjected to gas purging via neutron imaging,. Journal of Power Sources 196, 9373- 9381 (2011) 5. J.T. Cremer, D. L. Williams, M. J. Fuller, C. K. Gary, M. A. Piestrup, R. H. Pantell, J. Feinstein, R. G. Flocchini, M. Boussoufi, H. P. Egbert, M. D. Kloh, and R. B. Walker: Periodic magnetic field as a ...
tex]^2_1D+^3_2He \rightarrow ^1_1p + ^4_2He[/tex] is in theory a desirable reaction for fusion energy because (i) it does not produce neutrons and (ii) much useful energy can be gotten electromagnetically (decelerating the fast protons) instead of thermally (so the efficency limits of heat engines do not apply). As far as I know this is very unrealistic, because (i) D-He3 fusion requires much higher energies than for example D-T (which is already very hot), and (ii) D-D fusion will occur under in the same regime and produces lots of fast neturons, which defeats the benefit of D+He3 not producing fast neutrons. So myself I dont see what the big deal is about ...
Stress caused by the increased salinity of irrigated fields impairs plant growth and is one of the major constraints that limits crop productivity in many important agricultural areas. As a contribution to solving such agronomic problems, we have carried out a large-scale screening for Arabidopsis thaliana mutants induced on different genetic backgrounds by EMS treatment, fast neutron bombardment, or T-DNA insertions. From the 675,500 seeds we screened, 17 mutant lines were isolated, all but one of which yielded 25-70% germination levels on 250 mm NaCl medium, a condition in which their ancestor ecotypes are unable to germinate. Monogenic recessive inheritance of NaCl-tolerant germination was displayed with incomplete penetrance by all the selected mutants, which fell into five complementation groups. These were named SALOBREÑO (SAÑ) and mapped relative to polymorphic microsatellites, the map positions of three of them suggesting that they are novel genes. Strains carrying mutations in the ...
Dr. Leung and Tak Pui Lou have designed a very compact D-D or D-T fast neutron generator in a capsule configuration that is less than 8 mm in diameter and only 2 cm long. This generator is portable and is ideal for insertion into an oil well logging drill. A larger variation of this invention with ...
Used nuclear fuel has long been reprocessed to extract fissile materials for recycling and to reduce the volume of high-level wastes. New reprocessing technologies are being developed to be deployed in conjunction with fast neutron reactors which will burn all long-lived actinides.
Used nuclear fuel has long been reprocessed to extract fissile materials for recycling and to reduce the volume of high-level wastes. New reprocessing technologies are being developed to be deployed in conjunction with fast neutron reactors which will burn all long-lived actinides.
The ITER Hot Cell Complex supports the operation, maintenance and decommissioning of the ITER Tokamak. The complex consists of three buildings: the Hot Cell Building, the Radwaste and the Personnel Access Control Buildings. Together they provide a secure environment for the processing, repair or refurbishment, testing, and disposal of ITER components that have become activated by neutron exposure. Although no radioactive products are produced by the fusion reaction itself, energetic neutrons interacting with the walls of the vacuum vessel will activate these materials over time. Also, materials can become contaminated by beryllium and tungsten dust, and tritium. Heavy refurbishment operations within the Hot Cell Facility will be performed by remote handling systems capable of handling components up to the size of a school bus. The Hot Cell Facility will also house remote handling equipment for simulation and rehearsal of operations. In addition, the Hot Cell Facility will perform the removal of
Die Universität zu Köln ist eine Exzellenzuniversität mit dem klassischen Fächerspektrum einer Volluniversität. Als eine der größen Hochschulen Europas arbeitet sie in Forschung und Lehre auch international auf höchstem Niveau.
We call running the plant harder a power uprate. The time-dependence of the embrittlement is mostly due to the integrated neutron fluence, so you would think with higher power level in the core, the fluence would go up and the embrittlement would occur faster. But - the fluence at the vessel wall also depends upon the design of the core (what enrichment and burnup each individual fuel assembly has). It turns out in many cases that modern core designs result in lower fluence than that assumed in the original analyses. So, with calculation of the actual embrittlment during the fuel cycles that have actually been run, it may be that the predicted vessel life is longer, even accounting for the power uprate. Finally, this concern was addressed in detail by the NRC before they licensed the plant to begin with and again before they amend the license to permit the uprate. Look on the nrc website (nrc dot gov) for a document called RS-001, this is the NRC guidance on evaluating power uprates ...
Radiotherapy is the use of radiation to treat conditions such as cancer. The most common technique exposes tumors to high energy photons (x-rays) and/or electrons while sparing normal tissues. Other uses are to prepare a patient for organ transplantation by suppressing immune response and to calm muscle twitches. The therapy can be delivered from the outside (external beam radiotherapy), by radioactive implants placed in the body (brachytherapy), or during surgery (interoperative). Other types of radiotherapy such as proton therapy and neutron therapy -- available at very limited centers -- have their own distinct advantages and disadvantages.
Purpose: In proton therapy, it could be desirable to measure out-of-field fast neutron doses at critical locations near and outside the patient body. Methods: The working principle of a novel clinical neutron dose monitor is verified by MCNPX simulation. The device is based on a small PE moderator of just 5.5cm side length for easy handling covered with a thermal neutron suppression layer. In the simulation, a polystyrene phantom is bombarded with a standard proton beam. The secondary thermal neutron flux produced inside the moderator by the impinging fast neutrons from the treatment volume is estimated by pairs of α-Al2O3:C (TLD500) chips which are evaluated offline after the treatment either by TL or OSL methods. The first chip is wrapped with 0.5mm natural Gadolinium foil converting the thermal neutrons to gammas via (n,γ) reaction. The second chip is wrapped with a dummy material. The chip centers have a distance of 2cm from each other. Results: The simulation shows that the difference of ...
Objective: Undesired neutron contamination imposed to patients during treatment is among the main factors increasing the risk of secondary cancer in radiotherapy. This additional undesirable dose is due to neutron contamination production in high-energy accelerators. In this study, neutron contamination is investigated in the presence of wedge and block in 15 MV photon fields of Siemens Primus linear accelerator. Materials and Methods: Neutron production by 30°, 45°, and 60° wedges and cerrobend block was investigated. Measurements were conducted in a 10 cm × 10 cm field at the source to -surface distance of 100 cm at 0.5, 2, 3, and 4 cm depths of a 30 cm × 30 cm × 30 cm Perspex phantom using the CR-39 passive film detectors. Chemical etching was performed using sodium hydroxide solution with 6.25 M concentration as the etchant at 85°C for 3 h. Results: The neutron dosimetry results reveal that the presence of wedge and block increases the neutron contamination. However, the 45° wedge is ...
Neutron flux measurements have been made (1)2 of low-level neutron sources present in several types of neutron-producing facilities. The flux levels or distribution of thermal, epithermal, and fast neutrons have been measured in radioisotope sources, spent fuel element gamma irradiation facilities, and electron linear accelerators. Sensitivities greater than 1 neutron per sq cm per sec have been achieved for thermal neutrons. Neutron flux measurements may be made by several methods (2). Foil activation (3) is a convenient and simple technique. The foils containing materials of known cross-section are exposed to the neutrons, and the flux determinations are made by measurement of the induced activities in the irradiated foils. This technique is widely used for measuring neutron fluxes and spectra in nuclear reactors and critical facilities where the neutron fluxes are large (106 to 1014 neutrons per sq cm per sec). To measure neutron fluxes of smaller magnitude, such as those found in isotope ...
The nested neutron spectrometer (NNS) is a tool used for neutron spectroscopy. The NNS is used to measure the energy spectrum of neutrons in a neutron field. This type of detector is used in both research facilities (for characterization of neutron fields) and workplaces, where neutron radiation maybe encountered, for radiation protection purposes. Due to the difficulty associated with the detection of neutrons, the NNS is one of the few pieces of equipment capable of accurately determining the characteristics of a neutron field. The NNS operates under the same principle as a Bonner sphere neutron spectrometer. The sensitive part of the spectrometer is the Helium-3 proportional counter, which detects neutrons through the reaction 3He(n,p)3H. This particular reaction has a significant cross-section only at thermal neutron energies. In order for a higher energy neutrons to be detected their energies must be decreased, or moderated. To slow down neutrons at higher energies the NNS uses different ...
For future generation nuclear power plants, fission or fusion based, the need for improved fuels and structural materials is crucial. The use of nuclear power is associated with several major problems: the handling of the long-lived radioactive waste, the limited resources of U-235 and the safety and integrity of the structural materials. These issues are addressed by the development of advanced reactor types, GenIV reactors, in which Am and Pu are transmuted, thereby decreasing the effective half-life of the waste, and at the same time fissile fuel is generated from natural uranium (U-238). This is achieved by the use of non-moderated (fast) neutrons in the fission process, and so called fast reactors have been used on an experimental scale for decades. A fundamental challenge connected to the use of fast neutrons is the damage induced in various parts of the reactor. Well known effects are hardening, embrittlement and swelling of the fuel and of internal parts such as cladding, spacers, tubes, ...
Jun 09, 2011· Does the absorption cross section to scattering cross section ratio of an isotope vary with neutron energy or stay constant? I have heard that cross sections in general are inversely proportional to velocity (eg the fission cross section of U235 is about 1000 times higher for thermal neutrons than fast neutrons) which would suggest the answer is yes.. ...
1:,br> #Thermal neutrons have a kinetic energy of about 0.025eV #Fast neutrons are braked with elastic collisions with particles with the same size as the neutrons. A moderator also needs to have a low cross-section for absorbing neutrons. #A moderator is a material that brakes the neutrons, for instance H,sub>2,/sub>O, D,sub>2,/sub>O, C, Be. A neutron absorbent catches the neutrons and reacts with the neutron. Good absorbants are borium and gadolinium. #From the nuclide carte we can see that ,sup>3,/sup>He has a high cross-section for the n,p-reaction. #The reaction ,sup>3,/sup>He+n arrow ,sup>3,/sup>H,sup>+,/sup>+,sup>1,/sup>H(+,sup>2,/sup>e,sup>-,/sup>). The charged particles from the reaction creates more ionisations when they travel towards the anode and the cathode, this gives a electric signal. #The Q-value from the reaction is 764 keV, the reaction is exothermic. #,sup>3,/sup>H,sup>+,/sup> and ,sup>1,/sup>H,sup>+,/sup> is created. #The two products in the reaction recives opposing ...
1:,br> #Thermal neutrons have a kinetic energy of about 0.025eV #Fast neutrons are braked with elastic collisions with particles with the same size as the neutrons. A moderator also needs to have a low cross-section for absorbing neutrons. #A moderator is a material that brakes the neutrons, for instance H,sub>2,/sub>O, D,sub>2,/sub>O, C, Be. A neutron absorbent catches the neutrons and reacts with the neutron. Good absorbants are borium and gadolinium. #From the nuclide carte we can see that ,sup>3,/sup>He has a high cross-section for the n,p-reaction. #The reaction ,sup>3,/sup>He+n arrow ,sup>3,/sup>H,sup>+,/sup>+,sup>1,/sup>H(+,sup>2,/sup>e,sup>-,/sup>). The charged particles from the reaction creates more ionisations when they travel towards the anode and the cathode, this gives a electric signal. #The Q-value from the reaction is 764 keV, the reaction is exothermic. #,sup>3,/sup>H,sup>+,/sup> and ,sup>1,/sup>H,sup>+,/sup> is created. #The two products in the reaction recives opposing ...
Control rods are used in nuclear reactors to control the fission rate of uranium and plutonium. They are composed of chemical elements such as boron, silver, indium and cadmium that are capable of absorbing many neutrons without themselves fissioning. Because these elements have different capture cross sections for neutrons of varying energies, the composition of the control rods must be designed for the reactors neutron spectrum. Boiling water reactors (BWR), pressurized water reactors (PWR) and heavy water reactors (HWR) operate with thermal neutrons, while breeder reactors operate with fast neutrons. Control rods are usually used in control rod assemblies (typically 20 rods for a commercial PWR assembly) and inserted into guide tubes within a fuel element. A control rod is removed from or inserted into the central core of a nuclear reactor in order to increase or decrease the neutron flux, which describes the number of neutrons that split further uranium atoms. This in turn affects the ...
I am wondering if I expose plants to Neutron radiation and carefully burn them afterwords.at 500 deg C is this safe and more importantly is it Legal??...
ENGLISH SUMMARY : Background: Success rates in the treatment of salivary gland malignancies are associated with completeness of surgical resection with or without postoperative radiotherapy. For patients with unresectable tumours, radiotherapy is an option to attempt to gain local control and improve survival. Different modalities of radiotherapy are available and fast neutrons represent a form of radiotherapy effective in controlling locally advanced salivary gland malignancies. We report on 22 patients treated for locally advanced parotid gland malignancies at iThemba Laboratory for Accelerator Based Sciences via a tertiary institution in Cape Town, South Africa. Methods: Records of patients with unresectable parotid gland malignancies treated with neutron radiotherapy at a tertiary institution between January 1991 and December 2012 were reviewed retrospectively. Twenty-two patients were eligible for statistical analysis. Results: Complete, partial and no response rates were 64%, 14% and 22%, ...
P. Andrew Karam, an adjunct professor of physics at the Rochester Institute of Technology, explains. Nuclear reactors generate energy through fission, the process by which an atomic nucleus splits into two or more smaller nuclei. During fission, a small amount of mass is converted into energy, which can be used to power a generator to create electricity. In order to harness this energy, a controlled chain reaction is required for fission to take place. When a uranium nucleus in a reactor splits, it produces two or more neutrons that can then be absorbed by other nuclei, causing them to undergo fission as well. More neutrons are released in turn and continuous fission is achieved. Neutrons produced by fission have high energies and move extremely quickly. These so-called fast neutrons do not cause fission as efficiently as slower-moving ones so they are slowed down in most reactors by the process of moderation. A liquid or gas moderator, commonly water or helium, cools the neutrons to optimum ...
Well start with neutron radiation first, because its really the simplest. First of all, neutron radiation is the only one that impacts the nucleus of the atom. The other three cause damage through ionization of the atoms electrons. To understand neutron radiation, imagine a pool table set for the start of a game. 15 balls are in the middle of the table, with the cue ball set for the break. The cue ball is a free neutron. When the neutron hits the nucleus, one of three things might happen. First, if the cue ball doesnt have enough energy, or hits at the wrong angle, it caroms off, barely disturbing the pack of balls. Second, if the ball has too much energy, it slams through the pack. breaking it up. This is fission, and results in fission products, more free neutrons, and energy. Third, if the ball has just the right amount of energy, it just makes it to the pack and joins in, becoming another neutron in the nucleus. Here is where our analogy breaks down, because many times, when a nucleus ...
1.. V. V. Orlov et al., The State and Prospects for the Development of Atomic Electric Power Stations with Fast Neutron Reactors. Report at the Symposium of the Council of Economic Mutual Aid [in Russian], Obninsk (1967). ...
Highly enriched uranium (HEU) has a 20% or higher concentration of 235U. The fissile uranium in nuclear weapon primaries usually contains 85% or more of 235U known as weapons-grade, though theoretically for an implosion design, a minimum of 20% could be sufficient (called weapon(s)-usable) although it would require hundreds of kilograms of material and would not be practical to design;[4][5] even lower enrichment is hypothetically possible, but as the enrichment percentage decreases the critical mass for unmoderated fast neutrons rapidly increases, with for example, an infinite mass of 5.4% 235U being required.[4] For criticality experiments, enrichment of uranium to over 97% has been accomplished.[6]. The very first uranium bomb, Little Boy, dropped by the United States on Hiroshima in 1945, used 64 kilograms of 80% enriched uranium. Wrapping the weapons fissile core in a neutron reflector (which is standard on all nuclear explosives) can dramatically reduce the critical mass. Because the ...
The nature of the interaction between a neutron and an atomic nucleus depends upon the characteristics of the nucleus involved. Consequently some information concerning nuclear structure can be derived from studies of the scattering of neutrons by nuclei. The experimental observations can be compared with the theoretical predictions and may support the theory or suggest a different approach to the theoretical problem. One method of studying neutron scattering is to observe in a cloud chamber the tracks produced by nuclei recoiling from collisions with the neutrons. From measurements of the lengths of the recoil tracks and their angles with respect to the incident neutron direction, the distribution of the scattered neutrons in angle and energy may be deduced ...
Since the end of the cold war, the need for operating weapons production facilities has faded. Criticality Safety Limits and controls supporting production modes in these facilities became outdated and furthermore lacked the procedure based rigor dictated by present day requirements. In the past, in many instances, the formalism of present day criticality safety evaluations was not applied. Some of the safety evaluations amounted to a paragraph in a notebook with no safety basis and questionable arguments with respect to double contingency criteria. When material stabilization, clean out, and deactivation activities commenced, large numbers of these older criticality safety evaluations were uncovered with limits and controls backed up by tenuous arguments. A dilemma developed: on the one hand, cleanup activities were placed on very aggressive schedules; on the other hand, a highly structured approach to limits development was required and applied to the cleanup operations. Some creative approaches were
http://www.conservativerefocus.com/blog5.php/2011/03/15/fukushima-mark-1-reactor-design-caused-engineers-to-resign-from-ge-in-protest-thirty-five-years-ago. ABC News. By MATTHEW MOSK. Thirty-five years ago, Dale G. Bridenbaugh and two of his colleagues at General Electric resigned from their jobs after becoming increasingly convinced that the nuclear reactor design they were reviewing - the Mark 1 - was so flawed it could lead to a devastating accident.. Questions persisted for decades about the ability of the Mark 1 to handle the immense pressures that would result if the reactor lost cooling power, and today that design is being put to the ultimate test in Japan. Five of the six reactors at the Fukushima Daiichi plant, which has been wracked since Fridays earthquake with explosions and radiation leaks, are Mark 1s.. The problems we identified in 1975 were that, in doing the design of the containment, they did not take into account the dynamic loads that could be experienced with a loss of ...
Principal Investigator:ICHIHASHI Masamitsu, Project Period (FY):1986 - 1987, Research Category:Grant-in-Aid for General Scientific Research (C), Research Field:Dermatology
This report describes the experiments performed to measure the energy spectrum of neutrons released in certain atomic-weapons tests in Operation Greenhouse. The measurements were made of two types 1 the time-of-flight measurements designed to establish the fission neutron spectrum down to about 3 Mev energy, and 2 the so-called Tenex Temperature-Neutron Experiment measurements designed to obtain the velocity distribution of neutrons produced by the deuterium-tritium fusion reactions.
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(Phys.org)-Stuart Kauffman, from the University of Calgary, and several of his colleagues have recently published a paper on the Arxiv server titled Quantum Criticality at the Origins of Life. The idea of a quantum criticality, ...
A novel spectrometer was developed and used to measure the cross section for the (n, α) reaction at the Institute for Physics and Power Engineering. Direct measurements of the alpha particles yielded from isotopically enriched solid targets of 50Cr, 52Cr, and 53Cr; 54Fe and 57Fe; 60Ni; 64Zn; and 47Ti were carried out in the neutron energy range from 4.0 to 7.2 MeV. For some of the isotopes, the (n, α) reaction cross sections for neutron energies below 14 MeV were measured for the first time. The result of the comparison of new experimental data with the evaluated data from ENDF/B-VII, JENDL-4.0, JEFF-3.2, ROSFOND-2010, and BROND-3 libraries and with the experimental data of other authors is presented.. ...
The program computes the neutron spectrum in a uniform lattice made up of cylindrical rods, cladding, and surrounding moderator. The LASER is based on modified versions of the slowing-down program MUFT and the thermalization transport theory program THERMOS. The program performs a burnup calculation for the lattice. The spatial distribution of burnup within the fuel rods is explicitly calculated. This calculation accounts for the variation of the neutron flux in space and energy during each time step. A buckling and a boron poison search (criticality search) are provided as options ...
Since 2003, when spontaneous activity in cortical slices was first found to follow scale-free statistical distributions in size and duration, increasing experimental evidences and theoretical models have been reported in the literature supporting the emergence of evidence of scale invariance in the cortex. Although strongly debated, such results refer to many different in vitro and in vivo preparations (awake monkeys, anesthetized rats and cats, in vitro slices and dissociated cultures), suggesting that power law distributions and scale free correlations are a very general and robust feature of cortical activity that has been conserved across species as specific substrate for information storage, transmission and processing. Equally important is that the features reminiscent of scale invariance and criticality are observed at scale spanning from the level of interacting arrays of neurons all the way up to correlations across the entire brain. Moreover, the existing relationship between features of
The materials inside a fusion reactor must withstand one of the most extreme environments in science, with temperatures in the thousands of degrees Celsius and a constant bombardment of neutron radiation and deuterium and tritium, isotopes of hydrogen, from the volatile plasma at th... ...
The materials inside a fusion reactor must withstand one of the most extreme environments in science, with temperatures in the thousands of degrees Celsius and a constant bombardment of neutron radiation and deuterium and tritium, isotopes of hydrogen, from the volatile plasma at th... ...
The codes WIMSD/4 and BORGES--part of the MTR-PC code package--have been applied to prepare the microscopic cross-section library for the main elements of miniature neutron source reactor (MNSR) core for six neutron energy groups. The generated libra
No single molecular change is uniquely necessary to cause neuropathic changes in primary afferent excitability; multiple different changes are sufficient.
Using fast neutrons, the mercury isotope 198Hg, which composes 9.97% of natural mercury, can be converted by splitting off a ... When other mercury isotopes are irradiated with slow neutrons, they also undergo neutron capture, but either convert into each ... "Transmutation of Mercury by Fast Neutrons". Physical Review. 60 (7): 473-479. Bibcode:1941PhRv...60..473S. doi:10.1103/PhysRev. ... Irradiation by slow neutrons would transmute these isotopes into 186Re and 188Re, which have half-lives of 3 days and 17 hours ...
Another alternative to fast-neutron breeders are thermal-neutron breeder reactors that use uranium-233 bred from thorium as ... "Fast Neutron Reactors , FBR - World Nuclear Association". www.world-nuclear.org. Retrieved 7 October 2018. "Prototype fast ... Spent MOX fuel cannot generally be recycled for use in thermal-neutron reactors. This issue does not affect fast-neutron ... As opposed to light water thermal-neutron reactors, which use uranium-235 (0.7% of all natural uranium), fast-neutron breeder ...
There are currently seven experimental fast neutron reactors running globally, in India, Japan, Russia and China. Fast neutron ... The word 'fast' in fast breeder thus refers to the speed of the neutrons in the reactor's core. The higher the energy the ... Fast Breeder Reactors, are called fast because they have no moderator slowing down the neutrons (light water, heavy water or ... It is most useful as part of a nuclear fuel cycle utilizing fast-neutron reactors since reprocessed uranium and reactor-grade ...
"Fast neutron reactor." 25 Jul. 1961. US patent 2993850 Fellow of the American Nuclear Society, 1962. Outstanding Teacher Award ... Methods and cross sections for calculating the fast effect. Nuc. Sci. Eng., 7:217, 1960. Thumm, W., D.E. Tilly, S.J. Inglis and ...
"Fast Neutron Reactors". World Nuclear Association. Retrieved 11 March 2012. Harold Feiveson; et al. (2011). "Managing nuclear ... The plutonium-uranium ratio in the ash may even approximate the composition needed for fast neutron reactor fuel. Further ... The lanthanides have large neutron cross sections and hence they would poison a neutron driven nuclear reaction. To date the ... though many of these materials would require a fast breeder reactor in order to be burned efficiently. In a thermal neutron ...
Fast Neutron Physics Group (FNPG). "Fast Neutron Generator". PINSTECH Institute's Media Research Cell (Note: For more ... slow-neutron-capture-process). It is designed and planned to do fast neutron activation for elements such as oxygen and ... This fusion experimental devices has capability to capture the low neutron flux on the order of 105 to 108 neutrons per cm2 per ... The neutron generator was bought by the PAEC from Texas A&M Nuclear Science Center. The facility is capable of producing mono- ...
Vogel, F. S.; Pickering, J. E. (1956). "Demyelinization Induced in the Brains of Monkeys by Means of Fast Neutrons". The ... Pickering, J. E.; Brown, D. (1959). "Nuclear propulsion: cataractogenic effects from fast neutrons". Texas State Journal of ... cataractogenic effects from fast neutrons The effects from massive doses of high dose rate gamma radiation on monkeys Biologic ... Effects of Gamma Radiation on the Retina DEMYELINIZATION INDUCED IN THE BRAINS OF MONKEYS BY MEANS OF FAST NEUTRONS ...
Taylor, H. L., Lönsjö, O., & Bonner, T. W. (1955). Nonelastic scattering cross sections for fast neutrons. Physical Review. 100 ... He invented a neutron-counter-ratio technique for the determination of neutron emission thresholds. He also invented a sphere- ... GB 862434). Romain, F. S., Bonner, T. W., Bramblett, R. L., & Hanna, J. (1962). Low-Energy Neutrons from the Reaction Be 9 (α, ... He did important work in the development of high-pressure cloud chambers for the study of neutrons produced by accelerators. ...
This so-called fast-neutron embrittlement is a complex function of many factors including the neutron fluence, the neutron ... fast-neutron (E > 1 MeV) radiation-induced embrittlement of the RPV steel could lead to a compromise of the vessel integrity, ... In the case of neutron detectors, high efficiency is gained through the use of scintillating materials rich in hydrogen that ... Additional factors may also come into play, such as the neutron fluence-rate, whose effects have not been fully investigated. ...
Fast neutron therapy. *Neutron capture therapy of cancer. *Particle beam. *Radiation therapist ... This technique is well established and is generally quick and reliable. The worry is that some high-dose treatments may be ... Although this moist desquamation is uncomfortable, recovery is usually quick. Skin reactions tend to be worse in areas where ... This schedule, known as a concomitant boost regimen or hyperfractionation, is used on tumors that regenerate more quickly when ...
Fast-neutron. *Neutron capture therapy of cancer. *Targeted alpha-particle. *Proton-beam ... Time-of-flight PET makes use of very fast gamma-ray detectors and data processing system which can more precisely decide the ... The uptake of the drug, the tissues in which it concentrates, and its eventual elimination, can be monitored far more quickly ... Navalpakkam, Bharath K.; Braun, Harald; Kuwert, Torsten; Quick, Harald H. (2013). "Magnetic Resonance-Based Attenuation ...
Fast-neutron. *Neutron capture therapy of cancer. *Targeted alpha-particle. *Proton-beam ... "5 MeV" in prompt neutron radiation (99.36% of total), "7 MeV" in delayed neutron energy (0.64%) and "13 MeV" in beta decay and ... For nuclear explosive devices where the fallout is not attainable or would be misleading, neutron activation analysis is often ... They transfer their energy quickly to the surrounding weapon materials, which rapidly become heated" ...
"Attenuation of fast neutrons: neutron moderation and diffusion". Kaye and Laby Tables of Physical and Chemical Constants. ... It is an effective neutron moderator and was used in James Chadwick's 1932 experiments to identify the neutron. Paraffin wax is ... Manufacture of boiled leather armor and books Neutron radiation shielding Wax baths for occupational and physical therapies, ...
Fast neutrons are not easily captured by nuclei; they must be slowed (slow neutrons), generally by collision with the nuclei of ... If these neutrons are captured by another unstable nucleus, they can fission as well, leading to a chain reaction. The average ... When a neutron is captured by a suitable nucleus, fission may occur immediately, or the nucleus may persist in an unstable ... A fusor can also produce controlled fusion and is a useful neutron source. However, both of these devices operate at a net ...
"NISHINA Memorial Foundation 2008 - Induced β-Activity of Uranium by Fast Neutrons" (PDF). Nishina Memorial Foundation. March ... "NISHINA Memorial Foundation 2008 - Induced β-Activity of Uranium by Fast Neutrons" (PDF). Nishina Memorial Foundation. March ... showed that they had produced neptunium-237 by exposing triuranium octoxide to fast neutrons for more than 50 hours. 1940 - ... "Fission Products of Uranium produced by Fast Neutrons". Nature. 146 (3688): 24. Bibcode:1940Natur.146...24N. doi:10.1038/ ...
Crocker Radiation Laboratory The Treatment of Cancer with Fast Neutrons 1 Neutron therapy and specific ionization EO Lawrence-A ... "The Treatment of Cancer with Fast Neutrons 1." Radiology 39.5: 608-620. Stone, R. S. (1948). Neutron therapy and specific ... Abersold, Paul C. (October 1939). The production of a beam of fast neutrons. Phys. Rev. 56: 714-727. Stone, Robert S., John H. ... September 1940). "A Preliminary Report on the Use of Fast Neutrons in the Treatment of Malignant Disease 1." Radiology 35.3: ...
These are fast-neutron reactors. There's others: a resurgence of hybrid solutions of fusion fission where the fusion would ... We're looking at reactors that have a high-energy neutron spectrum that can actually allow you to burn down the long-lived ... impart not only energy, but again creates high-energy neutrons that can burn down the long-lived actinides. ... Some of the ...
"Twin" scintillation fast neutron detector. Rev. Sci. Instr. 27(10) (June 25): 858-859 Miller, C.E., and L.D. Marinelli. 1956. ... "Twin" scintillation fast neutron detector. Rev. Sci. Instr. 27(10): 858-859 Gustafson, P.F., L. D. Marinelli, and E. A. ...
... scintillator method for the dosimetry and spectrometry of fast neutrons to the measurement of cosmic neutron background. In ... Twin scintillation fast neutron detector. Review of Scientific Instruments, 27/110:858-859 L.D. Marinelli (Supplement by H.A. ... In 1956, he developed the twin scintilltor method for dosimetry and spectrometry of fast neutrons and its application to the ... Apparatus for counting fast neutrons in the presence of gamma rays. Patent #2, 795, 703A. Washington, D.C.: U.S. Patent and ...
For fast neutrons it is on the order of 1 barn. At thermal energy levels, about 5 of 6 neutron absorptions result in fission ... Uranium-238 is fissionable by fast neutrons, but cannot support a chain reaction because inelastic scattering reduces neutron ... Uranium-232 is a rare example of an even-even isotope that is fissile with both thermal and fast neutrons. Uranium-233 is a ... The fission-to-capture ratio improves for faster neutrons. Uranium-236 is an isotope of uranium that is neither fissile with ...
"Activation of Fast Neutron Detectors by Cyclotron and by Fission Neutrons". Technical Report CF-863 Metallurgical Lab ... Szilard, L.; Bernstein, S.; Feld, B.; Ashkin, J. (1948). "Inelastic Scattering of Fast Neutrons by Fe, Pb, and Bi". Physical ... The group's main task was to estimate the rate at which neutrons would diffuse through the explosive core of the bomb during ... It is The Calculation of Critical Masses Including the Effects of the Distribution of Neutron Energies, by Feynman, R.P.; ...
Some early fast neutron reactors used mercury. For certain applications the stems of automotive poppet valves may be hollow and ... The use of CO2 greatly extends tool life, and on most materials allows the operation to run faster. This is considered a very ... Helium has a low tendency to absorb neutrons and become radioactive. Carbon dioxide is used in Magnox and AGR reactors. Sulfur ... Heavy water is a neutron moderator used in some nuclear reactors; it also has a secondary function as their coolant. Light ...
Fast Neutron Generator- An experimental neutron generator. The PINSTECH four research directorates and each directorate is ... Atomic and Nuclear Radiation Group Fast Neutron Diffraction Group (FNDG) Electronic and Magnetic Materials Group (EMMG) Nuclear ... Collaboration Vacuum Technology Laboratory Vibration Analysis It was founded as Fast Neutron Physics Group by Dr. Samar ... a reprocessing plant and another experimental neutron source based on: PARR-I Reactor-Utilize Low-Enriched Uranium (LEU) PARR- ...
An alternative neutron detector uses fast neutrons that enter the ground and are moderated by it; the flux of thermal neutrons ... These sources emit fast neutrons with an energy of 14.1 million electron volts (MeV) from the neutron tube and 0-13 MeV from ... Sheehy, Christian B. (1 June 2003). "Fast Neutron Technology Used for Explosive Detection". National Defense. Retrieved 7 March ... Neutrons can also be generated using a portable particle accelerator (a sealed neutron tube) that promotes the fusion of ...
Fast-neutron. *Neutron capture therapy of cancer. *Targeted alpha-particle. *Proton-beam ... Two or three: Electrons, ions, protons and neutrons can be distinguished by the sign and value of their charge so that they ... Astrophysical plasmas are also observed in Accretion disks around stars or compact objects like white dwarfs, neutron stars, or ... Maxwellian: Collisions usually lead to a Maxwellian velocity distribution of all gas particles, with very few relatively fast ...
In solid-fuel reactors, on restart the 135Xe in the fuel absorbs neutrons, followed by a sudden jump in reactivity as the 135Xe ... Additions of uranium and plutonium to the salt during operation were quick and uneventful, and recovery of uranium by ... The 233U capture-to-fission ratio in a typical MSR neutron spectrum is an example of basic data that was improved. The effect ... Since this was an engineering test, the large, expensive breeding blanket of thorium salt was omitted in favor of neutron ...
These can be used in thermal-neutron reactors, whereas a mixture of curium isotopes is only suitable for fast breeder reactors ... α-particles to produce curium with the release of a neutron: Pu. 94. 239. +. He. 2. 4. ⟶. Cm. 96. 242. +. n. 0. 1. {\ ... Further neutron capture followed by β−-decay produces the 241Am isotope of americium which further converts into 242Cm: Pu. 94 ... A much higher neutron flux is used for the irradiation that results in a different reaction chain and formation of 244Cm:[7] ...
MSR using fast neutrons cannot use graphite anyway to avoid moderation. Thermal MSRs have lower breeding ratios than fast- ... Fuel rod fabrication is not required (replaced with fuel salt synthesis). Some designs are compatible with the fast neutron ... Neutron damage to solid moderator materials can limit the core lifetime of an MSR that uses moderated thermal neutrons. For ... A possibly good neutron economy makes the MSR attractive for the neutron poor thorium fuel cycle Little development compared to ...
1940: "The effects of fast neutrons on the chromosomes of Tradescantia". Proc. Natl. Acad. Sci. U. S. A. 26:567-575. 1948: With ...
Kanner the first demonstration of fission by fast neutrons and thorium and uranium. His thesis was on the interaction of fast ... 50 Issue 6, p. 106-8 "Study of uranium and thorium fission produced by fast neutrons of nearly homogeneous energy. Phys. Rev. ... New Mexico continuing his work with fast neutrons. In 1946 he joined the University of Wisconsin-Madison, where he remained for ... In a paper with John A. Wheeler he reported the discovery of spin-orbit coupling in neutron scattering. He worked at the ...
"Sodium and Potassium Quick Health Facts". Retrieved 7 November 2011.. *^ "Dietary Reference Intakes: Water, Potassium, Sodium, ... Caesium-137 has a very low rate of neutron capture and cannot be feasibly disposed of in this way, but must be allowed to decay ... All the alkali metals have odd atomic numbers; hence, their isotopes must be either odd-odd (both proton and neutron number are ... Furthermore, it is very useful as a heat-exchange liquid in fast breeder nuclear reactors due to its low melting point, ...
Experimental treatments include targeted therapy, gamma knife radiosurgery,[45] boron neutron capture therapy and gene therapy. ... thus promoting faster transmission of electrical signals and also providing for general maintenance of the environment ... and in a confined space such as the intracranial cavity this quickly becomes problematic because the mass invades the space of ...
Helium, heavy elements, and neutrons. "Triple tracks" in a CR-39 plastic radiation detector claimed as evidence for neutron ... Its discovery 30 years earlier had also been unexpected, though it was quickly replicated and explained within the existing ... Fleischmann and Pons reported a neutron flux of 4,000 neutrons per second, as well as detection of tritium. The classical ... Jones, however, was measuring neutron flux, which was not of commercial interest.[28][clarification needed] To avoid future ...
The high thermal neutron absorbance of boron also has the secondary effect of biasing the neutron spectrum to higher energies, ... fast combustion reactions. Advantages of SHS include higher purity of ceramic products, increased sinterability, and shorter ... neutron-absorption cross-section of 759 barns, and stoichiometric boron content. Boron acts as a "burnable" neutron absorber ... In addition to this deleterious effect of integrating a neutron absorber on the surface of a fuel pellet, boron coatings have ...
More recently, driven by advances in experimental technique (such as neutron diffraction) and available computational power, ... but it is much faster and cheaper. The solution is vaporized and its absorption spectrum is measured in the visible and ...
Lovesey, S. W. (1984). Theory of Neutron Scattering from Condensed Matter; Volume 1: Neutron Scattering. Oxford: Clarendon ... longer-lasting and faster-charging batteries, sensors to diagnose diseases[18]. Potential applications of graphene ... Lovesey, S. W. (1984). Theory of Neutron Scattering from Condensed Matter; Volume 2: Condensed Matter. Oxford: Clarendon Press ... Squires, G.L. (1996). Introduction to the Theory of Thermal Neutron Scattering (2nd ed.). Mineola, New York: Dover Publications ...
Silver however tarnishes quickly and the silver sulfide that is produced is poorly conductive, degrading connector performance ... such as for neutron flux counters in nuclear reactors. ...
Heavy water is employed in nuclear reactors because it is a weaker neutron absorber. This allows for the use of less enriched ... Apple's Power Mac G5 was the first mainstream desktop computer to have water cooling as standard (although only on its fastest ... Quick-release couplings sized for optimized flow. *Connection guiding system and compensation of misalignment during connection ... Especially useful in supercomputers or Data Centers as maintenance of the racks is quick and easy. After disassembly of the ...
This results in the rest of the villains quickly turning their attention to him and bringing him down. Upon the discovery of ... Neutron - Presumably killed when Luthor's teleporter self-destructed. Plasmus - Presumably killed when Luthor's teleporter self ... They are interrupted by another Parademon patrol who are quickly defeated after some of them do away with General Immortus and ... Luthor leaves last, revealing that he used Heatmonger (of the Aryan Brigade), Thunder and Lightning, Plasmus, Neutron and Warp ...
For this reason they were popularly called island universes, but this term quickly fell into disuse, as the word universe ... neutron stars, and black holes. Eventually, as a result of gravitational relaxation, all stars will either fall into central ... They are thought to have an increased star formation rate around 30 times faster than the Milky Way.[75][76] ... If so, these huge stars would have quickly consumed their supply of fuel and became supernovae, releasing heavy elements into ...
The scattered probe is either photons (grazing-incidence small-angle X-ray scattering, GISAXS) or neutrons (grazing-incidence ... With the advent of nanoscience other applications evolved quickly, first in hard matter such as the characterization of quantum ... As a particular consequence of the DWBA, the refraction of x-rays or neutrons has to be always taken into account in the case ... At neutron research facilities, GISANS is increasingly used, typically on small-angle (SANS) instruments or on reflectometers. ...
Typical particles produced in such collisions are neutrons and charged mesons such as positive or negative pions and kaons. ... The caustic sodium hydroxide dissolves the plastic at a faster rate along the path of the ionized plastic. The net result is a ... Carbon-14 (5730 years): 14N(n, p)14C (neutron activation) ... and neutrons.[64] All of the produced particles stay within ... which for cosmic rays are gamma rays emitted as they travel faster than the speed of light in their medium, the atmosphere.[79] ...
Commercially available optical flowmeters are capable of measuring flow from 0.1 m/s to faster than 100 m/s (1000:1 turn down ... The faster the flow the higher the frequency and the voltage output. ...
Herudover er 7Li, Be og F blandt de få nuklider, der har så lavt neutron-tværsnit, at de ikke forgifter fissionsreaktionerne ... Det er det mindst fyldige af alle de grundstoffer, der har fast form ved rumtemperatur; det næst-letteste faste grundstof ( ... såvel som som fast fusionsbrændstof til brug inde i hydrogenbomber i form af lithiumdeuterid. USA blev verdens ledende ... der har neutron-tværsnit lave nok til at kunne fungere som centrale bestanddele i forædler i brændstof til smeltesaltreaktorer. ...
HEU is also used in fast neutron reactors, whose cores require about 20% or more of fissile material, as well as in naval ... It also contains the undesirable isotope uranium-236, which undergoes neutron capture, wasting neutrons (and requiring higher U ... Because the core was surrounded by a good neutron reflector, at explosion it comprised almost 2.5 critical masses. Neutron ... but as the enrichment percentage decreases the critical mass for unmoderated fast neutrons rapidly increases, with for example ...
This process is relatively fast (and faster for the helium than for the hydrogen), and is known as recombination.[23] At the ... Protons (hydrogen ions) and neutrons begin to combine into atomic nuclei in the process of nuclear fusion. Free neutrons ... Protons and neutrons are bound into primordial atomic nuclei, hydrogen and helium-4. Small amounts of deuterium, helium-3, and ... The quark-gluon plasma that composes the universe cools until hadrons, including baryons such as protons and neutrons, can form ...
Microalgae can grow 20 or 30 times faster than traditional food crops, and has no need to compete for arable land. Since ... chemical variants of an element that contain different neutrons. Microalgae can effectively incorporate isotopes of carbon (13C ...
subsequent consideration of strong force-mediated neutron-neutron repulsion raised the estimate to approximately 1.5 M. ☉ to ... Lower-mass black holes are expected to evaporate even faster; for example, a black hole of mass 1 TeV/c2 would take less than ... were shown to be rapidly rotating neutron stars.[36] Until that time, neutron stars, like black holes, were regarded as just ... Shapiro, S. L.; Teukolsky, S. A. (1983). Black holes, white dwarfs, and neutron stars: the physics of compact objects. John ...
He was given the title "Coordinator of Rapid Rupture", which specifically referred to the propagation of a fast neutron chain ... His work predicted many later finds, which include the neutron, meson and neutron star.[42] ... invited Oppenheimer to take over work on fast neutron calculations, a task that Oppenheimer threw himself into with full vigor ... This was followed by a paper co-written with one of his students, George Volkoff, "On Massive Neutron Cores",[50] in which they ...
With the development of fast digital computers, approximate solutions for more complicated molecules became possible and are ... Spectroscopy does not generally refer to diffraction studies where particles such as neutrons, electrons, or high energy X-rays ...
These sources of neutrons only produce 14. C at a rate of 1 x 10−4 atoms per gram per second, which is not enough to have a ... 2 in water increases with lower temperatures, glacial periods would have led to the faster absorption of atmospheric CO. 2 by ... which produces neutrons. However, experiments in which wood samples have been irradiated with neutrons indicate that the effect ... Even at an altitude of 3 km, the neutron flux is only 3% of the value in the stratosphere where most 14. C is created; at sea ...
... is quite electropositive, and it reacts slowly with cold water and quite quickly with hot water to form ytterbium(III ... by neutron activation during the irradiation of ytterbium in nuclear reactors, has been used as a radiation source in portable ... Visible light waves oscillate faster than microwaves, and therefore optical clocks can be more precise than caesium atomic ... Ytterbium dissolves slowly in water, but quickly in acids, liberating hydrogen gas.[8] ...
thermal neutron fission) *^ Effluent Releases from Nuclear Power Plants and Fuel-Cycle Facilities. National Academies Press (US ... The levels were expected to drop relatively quickly[22] ... This isotope of iodine has 78 neutrons in its nucleus, while ... The low-cost availability of 131I, in turn, is due to the relative ease of creating 131I by neutron bombardment of natural ... Most 131I production is from neutron irradiation of a natural tellurium target in a nuclear reactor. Irradiation of natural ...
The s-process is a slow neutron capture of lighter elements inside pulsating red giant stars.[48] Germanium has been detected ... Circuits utilizing the properties of Si-SiGe junctions can be much faster than those using silicon alone.[68] Silicon-germanium ... The reflectivity has advantages over silicon in neutron and high energy X-ray applications.[75] Crystals of high purity ... "Optimization of Germanium for Neutron Diffractometers". International Journal of Modern Physics E. 5 (1): 131-151. Bibcode: ...
As more air is pushed into the bubble, the buoyancy force grows quicker than the surface tension force. Thus, detachment occurs ... X rays and neutron scattering) at sub-micrometer scales, or microscopic ones. Considering the system as continuous, its bulk ... and the formation of foam faster than its breakdown. To create foam, work (W) is needed to increase the surface area (ΔA): ...
Neutron activation analysis indicates that much of the black-on-white pottery found at Mesa Verde was produced locally. ... the amount of goods imported by the mesa quickly declined, and Mesa Verde became isolated from the surrounding region.[33] For ... but also retained residential mobility so they could quickly relocate their dwellings in the event of resource depletion or ...
Geier, S.; Heber, U.; Heuser, C.; Classen, L.; o'Toole, S. J.; Edelmann, H. (2013). "The subdwarf B star SB 290 - A fast ... In this way they can quickly pass through blue giant, bright blue giant, blue supergiant, and yellow supergiant classes, until ... temperature and luminosity as they accumulate more and more helium until eventually they cannot sustain fusion and they quickly ...
... which fissions into two fast-moving lighter elements (fission products) and additional neutrons. Most of the energy released is ... Shortly after the discovery of the neutron by James Chadwick in 1932, Heisenberg submitted the first of three papers[45] on his ... A visual representation of an induced nuclear fission event where a slow-moving neutron is absorbed by the nucleus of a uranium ... On the detection and characteristics of the alkaline earth metals formed by irradiation of uranium with neutrons), ...
The number of neutrons varies according to the isotope: the stable isotopes have 8, 9, or 10 neutrons. Oxygen is a member of ... In this process, metal up to 60 cm (24 in) thick is first heated with a small oxy-acetylene flame and then quickly cut by a ... evaporate at a slightly faster rate than water molecules containing the 12% heavier oxygen-18, and this disparity increases at ... Decompression sickness occurs in divers who decompress too quickly after a dive, resulting in bubbles of inert gas, mostly ...
Fast neutron therapy utilizes high energy neutrons typically between 50 and 70 MeV to treat cancer. Most fast neutron therapy ... of fast neutrons is 4 times that of X-rays, meaning 1 rad of fast neutrons is equal to 4 rads of X-rays. The RBE of neutrons is ... Fast Neutron Radiotherapy: The University of Washington Experience and Potential Use of Concomitant Boost with Boron Neutron ... The UW Neutron system is referred to as the Clinical Neutron Therapy System (CNTS). The CNTS is typical of most neutron therapy ...
On average, more neutrons per fission are produced by fast neutrons than from thermal neutrons. This results in a larger ... A fast-neutron reactor (FNR) or simply a fast reactor is a category of nuclear reactor in which the fission chain reaction is ... With fast neutrons, the ratio between splitting and the capture of neutrons by plutonium and the minor actinides is often ... Such designs are known as fast breeder reactors.[citation needed] The main disadvantage of fast-neutron reactors is that to ...
... faster than some theories predict is possible - researchers may have to revise their models ... The fastest-spinning neutron star ever found has been discovered in a crowded star cluster near the centre of the Milky Way, a ... "even faster spinning neutron stars exist" but may be difficult to observe. ... Neutron stars form when a massive star explodes at the end of its life and leaves behind a super-dense, spinning ball of ...
Distributions of stopping power (LET) are given for four beams of fast neutrons, namely, neutrons of 14.6 MeV, neutrons ... neutrons of 3 MeV, and fast neutrons produced by bombardment of a {sup 235}U converter plate with thermal neutrons. The track ... are given for four beams of fast neutrons, namely, neutrons of 14.6 MeV, neutrons produced by bombarding a thick beryllium ... and fast neutrons produced by bombardment of a {sup 235}U converter plate with thermal neutrons. The track average LET is ...
... ISRN High Energy Physics ... M. Mahdavi and M. Shahbahrami, "Multiplication of fast neutrons source flux by using deuterium-helium-3 plasma," ISRN High ...
The measurements were performed at the neutron source of the Laue Langevin Institute (ILL) in Grenoble, France. The method can ... The high-speed neutron tomography developed at HZB generates a complete 3D image every 1.5 seconds and is thus seven times ... faster than before. The method facilitates a better understanding of water and nutrient uptake of crop plants. ... Since the Berlin neutron source of the HZB will cease operation in December, the fast imaging set-up will be integrated into ...
62 RADIOLOGY AND NUCLEAR MEDICINE; CARCINOMAS; NEUTRON THERAPY; MELANOMAS; USES; OSTEOSARCOMAS; ESOPHAGUS; FAST NEUTRONS; HEAD ... Fast neutron therapy has been applied to the treatment of cancer of the head and the neck, prostatic cancer, osteosarcoma, and ... abstractNote = {Fast neutron therapy has been applied to the treatment of cancer of the head and the neck, prostatic cancer, ... Treatment schedule for fast neutron therapy for esophageal cancer and lung cancer must be established, and moreover, it is ...
Guernsey, G.L.; Mott, G.R.; Nelson, B.K. & Roberts, A. CONSTRUCTION AND CALIBRATION OF A FAST NEUTRON SCINTILLATION ...
Graul E.H. (1980) Medical Considerations in Radiation Accidents and the Biologic Effect of Fast Neutrons in Hydrogen Bomb ... Medical Considerations in Radiation Accidents and the Biologic Effect of Fast Neutrons in Hydrogen Bomb Explosions. ...
... lower limit measured meson method mgm/cm2 neutron beam neutron energy interval neutron source neutrons having energies neutrons ... gb-gplus-shareCollision cross sections of carbon and hydrogen for fast neutrons. ... determined deuterium elastic electrical sensitivity energy range entered the sensitive experimental results fast neutrons final ... scattered nuclear nuclei number of coincidences number of neutrons obtained paraffin scatterers particle peak energy percent ...
... fast reactors, fast breeder reactors, the potential role of fast reactors in more fuller utilising the worlds uranium resource ... In China, R&D on fast neutron reactors started in 1964. A 65 MWt fast neutron reactor - the Chinese Experimental Fast Reactor ( ... Fast Neutron Reactors. (Updated December 2020). *Fast neutron reactors (FNRs) are a technological step beyond conventional ... fast neutron design, superseding its GT-MHR. The EM2 is a 500 MWt, 265 MWe helium-cooled fast-neutron HTR operating at 850°C to ...
... Author(s). Sitek, Mark Andrew ...
Conclusions from this picture of neutron penetration in sodium are made as to the types of transport calculations that can be ... A series of computer experiments was carried out to elucidate the penetration mechanisms of fast neutrons through thick layers ... Huang, L.Y. Mechanisms of fast neutron penetration in thick layers of sodium, report, January 1, 1975; United States. (digital. ... A series of computer experiments was carried out to elucidate the penetration mechanisms of fast neutrons through thick layers ...
Fast Neutron Imaging Scintillator with Low Sensitivity to Gamma Radiation. Printer-friendly version ... The ideal detector would provide fast response, high spatial resolution, high neutron efficiency, low gamma sensitivity, and ... The modified scintillator should find widespread in neutron radiography and neutron crystallography. The detector, along with ... The scintillator will be loaded with neutron sensitive elements, such as B and Gd. In Phase I, a 5 x 5 cm2 prototype sensor ...
Fast Neutron Yields Generated from Deuteron Break-up in Low Energy Reactions of Light Nuclei. Published: 0 ... The p+D reaction looks to be the most effective reaction for producing fast neutrons on low energy cyclotrons. ... Investigation of neutron production by break-up processes in light-nuclei reactions is described. The energy spectra of ... targets spectra are substantially harder having lower relative contribution of low-energy neutrons. ...
These bars were placed in series in front of a deuterium-deuterium neutron generator, which produced fast neutrons of ... Abstract: B15.00002 : Study of the Sensitivity of Plastic Scintillator to Fast Neutrons. 10:57 AM-11:09 AM ... in order to further understand the sensitivity of the plastic scintillators to fast neutrons. ... and numerous other aspects of the neutrons interactions. The rate of coincidental and correlated hits in multiple scintillator ...
Spallation Neutron Source * ARCS , Wide Angular-Range Chopper Spectrometer , BL-18 * BASIS , Backscattering Spectrometer , BL-2 ... Neutron Sciences Directorate. One Bethel Valley Rd. Oak Ridge, TN 37831. Office Phone: 865-574-0558. ... Inelastic neutron scattering (INS) and density functional theory (DFT) calculations showed that protons occupy bridging oxygen ... Confined interlayer water in tungsten oxide hydrates (WO3·nH2O) stabilizes the layered structure, which explains the fast ...
... made to compare and contrast the interactions and depth-dose patterns for gamma ray beams with those for the NRL fast-neutron ... Narrow-broad-beam attenuation coefficients for 60 Co gamma rays vs the NRL neutron beam are shown for a variety of materials, ... The practical methods for generating fast-neutron beams for cancer radiotherapy are compared (DT versus D on Be). A general ... Abstract : The practical methods for generating fast-neutron beams for cancer radiotherapy are compared (DT versus D on Be). A ...
Full functionality of the SoyBase site requires that JavaScript be enabled. Please turn on JavaScript in your browsers preferences. If you are using a selective JavaScript blocking plugin such as NoScript, add ...
FAQ - Bubble Fast Neutron Detector. If you have a question about this topic, the answer is probably in here!. ... a project about neutron. We dont have a lot of budget, so we cant. buy whatever we want. We need a bubble neutron detector, ... Use the New User Chat area Neutrons, Radiation, and Detection (& FAQs) FAQs: Neutron - Radiation Detection ... The neutron strikes producing tritium gas bubbles. Question: How hard is this "GEL" ? Someone have any idea? Is it really soft ...
We can readily., summarize the significant points that have been elicited from these experiments. 1. The response of this type of dosimeter is fundamentall
... November 30, 2017, Institut ... Spallation Neutron Source puts the squeeze on methane hydrate cages. March 15, 2012 (PhysOrg.com) -- Imagine a robot sent out ... Fast methane diffusion at the interface of two clathrate structures, Nature Communications (2017). DOI: 10.1038/s41467-017- ... Quasielastic neutron scattering experiments under a high pressure of 0.8 GPa were conducted at ILL to make these observations. ...
This paper has investigated the effect of nano-diamond powder on reflection of fast neutrons. I... ... Neutrons shielding is based on the fast neutrons reflection as prompt and delay gamma are produced by neutron capture [1]. The ... H.W. Schmitt, R.C. Block, R.L. Bailey, Total neutron cross section of 10B in the thermal neutron energy range, Volume17, June- ... Nano-diamond Powder Layer Effect on Fast Neutrons Reflection. Print Reference this ...
... we present the nuclear excitation functions of the fast neutron-induced reactions 52Cr(n,p)52V, 52Cr(n,α)49Ti, 52Cr(n,2n)51Cr, ... Evaluation of the nuclear excitation functions of fast neutron-induced reactions on 52Cr and 56Fe isotopes. *A Gandhi. 1. , ... In this article, we present the nuclear excitation functions of the fast neutron-induced reactions 52Cr(n,p)52V, 52Cr(n,α)49Ti ... Gandhi, A., Rai, N.K., Prajapati, P.K. et al. Evaluation of the nuclear excitation functions of fast neutron-induced reactions ...
More so than x-rays, neutrons are deeply penetrating even through dense metals. When neutrons scatter off atoms in a material, ... Spallation Neutron Source * ARCS , Wide Angular-Range Chopper Spectrometer , BL-18 * BASIS , Backscattering Spectrometer , BL-2 ... "There are a lot of reasons to use neutrons, but in this case, it allows us to see the diffraction from the individual phases ... Weiss added that neutrons allow them to bypass surface structures or minute defects that form during the manufacturing ...
However, commercially available fast-neutron generators also have the disadvantage of a relatively low yield and fast-neutron ... such as the relatively low yield of commercially available fast-neutron generators, the tendency of fast neutrons to scatter in ... Fast-Neutron Tomography using a Mobile Neutron Generator for Assessment of Steam-Water Distributions in Two-Phase Flows. ... This article proposes the novel technique of fast-neutron tomography using a portable deuterium-tritium neutron generator to ...
Repair of Radiation Damage in Lewis Lung Carcinoma Cells following in Situ Treatment with Fast Neutrons and γ-rays. William U. ... Repair of Radiation Damage in Lewis Lung Carcinoma Cells following in Situ Treatment with Fast Neutrons and γ-rays ... Repair of Radiation Damage in Lewis Lung Carcinoma Cells following in Situ Treatment with Fast Neutrons and γ-rays ... Repair of Radiation Damage in Lewis Lung Carcinoma Cells following in Situ Treatment with Fast Neutrons and γ-rays ...
... and obtains the mass of nuclear materials by utilizing the equation of fast neutron multiplicity. Via GEANT4 tool kit, the ... The paper constructs the model of nuclear materials and fast neutron multiplicity counter, ... Fast neutron, Multiplicity, GEANT4. Abstract. The paper constructs the model of nuclear materials and fast neutron multiplicity ... simulation of fast neutron multiplicity analytical method and lays the foundation of the design and application of fast neutron ...
... has been carried out using a laboratory based D-T neutron generator facility at Bhabha Atomic Research Centre (BARC) and ... An experimental study on fast neutron radiography (FNR) ... Preliminary Experimentation of Fast Neutron Radiography with D- ... Adams, Robert, et al.: A novel fast-neutron tomography system based on a plastic scintillator array and a compact DD neutron ... An experimental study on fast neutron radiography (FNR) has been carried out using a laboratory based D-T neutron generator ...
Fast-neutron-induced and as-grown structural defects in magnesium aluminate spinel crystals with different stoichiometry ... Fast-neutron-induced and as-grown structural defects in magnesium aluminate spinel crystals with different stoichiometry. ... Fast-neutron-induced and as-grown structural defects in magnesium aluminate spinel crystals with different stoichiometry. ...
  • Most fast neutron therapy beams are produced by reactors, cyclotrons (d+Be) and linear accelerators. (wikipedia.org)
  • A fast-neutron reactor (FNR) or simply a fast reactor is a category of nuclear reactor in which the fission chain reaction is sustained by fast neutrons (carrying energies above 0.5 MeV or greater, on average), as opposed to thermal neutrons used in thermal-neutron reactors. (wikipedia.org)
  • Fast reactors lack a moderator, and thus lack one of the systems that remove neutrons from the system. (wikipedia.org)
  • The blanket material can then be processed to extract the 239 Pu to replace losses in the reactor, and the surplus is then mixed with uranium to produce MOX fuel that can be fed into conventional slow-neutron reactors. (wikipedia.org)
  • Given the limited reserves of uranium ore known in the 1960s, and the rate that nuclear power was expected to take over baseload generation, through the 1960s and 1970s fast breeder reactors were considered to be the solution to the world's energy needs. (wikipedia.org)
  • Fast neutron reactors (FNRs) are a technological step beyond conventional power reactors, but are poised to become mainstream. (world-nuclear.org)
  • About 20 fast neutron reactors (FNR) have already been operating, some since the 1950s, and some supplying electricity commercially. (world-nuclear.org)
  • Fast reactors more deliberately use the uranium-238 as well as the fissile U-235 isotope used in most reactors. (world-nuclear.org)
  • If they are designed to produce more plutonium than the uranium and plutonium they consume, they are called fast breeder reactors (FBRs). (world-nuclear.org)
  • Fast neutron reactors also can burn long-lived actinides which are recovered from used fuel out of ordinary reactors. (world-nuclear.org)
  • Several countries have research and development programmes for improved fast neutron reactors, and the IAEA's INPRO programme involving 22 countries (see later section) has fast neutron reactors as a major emphasis, in connection with closed fuel cycle. (world-nuclear.org)
  • For instance one scenario in France is for half of the present nuclear capacity to be replaced by fast neutron reactors by 2050 (the first half being replaced by EPR units). (world-nuclear.org)
  • Reflectors are used in reactors to prevent neutrons escaping. (ukessays.com)
  • By providing the end-users with detailed information on existing and future experimental facilities the open LMFNS database is aimed at facilitating cooperation between organizations with an active programme on fast neutron systems, enhancing the utilization of these facilities within the associated experimental programmes, and motivating the involvement of young engineers and researchers to be educated and trained in the field of advanced reactors. (iaea.org)
  • Neutron Imaging is ideally suited for applications in cultural heritage even at small reactors with moderate image resolution. (mdpi.com)
  • Stability of fast neutron reactors with liquid metal coolant. (physicsforums.com)
  • INTERNATIONAL ATOMIC ENERGY AGENCY, Design Features and Operating Experience of Experimental Fast Reactors, Nuclear Energy Series No. NP-T-1.9, IAEA, Vienna (2013). (iaea.org)
  • Topics covered include the neutron physics of reactor kinetics, feedback effects, water-moderated reactors, fast reactors, and methods of plant control. (elsevier.com)
  • and the neutron kinetics of water-moderated reactors and fast reactors. (elsevier.com)
  • It has also been used to measure fast neutron backgrounds near reactors. (nist.gov)
  • Hi, I was reading about PWR control system and I saw that control rods are stainless steel tubes encapsulating a Hafnium absorber material , it has Excellent mechanical properties and exceptional corrosion-resistance properties allow its use in the harsh environment of a pressurized water reactors and The German research reactor FRM II uses hafnium as a neutron absorber. (physicsforums.com)
  • Understanding this, one of the sectors that began receiving significant investment in Russia is nuclear energy, particularly research on Fast Neutron Reactors (FNR). (washington.edu)
  • Unlike conventional reactors, FNRs allow neutrons to travel fast through the reaction chamber. (zdnet.com)
  • The presence of fast neutron spectra in new reactors is expected to induce a strong impact on the contained materials, including structural materials, nuclear fuels, neutron reflecting materials, and tritium breeding materials. (hindawi.com)
  • Due to limited availability of fast reactors, testing of future reactor materials will mostly take place in water cooled material test reactors (MTRs) by tailoring the neutron spectrum via neutron screens. (hindawi.com)
  • The use of neutron screens technology is imperative within the framework of the materials qualification for the development of Generation IV (GEN-IV) reactors, since their performance can easily and inexpensively simulate the characteristics of a fast neutron flux facility and accomplish power transient experiments. (hindawi.com)
  • it is examining the neutron screens developed to address the lack of fast research reactors in sufficient number. (hindawi.com)
  • New reactors, especially fast spectrum research reactors, are unlikely to be built and licensed in the US for at least the next decade. (niowaveinc.com)
  • Particle accelerator driven neutron sources offer an alternative, and can generate average thermal or fast neutron fluxes of ~10 14 neutrons/cm 2 ∙s without uranium, which is comparable to flux available in nuclear reactors. (niowaveinc.com)
  • the self-sustaining fission reaction spread by neutrons that occurs in nuclear reactors and bombs. (encyclopedia.com)
  • Abstract Neutron crystallography compliments x-ray crystallography in its ability to precisely locate hydrogen and light atoms in various materials. (sbir.gov)
  • abstract = "High-speed neutron tomographies (1-min acquisition) have been acquired during water invasion into air-filled samples of both intact and deformed (ex situ) Vosges sandstone. (hw.ac.uk)
  • The Physics and Dosimetry of Fast Neutrons for Radiotherapy. (dtic.mil)
  • Accurate dosimetry and determination of the biological effectiveness of boron neutron capture therapy (BNCT) is challenging because of the mix of different types and energies of radiation at the cellular and subcellular levels. (mdpi.com)
  • Fast neutrons passive dosimetry with Si - diodes. (irsn.fr)
  • Since several years, Si-diodes have been used for the fast neutron dosimetry in the case of high level exposure, accidental enclosed. (irsn.fr)
  • 3.1 Adjustment methods provide a means for combining the results of neutron transport calculations with neutron dosimetry measurements (see Test Method E1005 and NUREG/CR-5049) in order to obtain optimal estimates for neutron damage exposure parameters with assigned uncertainties. (astm.org)
  • 3.3.1.1 An important problem in reactor surveillance is the determination of neutron fluence inside the pressure vessel wall at locations which are not accessible to dosimetry. (astm.org)
  • For this purpose the earlier developed program (autoTRAK) is modified by introducing the required features such as angular correction for the recoil particles, fluence-to-dose conversion coefficient, detection sensitivity of CR-39 detectors, etc. to make it applicable for neutron spectrometry and dosimetry. (manipal.edu)
  • However, the detectors available for scattered neutron radiation are still inadequate. (sbir.gov)
  • CCD detectors for fast neutron radiography and tomography with a cone beam. (springer.com)
  • The in-house screens have been tested in camera-based neutron imaging detectors in a reactor beamline and compared with a commercially available polypropylene/ZnS(Cu) fast neutron imaging screen and with a BC400 plastic scintillator slab screen. (elsevier.com)
  • All thermal neutron detectors MUST be surronded by a THERMALIZING MODERATOR if used to count FAST neutrons. (fusor.net)
  • It is a statistical thing and tables are available from most manufacturers of moderated SLOW neutron detectors that will let one back interpolate to the fast flux. (fusor.net)
  • 2011). One study using an array of individual fast neutron detectors in the context of cargo scanning for security purposes is detailed in Eberhardt et al. (elsevier.com)
  • In this paper a fast-neutron tomography system based on an array of individual detectors and a purpose-designed compact D-D neutron generator is presented. (elsevier.com)
  • The vast majority of all neutron detectors deployed in RPMs to date relies on He-3 tubes surrounded by neutron moderators. (wikipedia.org)
  • Such a reactor needs no neutron moderator, but requires fuel that is relatively rich in fissile material when compared to that required for a thermal-neutron reactor. (wikipedia.org)
  • The key to reactor design is to carefully lay out the fuel and water so the neutrons have time to slow enough to become highly reactive with the 235 U, but not so far as to allow them to escape the reactor core. (wikipedia.org)
  • Those running on 239 Pu further increase the number of neutrons, because its most common fission cycle gives off three neutrons rather than the mix of two and three neutrons released from 235 U. By surrounding the reactor core with a moderator and then a layer (blanket) of 238 U, those neutrons can be captured and used to breed more 239 Pu. (wikipedia.org)
  • Due to the surplus of neutrons from 239 Pu fission, the reactor produces more 239 Pu than it consumes. (wikipedia.org)
  • A single fast reactor can thereby feed several slow ones, greatly increasing the amount of energy extracted from the natural uranium, from less than 1% in a normal once-through cycle, to as much as 60% in the best existing fast reactor cycles, or more than 99% in the Integral Fast Reactor. (wikipedia.org)
  • To enable more images in a shorter time, a team led by HZB expert Dr. Nikolay Kardjilov optimized the method at NeXT-Grenoble, a recently opened tomography instrument of the Laue-Langevin Institute (ILL), which is supplied with cold neutrons by a 60 Megawatt research reactor. (eurekalert.org)
  • Fast neutron radiography and tomography at a 10 MW research reactor beamline. (springer.com)
  • Fast neutron radiography tests at the YAYOI-reactor, University of Tokyo. (springer.com)
  • China Experimental Fast Reactor (CEFR) has completed physics start-up tests in 2010 and connected the grid on 40%FP in 2011. (asme.org)
  • Chen X, Fan Z, Chen X, Hu D. Measurement of Reaction Rate Distribution and Neutron Spectrum in China Experimental Fast Reactor. (asme.org)
  • Simple and inexpensive ZnS-based fast neutron imaging screens have been developed and their performance has been tested and compared to a commercially available one using the RAD beamline of the 10 MW research reactor of the Budapest Neutron Centre (BNC), Hungary. (elsevier.com)
  • Fast neutron tomography has been performed with both the commercial and the in-house screens on the reactor beamline. (elsevier.com)
  • Therefore, national and international research on fast reactor technology is increasing. (iaea.org)
  • As a part of the IAEA efforts for knowledge preservation and data retrieval, this publication compiles and documents significant aspects of fast reactor engineering development and experience. (iaea.org)
  • The introductory part includes the history, the state of the art and an overview of fast reactor cooling, heat transport and heat conversion systems development. (iaea.org)
  • Shevchenko BN350 nuclear fast reactor and desalination plant situated on the shore of the Caspian Sea . (gutenberg.org)
  • A fast neutron reactor or simply a fast reactor is a category of nuclear reactor in which the fission chain reaction is sustained by fast neutrons . (gutenberg.org)
  • The 4S reactor is a sodium-cooled fast neutron reactor operating at high temperature, capable of providing high temperature steam for steam assisted in situ oilsands production for 30 years between required refueling. (blogspot.co.uk)
  • We studied: the reproducibility of reading and the influence of its repetition, the homogeneity of the lot of diodes studied, the evolution of the signal with the time after irradiation, the influence of the thermal treatment on this evolution, the response of two types of diodes to the neutrons of SILENE reactor in two configurations, the detection threshold expressed in tissue kerma. (irsn.fr)
  • In this work a comprehensive compilation of the existing neutron screen technology is attempted, focusing on neutron screens developed in order to locally enhance the fast over thermal neutron flux ratio in a reactor core. (hindawi.com)
  • Neutronic conditions similar to the ones prevailing in fast reactor cores can be achieved in MTRs by tailoring the neutron spectrum in order to properly tune the reaction rates. (hindawi.com)
  • In order to reproduce the irradiation conditions prevailing in a sodium-cooled fast reactor (SFR) environment or in a sodium-cooled fast breeder reactor (SFBR), coolant loops and booster fuels are combined in the irradiation facility. (hindawi.com)
  • These accelerator driven neutron sources are licensed as an accelerator and target, not a reactor, which greatly simplifies and expedites the licensing process. (niowaveinc.com)
  • To reveal the material's magnetic structure, the team used the Neutron Powder Diffractometer and Polarized Triple Axis Spectrometer instruments at ORNL's High Flux Isotope Reactor-a DOE Office of Science User Facility. (newswise.com)
  • Neutron Cross Sections for Fast Reactor Materials. (barnesandnoble.com)
  • By comparison, the charged particles produced at a site of a neutron interaction may deliver their energy at a rate of 30-80 keV/µm. (wikipedia.org)
  • By contrast, the high LET charged particles produced from neutron irradiation cause many ionizations as they traverse a cell, and so double-strand breaks of the DNA molecule are possible. (wikipedia.org)
  • An attempt has been made to calculate the response of T.I. kidney cells in tissue culture to these four beams of neutrons, based on their response to charged particles using the track-segment method. (osti.gov)
  • Protons are the positively charged particles in an atom, while neutrons are subatomic particles that h. (reference.com)
  • The ideal detector would provide fast response, high spatial resolution, high neutron efficiency, low gamma sensitivity, and large detection area at reasonable cost. (sbir.gov)
  • In Phase I, a 5 x 5 cm2 prototype sensor will be fabricated and evaluated using a novel CCD-based detector and a PSPMT at neutron beam facilities. (sbir.gov)
  • The detector, along with its components (e.g., the structured plastic scintillator) could be employed at any neutron source facility and would advance basic research in material science, protein mechanisms, and drug design. (sbir.gov)
  • We need a bubble neutron detector, but we know the company in Canada has a minimun order of $300. (fusor.net)
  • So, could you sell a bubble neutron detector to us? (fusor.net)
  • BF 3 detector is used for detection of thermal neutron. (ukessays.com)
  • Instrument upgrades are foreseen by introducing a more powerful neutron generator and by adding detector elements, speeding up the data collection by several orders of magnitude and allowing for higher precision data. (diva-portal.org)
  • Fast neutron fields imaging with a CCD-based luminescent detector. (springer.com)
  • This image shows a Bonner Ball Neutron Detector which is housed inside the small plastic ball when the top is put back on. (wikiversity.org)
  • We are developing a detector that uses liquid scintillator loaded with 6 Li for the efficient measurement of fast neutrons and their energy. (nist.gov)
  • The detector will use a commercial liquid scintillator that we have doped with enriched Li-6 to act as the neutron capture agent. (nist.gov)
  • The detector is being used to measure the fast neutrons induced by cosmic rays at the Earth's surface and in shallow underground locations. (nist.gov)
  • The Arktis full range detector provides a unique combination of fast and thermal neutron detection , simple integration, spectral information and unbeatable robustness. (environmental-expert.com)
  • He3 counter - A THERMAL neutron detector tube similar to the BF3 tube, but a bit more efficient. (fusor.net)
  • Fission counter - A FAST neutron counter based on The U-238 + n reaction inducing a fission of the U238 contained in the detector tube. (fusor.net)
  • Solid angle - the effective angle subtended between a point source of neutrons at the center of an imaginary sphere and the detector's effective cross sectional area at the surface of this same imaginary sphere of radius "r" (the distance from the center of the source to the center of the detector. (fusor.net)
  • An attempt is made to estimate the neutron spectrum using the CR-39 (Solid state nuclear track) detector and a new image analyzing program. (manipal.edu)
  • X-rays produce low LET radiation, and protons and neutrons produce high LET radiation. (wikipedia.org)
  • Most nuclear effects involve only the nucleus, which is made up of protons and neutrons. (scribd.com)
  • What are protons and neutrons called? (reference.com)
  • Protons and neutrons make up the nucleus of the atom, which is the densely packed center. (reference.com)
  • However, there are also challenges, such as the relatively low yield of commercially available fast-neutron generators, the tendency of fast neutrons to scatter in the interactions with materials and the relatively low efficiency encountered in fast-neutron detection. (diva-portal.org)
  • The neutron detection temperature , also called the neutron energy , indicates a free neutron's kinetic energy , usually given in electron volts . (wikiversity.org)
  • We continue to work improving techniques in fast neutron detection using segmented spectrometers based on the principle of capture-gating. (nist.gov)
  • We discuss the operation of the spectrometers for the measurement of low levels of fast neutrons for several applications, including the detection of very low-activity neutron sources and the characterization of the flux and spectrum of fast neutrons at the Earth's surface and in the underground environment. (nist.gov)
  • BF3 tube/counter - a THERMAL neutron detection tube or counter based on the boron tri-floride high neutron cross section reaction (B10 + n = Li7 + a) for detection. (fusor.net)
  • Its principal applications are fast neutron spectrometry and thermal neutron detection. (scribd.com)
  • Gamma radiation is detected, and in some cases complemented by neutron detection when sensitivity for nuclear material is desired. (wikipedia.org)
  • RPMs geared for interception of nuclear threats usually incorporate a neutron detection technology. (wikipedia.org)
  • The search for alternative neutron detection technologies has yielded satisfactory results. (wikipedia.org)
  • Introducing moderators and lithium-6 to capture thermalized neutrons further increases the detection capabilities of natural helium, at the expense of losing the initial information of the neutrons (such as energy) and reducing sensitivity to shielded neutron-emitting materials. (wikipedia.org)
  • Cold neutrons are employed at the ANTARES facility, and fission neutrons are available at the NECTAR facility to penetrate large samples. (mdpi.com)
  • The term temperature is used, since hot, thermal and cold neutrons are moderated in a medium with a certain temperature. (wikiversity.org)
  • 2 MeV) is too low to create sufficient fission in 238 U, and the flux of lower-energy fission neutrons ( (wikipedia.org)
  • Fission neutrons permit the examination of large samples that otherwise show large attenuation for thermal neutrons. (mdpi.com)
  • Zhang W, Endo S, Ishikawa M, Ikeda H, Hoshi M. Relative biological effectiveness of fission neutrons for producing micronuclei in the root-tip cells of onion seedlings after irradiation as dry seeds. (radiationjournal.org)
  • Generally it is believed that neutron irradiation overcomes the effect of tumor hypoxia, although there are counterarguments The efficacy of neutron beams for use on prostate cancer has been shown through randomized trials. (wikipedia.org)
  • It is expected that postoperative irradiation of fast neutron will decrease local recurrence of adenocarcinoma of the uterus. (osti.gov)
  • Photograph of the FaNS-2 acquiring data in the Californium Neutron Irradiation Facility (CNIF) at NIST. (nist.gov)
  • Morphological and Phenotypic Effects of Fast Neutron Irradiation (FNI) on Lagos Spinach ( Celosia argentea L. (radiationjournal.org)
  • Fast neutrons irradiation is a valuable tool for developing varieties with high agricultural potentials and economic values. (radiationjournal.org)
  • Therefore, the research was carried to evaluate effects of fast neutron irradiation on the morphology and phenotype of Lagos spinach, with the aim of inducing useful agronomical traits for selection of desirable genotypes that could be used for large scale production. (radiationjournal.org)
  • Abubakar Abdulhakeem, Falusi Ahmed Olamide, Daudu Oladipupo Abdulazeez Yusuf, Morphological and Phenotypic Effects of Fast Neutron Irradiation (FNI) on Lagos Spinach ( Celosia argentea L.), Radiation Science and Technology . (radiationjournal.org)
  • Generation of peanut mutants by fast neutron irradiation combined with in vitro culture. (radiationjournal.org)
  • Effect of Fast Neutron Irradiation (FNI) on pollen germinability of three Nigerian sesame varieties. (radiationjournal.org)
  • The influence of a low dose [1mGy] of fast neutron irradiation on the molecular structure of proteins extracted from the yeast fungi Rhodotorula rubra and Hansenuala anomala was investigated. (bvsalud.org)
  • The combined dosimetric and radiobiological model includes an analytical formulation that accounts for the type of neutron source, the tissue- or cancer-specific dose-response characteristics, and the microdistribution of boron. (mdpi.com)
  • Tests of the model against results from published experiments with and without boron show good agreement between modeled and experimentally determined cell survival for neutrons alone and in combination with boron. (mdpi.com)
  • Boron neutron capture therapy (BNCT) has been investigated as a potential treatment for glioblastoma multiforme (GBM), head and neck cancers, melanoma, and other tumor sites for many decades. (mdpi.com)
  • Although efforts to develop neutron sources and new boron delivery agents for BNCT are ongoing [ 1 ], boronophenylalanine (BPA) and sodium borocaptate (BSH) are currently the only boron compounds approved for use in clinical trials [ 2 ]. (mdpi.com)
  • Recently, a new application of boron neutron capture therapy (BNCT) treatment has been introduced. (nih.gov)
  • A neutron generator comprising a boron-10 bearing target and a low-energy accelerator, wherein said low-energy accelerator emits a plurality of particles which bombard said boron-10 bearing target to cause a 10 B(d,n) 11 C reaction which in turn produces a plurality of neutrons having an energy value greater than about 2 MeV and less than about 8 MeV. (freepatentsonline.com)
  • 3. The neutron generator of claim 1, wherein said low-energy accelerator is a field emission ion source coupled with a single gap accelerator to accelerate said plurality of deuterons on said boron-10 bearing target. (freepatentsonline.com)
  • 4. The neutron generator of claim 1 further comprising an ion source chamber, an antenna coupled to the ion source chamber, and said boron-10 bearing target having a plurality of magnets within the target such that the generator produces said plurality of neutrons having an energy value greater than about 2 MeV and less than about 8 MeV. (freepatentsonline.com)
  • 5. The neutron generator of claim 1, wherein boron-10 bearing target comprises lanthanide hexaboride (LaB 6 ). (freepatentsonline.com)
  • 9. The neutron generator of claim 1, wherein said particle used to bombard the boron-10 bearing target does not include any triton (T-T) or tritium containing particle. (freepatentsonline.com)
  • Like boron hafnium is nearly transparent to fast neutrons. (physicsforums.com)
  • Boron counter tube - A tube containing a boron coating on the inside wall of the tube to detect thermal neutrons. (fusor.net)
  • For the spectrum tailoring two options are offered, that is, either (a) to remove the thermal component using a neutron screen technique based for example, on Cadmium, Boron, or Hafnium shields, or (b) to increase the fast/thermal neutrons ratio inside an MTR by using fissile material. (hindawi.com)
  • The primary function of the boron is to provide a unique scintillation signal for low energy neutrons. (scribd.com)
  • The reaction rate distribution, neutron spectrum are some important parameters for CEFR neutron field. (asme.org)
  • Neutron spectrum was measured by means of multifoil activation method. (asme.org)
  • And a neutron spectrum adjusting code was also compiled to determine the neutron spectrum. (asme.org)
  • The group neutron spectrum is usually not reported since that would be a tremendous volume of data over time/burnup for even 1/8 or 1/4 of an assembly. (physicsforums.com)
  • Normally, one does not look at the neutron energy spectrum in the coolant or fuel, unless one is digging into the details of a calculation, e.g., looking at specific cross-sections, or effects of specific nuclides/isotopes. (physicsforums.com)
  • The neutron energy spectrum was measured from March 23, 2001 through November 14, 2001 in the U.S. Laboratory Module of the ISS. (wikiversity.org)
  • The central neutron spectrum of the Big Ten Critical Assembly, a cylindrical assembly with a 10% enriched uranium metal core surrounded by a depleted uranium metal reflector, has been measured between 32 keV and 1177 keV, using proton recoil proportional counting techniques. (tamu.edu)
  • The neutron spectrum was determined from the recoil proton data by response function unfolding. (tamu.edu)
  • The results of the spectrum measurements are compared with a transport theory computation of the neutron spectrum using E.N.D.F./B-III cross-section sets. (tamu.edu)
  • Three teeth were successively irradiated first with fast neutrons with a wide energy spectrum (mean energy around 30 MeV) up to approximately 160 Gy and then with gamma-rays up to approximately 14 Gy. (uclouvain.be)
  • A neutron screen is a device, a model, a system, or a technology that provides the capability of locally tailoring the neutron spectrum. (hindawi.com)
  • Spectrum tailoring is accomplished by using absorbing materials-acting as a filter to neutrons with specific energies-affecting thus the flux to which the specimen is exposed. (hindawi.com)
  • A neutron screen achieves the required fast neutron environment by cutting off the thermal component of the neutron spectrum, using thermal neutron absorbing material. (hindawi.com)
  • The neutron spectrum can be tailored for fast or thermal spectra depending on the reflectors and moderators used. (niowaveinc.com)
  • Natural uranium consists mostly of three isotopes: 238 U, 235 U, and trace quantities of 234 U (a decay product of 238 U). 238 U accounts for roughly 99.3% of natural uranium and undergoes fission only by fast neutrons. (wikipedia.org)
  • When either of these isotopes undergoes fission, it releases neutrons with an energy distribution peaking around 1 to 2 MeV. (wikipedia.org)
  • The release of neutrons from the nucleus requires exceeding the binding energy of the neutron, which is typically 7-9 MeV for most isotopes . (wikipedia.org)
  • When either of these isotopes undergoes fission they release neutrons around 1 to 2 MeV, too low to cause fission in U-238, and too high to do so easily in U-235. (gutenberg.org)
  • Since the charge is what characterizes an element, nuclei with different numbers of neutrons in the nucleus, but the same number of protons, are called isotopes of that element. (scribd.com)
  • For example, there are three isotopes of hydrogen that have none, one, or two neutrons in the nucleus. (scribd.com)
  • The curved slab neutron coincidence slab counter measures the plutonium content of the sample by detecting coincidence neutrons from the spontaneous fission of the even numbered isotopes of plutonium. (canberra.com)
  • The JCC-41, which is based on Monte Carlo design calculations performed at Los Alamos National Laboratory, measures the effective 240 Pu mass in a sample by detecting coincidence neutrons from the spontaneous fission of the even numbered isotopes of plutonium. (canberra.com)
  • The neutron is uncharged and damages cells by direct effect on nuclear structures. (wikipedia.org)
  • Neutron therapy is a very powerful nuclear scalpel that has to be utilized with exquisite care. (wikipedia.org)
  • This kind of information can enhance the basic understanding of the mechanism of the fast neutron-induced nuclear reactions. (springer.com)
  • The paper constructs the model of nuclear materials and fast neutron multiplicity counter, and obtains the mass of nuclear materials by utilizing the equation of fast neutron multiplicity. (atlantis-press.com)
  • Portable fast-neutron radiography with the nuclear materials identification system for fissile material transfers. (springer.com)
  • Development of a fast neutron imaging system for investigating two-phase flows in nuclear thermal-hydraulic phenomena: a status report. (springer.com)
  • The LMFNS Catalogue is a useful tool for a wide range of governmental and private sector organizations responsible for the development and/or deployment of innovative fast neutron systems in countries with active programmes on these nuclear energy systems. (iaea.org)
  • In nuclear engineering , a neutron moderator is a medium that reduces the speed of fast neutrons , ideally without capturing any, leaving them as thermal neutrons with only minimal (thermal) kinetic energy . (wikipedia.org)
  • These thermal neutrons are immensely more susceptible than fast neutrons to propagate a nuclear chain reaction of uranium-235 or other fissile isotope by colliding with their atomic nucleus . (wikipedia.org)
  • Neutron sources generate free neutrons by a variety of nuclear reactions, including nuclear fission and nuclear fusion . (wikipedia.org)
  • From a nuclear standpoint, the primary problem is that water can absorb a neutron and remove it from the reaction. (gutenberg.org)
  • 10. A method for detecting a nuclear material, explosive or drug comprising: generating a plurality of neutrons using a neutron generator of claim 1 the direction of an object of interest, such that if said object contained a nuclear material, explosive or drug then said nuclear material, explosive or drug would be detected. (freepatentsonline.com)
  • Here, is a quick look at alternative fuels and designs that would support a safer nuclear future, from the standpoint of both operational safety and weapons-grade waste. (zdnet.com)
  • Theoretical calculations of neutron-induced reactions on 59 Co were performed using the nuclear model code TALYS-1.9. (ihep.ac.cn)
  • The total flux to which the bacteria were subjected was approximately 10 12 neutrons/cm 2 and the sensitive area was estimated to be lO -l2 cm 2 . (vt.edu)
  • Some nuclei have larger absorption cross sections than others, which removes free neutrons from the flux . (wikipedia.org)
  • H 2 O. So the multi-group neutron flux in coolant and fuel pin has much diffenrce, e.g. the relative higher fast neutron in fuel pin and relative higher thermal neutron in coolant as to the uniform. (physicsforums.com)
  • SIMULATE or PANTHER, respectively, to calculate the neutron flux and fission density. (physicsforums.com)
  • This larger volume gives a greater sensitivity to the fast neutron flux and a larger dynamic range of approximately 1 MeV to 1 GeV. (nist.gov)
  • Neutron counter - any full and complete instrument designed to detect neutrons and present a neutron count or neutron absorbed doseage related measurment when placed in a neutron flux. (fusor.net)
  • Neutron flux - A specific number of neutrons passing through a specific area in unit time. (fusor.net)
  • To thermalize a given surface flux of FAST neutrons they are scattered and the net effect is to reduce the thermalized flux intercepted by the tube. (fusor.net)
  • High flux neutron sources are needed for a broad range of materials research and for radioisotope production. (niowaveinc.com)
  • As an example, our 40 MeV, 100 kW continuous wave (CW) superconducting linac can produce a fast neutron flux up to 10 14 neutrons/cm 2 ∙s using a liquid lead target without uranium for testing of Generation IV materials. (niowaveinc.com)
  • An example distribution of the neutron flux is shown below in Figure 1. (niowaveinc.com)
  • Neutron flux generated within a 3 x 3 cm high-Z target. (niowaveinc.com)
  • The practical methods for generating fast-neutron beams for cancer radiotherapy are compared (DT versus D on Be). (dtic.mil)
  • Neutron-beam radiotherapy systems designed to deliver a high-energy fast-neutron beam. (medicalproductguide.com)
  • Fast-neutron radiotherapy is used in selected clinical indications, such as inoperable sarcomas of bone and soft tissues and advanced salivary gland tumors. (medicalproductguide.com)
  • MCNP simulations were performed in order to find a moderator configuration for creating a neutron beam of optimal neutron energy and to create a source model for dose calculations with the simulation environment for radiotherapy applications (SERA) treatment planning program. (nih.gov)
  • By exploiting the much more intense neutron beam, it has been possible to reduce the recording time per tomogram to almost one second. (eurekalert.org)
  • The energy spectra of neutrons emitted by thick deuterium and helium targets at 0° angle irradiated by a beam of 15.8 MeV protons, 14.1 MeV and 17.1 MeV deuterons, respectively, were measured in an open geometry with stilbene and NE 213 scintillators and with a two-dimensional n-γ discrimination technique. (astm.org)
  • A general effort is made to compare and contrast the interactions and depth-dose patterns for gamma ray beams with those for the NRL fast-neutron beam of app. (dtic.mil)
  • Narrow-broad-beam attenuation coefficients for 60 Co gamma rays vs the NRL neutron beam are shown for a variety of materials, and some semi-broad-beam data for Benelex (pressed wood), Pb, and Fe are also included. (dtic.mil)
  • The neutron beam intensity is decreased by transmission across material. (ukessays.com)
  • Fast neutron radiation using modern imaging, treatment planning, and beam delivery was feasible to a total dose of 18 Gy, but tumor control probability was poor in comparison to that predicted from a dose-response model based on older studies. (elsevier.com)
  • In this paper, the beam shaping assemblies for D-D and D-T neutron generators and dose calculation results are presented. (nih.gov)
  • The electron beam impinges on a high-Z liquid metal target to generate x-rays and then neutrons via (γ, n) reactions. (niowaveinc.com)
  • The neutrons were generated from the 9 Be( p , n ) reaction with proton beam energies of 25-45 MeV at the MC-50 Cyclotron facility of the Korean Institute of Radiological and Medical Sciences (KIRAMS). (ihep.ac.cn)
  • The RBE of neutrons is also energy dependent, so neutron beams produced with different energy spectra at different facilities will have different RBE values. (wikipedia.org)
  • Distributions of stopping power (LET) are given for four beams of fast neutrons, namely, neutrons of 14.6 MeV, neutrons produced by bombarding a thick beryllium target with 15 MeV deuterons, neutrons of 3 MeV, and fast neutrons produced by bombardment of a {sup 235}U converter plate with thermal neutrons. (osti.gov)
  • The calculated RBE's of the neutron beams are lower than the observed values and the calculated values of the oxygen enhancement ratio are higher. (osti.gov)
  • Although doses of BPA are non-toxic at levels as high as 250 mg BPA/kg of body weight and tumor to blood ratios up to 3.5:1 [ 3 ], the use of non-conformal thermal and epithermal neutron beams is limited by the dose to normal brain tissue. (mdpi.com)
  • Graul E.H. (1980) Medical Considerations in Radiation Accidents and the Biologic Effect of Fast Neutrons in Hydrogen Bomb Explosions. (springer.com)
  • 239 Pu has a neutron cross section similar to that of 235 U, and most of the atoms created this way will undergo fission from the thermal neutrons. (wikipedia.org)
  • If the fuel is enriched, eventually a threshold will be reached where there are enough fissile atoms in the fuel to maintain a chain reaction even with fast neutrons. (wikipedia.org)
  • When neutrons scatter off atoms in a material, they provide researchers with a wealth of structural information down to the atomic scale. (ornl.gov)
  • In order to sustain a fission chain reaction , the neutrons released in fission events have to react with other atoms in the fuel. (gutenberg.org)
  • most atoms will only undergo induced fission with high energy neutrons, although a smaller number prefer much lower energies. (gutenberg.org)
  • This means that if you enrich the fuel you will eventually reach a threshold where there are enough fissile atoms in the fuel that a chain reaction can be maintained even with fast neutrons. (gutenberg.org)
  • Most important in capture cross sectional studies and neutron resonances within atoms. (fusor.net)
  • Neutron scattering - Neutrons are scattered in most materials of high cross section through the action of multiple short range impacts with atoms of the moderator. (fusor.net)
  • These B10 atoms are the only ones which can interact with neutrons for the idealized counter reaction. (fusor.net)
  • It can absorb a neutron and remove it from the reaction. (wikipedia.org)
  • The downside to the fast reaction is that fuel enrichment is an expensive process, so this is generally not suitable for electrical generation or other roles where cost is more important than size. (wikipedia.org)
  • Another advantage to the fast reaction has led to considerable development for civilian use. (wikipedia.org)
  • The p+D reaction looks to be the most effective reaction for producing fast neutrons on low energy cyclotrons. (astm.org)
  • Moreover, we have studied the contribution from different reaction mechanisms in total reaction cross-section which varies with the incident neutron energy. (springer.com)
  • The neutrons were obtained from the H³(d,n)He⁴ reaction produced in the Cockeroft-Walton accelerator at Virginia Polytechnic Institute. (vt.edu)
  • The reaction provides a neutron source which is almost monoenergetic, symmetrical, has a low level of associated gamma rays, and gives a large number of neutrons per unit time. (vt.edu)
  • C may be produced even before neutrons thermalize for the expected reaction. (wikiversity.org)
  • The neutron found in the fusion reaction with deuterium in the fusor has an energy of 2.45 mev. (fusor.net)
  • In the case of the fission of a nucleus, the reaction is begun by the absorption of a slow neutron. (encyclopedia.com)
  • In order to sustain a chain reaction, a sample must be large enough to slow the neutrons so that one can be captured by another nucleus and produce a second fission. (encyclopedia.com)
  • Epithermal neutrons - neutrons with energies between 1ev and about 1kev, though there is no hard line drawn. (fusor.net)
  • The absorber is almost transparent to fast-and much less to epithermal-neutrons. (hindawi.com)
  • Our approach employs an organic scintillator to detect fast neutrons through their recoil interaction with protons in the scintillator. (nist.gov)
  • The latest technology being deployed at ports uses pressurized natural helium to directly detect fast neutrons, without the need for bulky neutron moderators. (wikipedia.org)
  • This is fundamental physics that's important in a much larger sense than just studying neutron stars," he told New Scientist . (newscientist.com)
  • This thesis describes the measurement technique of fast-neutron tomography for assessing spatial distributions of steam and water in two-phase flows. (diva-portal.org)
  • A novel fast-neutron tomography system based on a plastic scintillator array and a compact DD neutron generator. (springer.com)
  • Radiography and tomography with fast neutrons at the FRM-II-a status report. (springer.com)
  • The rate of coincidental and correlated hits in multiple scintillator bars was the primary investigation, in order to further understand the sensitivity of the plastic scintillators to fast neutrons. (aps.org)
  • Being sensitive to both fast and thermal neutrons allows greater sensitivity and optimized performance even when shielding is present. (environmental-expert.com)
  • Sensitivity of whole human teeth to fast neutrons and gamma-rays estimated by L-band EPR spectroscopy. (uclouvain.be)
  • This paper reports the first attempt to use L-band spectroscopy for estimating the sensitivity of whole teeth to fast neutrons and gamma-rays. (uclouvain.be)
  • Neutrons are well suited for investigating magnetic materials given their sensitivity to the organization and dynamics of electrons' spins at the microscopic scale. (newswise.com)
  • Characterization of oil and protein profile in soybean fast neutron mutants will assist scientist and breeders to develop new value-added soybeans with improved protein and oil quality traits. (springer.com)
  • Fast-Neutron Soybean Mutagenesis Project - Characterization of Mutant Lines Possessing Unique Compositional Characteristics. (umn.edu)
  • These systems include a source of fast neutrons (e.g., cyclotrons, linear accelerators), a control unit, and appropriate filters and collimators. (medicalproductguide.com)
  • ORNL and Eck Industries R&D staff are using the VULCAN instrument at the Spallation Neutron Source to examine iterations of their cerium-aluminum alloy. (ornl.gov)
  • Now, the aluminum casting company is looking to unlock even more functionality from the alloy through rigorous testing using neutrons at ORNL's Spallation Neutron Source (SNS). (ornl.gov)
  • Although 238 U does not undergo fission by the neutrons released in fission, thermal neutrons can be captured by the nucleus to transmute the uranium into 239 Pu. (wikipedia.org)
  • Whatever the source of neutrons, they are released with energies of several MeV. (wikipedia.org)
  • U-238 accounts for roughly 99.3% of natural uranium and undergoes fission only by neutrons with energies of 5 MeV or greater, the so-called fast neutrons . (gutenberg.org)
  • In such situations scattering of neutrons at or near thermal energies can further reduce the net efficiency of the BF3 FAST counter (NOT THE TUBE)! (fusor.net)
  • These bars were placed in series in front of a deuterium-deuterium neutron generator, which produced fast neutrons of approximately 2.8MeV. (aps.org)
  • An experimental study on fast neutron radiography (FNR) has been carried out using a laboratory based D-T neutron generator facility at Bhabha Atomic Research Centre (BARC) and initial results are presented. (springer.com)
  • The experimental set-up consists of a D-T neutron generator, collimator and an EMCCD camera based imaging system. (springer.com)
  • Experiments were carried out with the neutron generator having a source strength of about 2 × 10 9 n/s and source spot size of 20 mm. (springer.com)
  • The initial results emphasizes that a moderate yield D-T neutron generator based fast neutron radiography system with EMCCD camera could be deployed for field applications yielding moderate image quality to obtain first hand information of the investigated samples. (springer.com)
  • 2. The neutron generator of claim 1, wherein said particles emitted by said low-energy accelerators comprises a plurality of deuterons (D-D). (freepatentsonline.com)
  • 6. The neutron generator of claim 1, wherein the neutrons produced by the neutron generator have an energy value greater than about 2 MeV and less than about 6 MeV. (freepatentsonline.com)
  • 8. The neutron generator of claim 1, wherein said low-energy accelerator is not a radio-frequency quardrupole (RFQ) accelerator. (freepatentsonline.com)
  • Very few experimental imaging studies using a compact neutron generator have been published, and to the knowledge of the authors none have included tomography results using multiple projection angles. (elsevier.com)
  • Radiography results with a neutron generator, scintillator screen, and camera can be seen in Bogolubov et al. (elsevier.com)
  • 2014) three fast neutron counters and a D-T generator were used to perform attenuation measurements of test phantoms. (elsevier.com)
  • The sample must also be compact to prevent neutrons from escaping. (encyclopedia.com)
  • About 0.7% of natural uranium is 235 U, which undergoes fission by neutrons of any energy, but particularly by lower-energy neutrons. (wikipedia.org)
  • With a small quantity of low-enriched uranium (LEU), these accelerator driven sources can generate average thermal or fast fluxes of ~10 16 neutrons/cm 2 ∙s. (niowaveinc.com)
  • the neutrons lost through absorption in the water and 238 U, along with those lost to the environment, results in too few left in the fuel. (wikipedia.org)
  • The absorption cross section of 10 B is large for absorbing of thermal neutrons. (ukessays.com)
  • As the neutrons have essentially the same mass as protons and there is no absorption, the velocity distributions of both particles types would be well-described by a single Maxwell-Boltzmann distribution . (wikipedia.org)
  • It should be noted that several complexities, mainly of technological nature, are involved in the use of thermal neutron absorption shields, since all candidate shielding materials have their specific problems induced by welding behaviour, swelling (e.g. (hindawi.com)
  • The team, David Weiss (left), Orlando Rios, Hunter Henderson, and Zach Sims, are using neutrons to probe the atomic structures to design the alloys with optimal properties to meet industry demands. (ornl.gov)
  • For competitors, gaining the upper hand could ultimately be determined by how well they understand their manufacturing materials at the atomic scale and how quickly they can incorporate research and development insights into new production designs. (ornl.gov)
  • Neutrons are normally bound into an atomic nucleus , and do not exist free for long in nature. (wikipedia.org)
  • Dr. Robert Georgii ( TUM ) and a colleague from the neutron source ISIS in the United Kingdom are working with a PhD student to develop a concept for a novel crystal time-of-flight spectrometer (€0.2 million) that can measure the structures and movements of matter on an atomic scale with time and spatial resolution. (mlz-garching.de)
  • The proton has a mass of 1.007897 atomic mass units (AMU) and a single positive unit of charge, while the neutron has a mass of 1.009268 AMU and has no charge. (scribd.com)
  • This gives it an atomic weight of around 75, which is determined by adding the 42 neutrons to arsenic's 33 protons. (reference.com)
  • How many protons, neutrons and electrons an atom has determines what element it is, though on the periodic table of elements, the atomic number is based on the number of protons an element has. (reference.com)
  • Atomic mass is the total mass of protons, neutrons, and electrons in a given element, commonly expressed in unified atomic mass units. (reference.com)
  • The scintillator will be loaded with neutron sensitive elements, such as B and Gd. (sbir.gov)
  • Commercial Applications and Other Benefits as described by the awardee: The modified scintillator should find widespread in neutron radiography and neutron crystallography. (sbir.gov)
  • The segmentation permits reconstruction of the initial neutron energy despite the nonlinear response of the scintillator. (nist.gov)
  • A construction of a prototype Fast Neutron Spectrometer (FaNS-1) consisting of six He-3 proportional counters placed between six large blocks of plastic scintillator was completed and assembled at Kimballton Underground Research Facility near Blacksburg, VA, as seen in the photograph. (nist.gov)
  • A combined in-situ infrared spectrometer for neutron small-angle scattering systems is being designed by RWTH Aachen together with Dr. Tobias Schrader from Forschungszentrum Jülich. (mlz-garching.de)
  • Neutrons are sensitive mainly to light elements such as hydrogen, lithium and their compounds. (eurekalert.org)
  • The scattering cross section of hydrogen is high for neutrons. (ukessays.com)
  • So, hydrogen containing material such as polyethylene and hydrocarbon are used for neutron shielding [1]. (ukessays.com)
  • In a system at thermal equilibrium, neutrons (red) are elastically scattered by a hypothetical moderator of free hydrogen nuclei (blue), undergoing thermally activated motion. (wikipedia.org)
  • And traditionally, the neutron absorbing material is sealed in a tube of SS-304 or 316, and stainless steel is somewhat permeable with respect to hydrogen. (physicsforums.com)
  • The second simplest nucleus belongs to another type of hydrogen called deuterium, consisting of a proton and neutron. (scribd.com)
  • Utilizing recoil nuclei following neutron scatter events, natural helium glows (scintillates), allowing photomultipliers (e.g. (wikipedia.org)
  • By deploying portable neutron generators in transmission tomography, the technique becomes applicable to stationary objects, such as thermal-hydraulic test loops. (diva-portal.org)
  • The neutrons that thermalize and are captured produce a signal indicating that the event was due to a neutron recoil and that the full energy of the neutron was deposited. (nist.gov)
  • The most common moderator is water, which acts by elastic scattering until the neutrons reach thermal equilibrium with the water. (wikipedia.org)
  • Thermal neutrons - Neutrons with an energy at or below .02ev which puts it in thermal equilibrium with air molecules at room temperature. (fusor.net)
  • Investigation of neutron production by break-up processes in light-nuclei reactions is described. (astm.org)
  • Given the mathematics of elastic collisions , as neutrons are very light compared to most nuclei, the most efficient way of removing kinetic energy from the neutron is by choosing a moderating nucleus that has near identical mass. (wikipedia.org)
  • Since the Berlin neutron source of the HZB will cease operation in December, the fast imaging set-up will be integrated into the NeXT instrument in Grenoble in order to be able to investigate fast transport processes in other materials in the future. (eurekalert.org)
  • I don't yet have a neutron source but I can make up gels and sent them to Richard or someone else with a working source for testing. (fusor.net)
  • The aim was to develop an FNR system with a moderate intensity neutron source for imaging of specimen containing mixed low-Z and high-Z materials. (springer.com)
  • Smartphone oversharing, the search for where memories live, a source for fast radio bursts, revisiting the honeybee mystery, a robot snailfish, pulsar navigation, secrets of ultrablack feathers and more. (sciencenews.org)
  • Absolute,Isotropic neutron emission rate - The total or absolute number of neutrons emitted from a more or less idealized point source of neutrons per unit time. (fusor.net)
  • i.e. the irradiance or brightness of a neutron source. (fusor.net)
  • After penetrating enough thickness of any moderating material, the neutrons are so scattered that the direction of their original source can no longer be determined as they appear to be coming from everywhare. (fusor.net)
  • Since this counter does not have end plugs, the axial response will fall quickly as the source is moved near the ends of the counter. (canberra.com)
  • This upgraded program (autoTRAK_n) is tested with a mono-energetic source (D-T) and two other standard neutron sources, viz. (manipal.edu)
  • Using the complete array, several fast-neutron images of test phantoms were reconstructed, one of which was compared with results using a Co-60 gamma source. (elsevier.com)
  • The UW Medical Cyclotron Facility where fast neutron therapy is administered is the only clinical neutron facility in the U.S. (uwmedicine.org)
  • Conclusions from this picture of neutron penetration in sodium are made as to the types of transport calculations that can be successfully made in shield design, and the accuracies needed in future cross section measurements. (unt.edu)
  • The time frame enabled neutron measurements to be made during a time of increased solar activity (solar maximum) as well as observe the results of a solar flare on November 4, 2001. (wikiversity.org)
  • Monoenergetic neutron measurements were carried out at the LASL high current Van De Graaff and the Cockcroft-Walton Accelerator in order to test the accuracy of the computed response functions. (tamu.edu)
  • Moderation is the process of the reduction of the initial high speed (high kinetic energy) of the free neutron. (wikipedia.org)
  • Qualitatively, the higher the temperature, the higher the kinetic energy is of the free neutron. (wikiversity.org)
  • At Lawrence Berkeley National Laboratory, compact neutron generators based on (2)H(d,n)(3)He (D-D) or (3)H(t,n)(4)He (D-T) fusion reactions are being developed. (nih.gov)
  • The probability of scattering of a neutron from a nucleus is given by the scattering cross section . (wikipedia.org)
  • As the energy of the neutron is lowered, the collisions become predominantly elastic , i.e., the total kinetic energy and momentum of the system (that of the neutron and the nucleus) is conserved. (wikipedia.org)
  • A collision of a neutron, which has mass of 1, with a 1 H nucleus (a proton ) could result in the neutron losing virtually all of its energy in a single head-on collision. (wikipedia.org)
  • From a large population of fast neutron mutagenized plants, we selected ten mutants based on a screening of total oil and protein content using near infra-red spectroscopy. (springer.com)
  • Fast methane diffusion at the interface of two clathrate structures, Nature Communications (2017). (phys.org)
  • Another advantage is the established ability of neutrons to better treat some cancers, such as salivary gland, adenoid cystic carcinomas and certain types of brain tumors, especially high-grade gliomas When therapeutic energy X-rays (1 to 25 MeV) interact with cells in human tissue, they do so mainly by Compton interactions, and produce relatively high energy secondary electrons. (wikipedia.org)
  • Fast neutron therapy has been applied successfully against salivary gland tumors.Adenoid cystic carcinomas have also been treated. (wikipedia.org)
  • Because fast neutrons have different radiobiological properties, certain tumors that are resistant to standard radiation respond better to neutrons. (uwmedicine.org)
  • Confined interlayer water in tungsten oxide hydrates (WO3·nH2O) stabilizes the layered structure, which explains the fast electrochemical proton intercalation found in these materials. (ornl.gov)
  • For delayed coincidence timing of the capture of fast neutrons, the time delay from the prompt recoil-proton pulse is typically 2.7µs for 5% B-nat plastics. (scribd.com)
  • How many protons, neutrons and electrons does oxygen have? (reference.com)
  • Lithium, a member of the alkali metals, has three protons, three electrons and four neutrons. (reference.com)
  • The three parts of an atom are the protons, neutrons and electrons. (reference.com)
  • The effectiveness of the technology will be demonstrated by neutron radiographic imaging of various test phantoms. (sbir.gov)
  • Other designs use different moderators, like heavy water, that are much less likely to absorb neutrons, allowing them to run on unenriched fuel. (wikipedia.org)
  • The neutron strikes producing tritium gas bubbles. (fusor.net)