• The standard view of gamma-ray bursts as a signature for different types of dying stars might need a rewrite. (scitechdaily.com)
  • Astronomers have long believed that gamma-ray bursts fell into two categories: long-duration bursts from imploding stars and short-duration bursts from merging compact stellar objects," said Chris Fryer, an astrophysicist and Laboratory Fellow at the U. S. Department of Energy's Los Alamos National Laboratory . (scitechdaily.com)
  • Gamma-ray bursts can accompany both types of transients. (scitechdaily.com)
  • only a small subset of supernovae arise from the explosion mechanism that produces gamma-ray bursts. (scitechdaily.com)
  • This detection breaks our standard idea of gamma-ray bursts," said Eve Chase, also a coauthor of the paper, a postdoc at Los Alamos and a member of the Los Alamos team. (scitechdaily.com)
  • We can no longer assume that all short-duration bursts come from neutron-star mergers, while long-duration bursts come from supernovae. (scitechdaily.com)
  • We now realize that gamma-ray bursts are much harder to classify. (scitechdaily.com)
  • This detection pushes our understanding of gamma-ray bursts to the limits. (scitechdaily.com)
  • Under this paradigm, merging compact objects, with their halos of gravitationally attracted material (accretion disks), would produce short-duration gamma-ray bursts. (scitechdaily.com)
  • A new analysis of four extremely bright bursts observed by NASA's Fermi satellite suggests that the remnant from a long-duration gamma-ray burst is most likely a black hole - not a rapidly spinning, highly magnetized neutron star, or magnetar since such a burst emits more energy than is theoretically possible from a magnetar. (berkeley.edu)
  • Cenko will present these findings on Wednesday, Nov. 3, at the Nov. 1-4 Gamma Ray Bursts 2010 conference in Annapolis, Md. Cenko is a member of an international team that includes astronomers from UC Berkeley and the National Radio Astronomy Observatory (NRAO) in New Mexico. (berkeley.edu)
  • Long-duration gamma-ray bursts (GRBs) are presumed to be created by the explosive collapse in distant galaxies of massive stars. (berkeley.edu)
  • First discovered in 1967 by satellites looking for nuclear blasts on Earth, gamma-ray bursts have been the focus of several satellite missions, most recently NASA's Fermi gamma-ray space telescope, launched in 2008, and NASA's Swift satellite, launched in 2004. (berkeley.edu)
  • Fermi's Large Area Telescope, however, is sensitive to very bright bursts with jet breaks within several days of the burst, making follow-up observations easier with Swift's X-ray and ultraviolet-optical telescopes and the ground-based Very Large Array, a radio telescope operated by NRAO. (berkeley.edu)
  • A new generation of gamma-ray detectors, and subthreshold searches in existing detectors, will be essential to detect similar short bursts at greater distances. (edu.au)
  • formerly GLAST Burst Monitor), is being used to study gamma-ray bursts and solar flares. (wikipedia.org)
  • The GBM consists of 14 scintillation detectors (twelve sodium iodide crystals for the 8 keV to 1 MeV range and two bismuth germanate crystals with sensitivity from 150 keV to 30 MeV), and can detect gamma-ray bursts in that energy range across the whole of the sky not occluded by the Earth. (wikipedia.org)
  • Determine the high-energy behavior of gamma-ray bursts and transients. (wikipedia.org)
  • Gamma-ray bursts Study gamma-ray bursts with an energy range several times more intense than ever before so that scientists may be able to understand them better. (wikipedia.org)
  • Astronomers eventually realized these explosions were coming from deep space-not the Soviet Union-and named them gamma-ray bursts, or GRBs. (symmetrymagazine.org)
  • In the 1990s, observatories in space detected bursts of gamma rays coming from Earth that eventually were traced to thunderclouds. (symmetrymagazine.org)
  • Gamma Ray Bursts - The Most Powerful Objects in the Universe? (windows2universe.org)
  • They found bursts of Gamma Rays coming from outer space! (windows2universe.org)
  • It has been suggested that gamma rays coming from the dense region of space in the inner Milky Way galaxy could be caused when invisible dark matter particles collide, but two new studies suggest that the gamma ray bursts are due to other astrophysical phenomena such as fast-rotating stars called millisecond pulsars. (astronomynow.com)
  • The association of GW170817 and GRB 170817A provides new insight into fundamental physics and the origin of short gamma-ray bursts. (mendeley.com)
  • Hattori, M & Terasawa, N 1993, On the halo neutron star origin of the gamma-ray bursts: Origin of the halo neutron stars and metal enrichment of the intracluster medium . (elsevierpure.com)
  • Once the data looked straightforward, at least in terms of bursts of gamma rays from outer space. (theregister.com)
  • In an accompanying article , Luigi Piro, professor at Italy's National Astrophysics Institute, explained: "Over the past 25 years, astronomers have studied emissions at wavelengths longer than gamma-rays to pinpoint the source of these bursts, and have deduced that the two classes of burst come from distinct progenitor systems. (theregister.com)
  • Long γ-ray bursts take place in galaxies with irregular or spiral-shaped geometries, occurring preferentially in bright star-forming regions in the central part of the galaxy. (theregister.com)
  • The spectra of these bursts contain features consistent with supernovae, which are considered indisputable proof of the connection between long γ-ray bursts and the collapse of massive stars. (theregister.com)
  • By contrast, short γ-ray bursts can come from both spiral-shaped galaxies and more-regular elliptical galaxies, but always originate in isolated regions that are often far from the centres of their host galaxies. (theregister.com)
  • Then came along evidence of long-gamma ray bursts with no evidence of collapsing stars or supernovas. (theregister.com)
  • With the help of the information from gravitational wave detectors, astrophysicists have been able to present "indisputable evidence" that these anomalous long bursts of gamma rays are also connected to mergers of compact objects such as neutron stars, overturning years of established thinking in astrophysics. (theregister.com)
  • Alessio Mei, PhD student at Gran Sasso Science Institute in L'Aquila, Italy, also showed that the third class of gamma ray bursts also emit more high-energy photons than expected in the gigaelectronvolt range, whereas previously, the only known electromagnetic signature of a kilonova was the optical infrared flash. (theregister.com)
  • They could uncover hundreds of neutron-star mergers, about 1 in 10 of which could be associated with "the strange hybrid γ-ray bursts reported in the four papers. (theregister.com)
  • Gamma-ray bursts are the brightest known electromagnetic events in the universe, and can be created by a few different phenomena . (space.com)
  • Scientists observing a curious neutron star in a binary system known as the 'Rapid Burster' may have solved a forty-year-old mystery surrounding its puzzling X-ray bursts. (scitechdaily.com)
  • Scientists can account for these 'type-I' bursts, in terms of nuclear reactions that are ignited in the inflowing gas - mainly hydrogen - when it accumulates on the neutron star's surface. (scitechdaily.com)
  • But the Rapid Burster is a peculiar source: at its brightest, it does emit these type-I flashes, while during periods of lower X-ray emission, it exhibits the much more elusive 'type-II' bursts - these are sudden, erratic, and extremely intense releases of X-rays. (scitechdaily.com)
  • The neutron star binary system MXB 1730-335, also known as the 'Rapid Burster', is a peculiar X-ray source, one of only two known to exhibit the elusive 'type-II' bursts. (scitechdaily.com)
  • These bursts are sudden, erratic and extremely intense releases of X-rays that liberate enormous amounts of energy during periods otherwise characterized by very little emission occurring. (scitechdaily.com)
  • The gas then hits the neutron star all at once, giving rise to the dramatic emission of type-II bursts. (scitechdaily.com)
  • In contrast to type-I bursts, which do not represent a significant release of energy with respect to what is normally emitted by the accreting neutron star, bursts of type-II liberate enormous amounts of energy during periods otherwise characterized by very little emission occurring. (scitechdaily.com)
  • Known as the Bursting Pulsar and discovered in the 1990s, this binary system comprises a low-mass star and a highly magnetized, spinning neutron star - a pulsar - that exhibits only type-II bursts. (scitechdaily.com)
  • Today we know GRBs come in two types: the explosions of extremely massive stars, which pump out gamma rays as they die, and collisions between highly dense relics of stars called neutron stars and something else, probably another neutron star or a black hole. (symmetrymagazine.org)
  • They have also studied how these particles generate gamma rays and other emissions. (berkeley.edu)
  • Even with the addition of the misclassified gamma-rays, the PSD is effective in separating particles so that neutron count rate can be predicted with less than 10% error up to a gamma-to-neutron ratio of almost 650. (psu.edu)
  • For applications which can afford a reduction in neutron detection efficiency, PSD can be sufficiently effective in discriminating particles to measure a weak neutron source in a high gamma-ray background. (psu.edu)
  • The Higgs boson, for example, can decay into many different types of particles, including gamma rays. (symmetrymagazine.org)
  • Gamma rays could also be telltale signs of dark matter particles - hypothetical components of invisible dark matter, which accounts for 85 percent of all matter in the universe. (astronomynow.com)
  • As the black hole devours matter from its surroundings, it ejects jets of charged particles traveling almost as fast as light into space, generating beams of gamma rays in the process. (astronomynow.com)
  • Theories predict that the hypothetical particles would produce gamma rays when they decay or collide and destroy each other. (astronomynow.com)
  • Like many other subatomic particles, the neutron doesn't last long outside of the nucleus. (energy.gov)
  • The neutron is a useful guide to understanding other particles. (energy.gov)
  • They achieve stability through changes in the nucleus (spontaneous fission, emission of alpha particles, or conversion of neutrons to protons or the reverse). (cdc.gov)
  • This process is called radioactive decay or transformation, and often is followed by the release of ionizing radiation (beta particles, neutrons, or gamma rays). (cdc.gov)
  • Alpha particles are charged particles made up of 2 protons and 2 neutrons-essentially the nucleus of a helium atom. (medscape.com)
  • Heisenberg proposed a neutron-proton interaction which, besides from a phenomeno- logical spatial part, also depends on spin and isospin of the two particles. (lu.se)
  • For example, beta particles, gamma rays, and x-rays have a RWF of 1.0, making their effects on tissue largely equivalent. (medscape.com)
  • Alpha particles, however, have a RWF of 20, which indicates a biologic effect that is potentially 20 times greater than that of beta particles, gamma rays, or x-rays. (medscape.com)
  • Moreover, by combining chemical-vapor-deposited diamond and the hybrid detectors' ASIC, a fast neutron measurement is also possible in harsh environments. (iter.org)
  • The fast neutron removal cross sections were computed by the partial density method. (tci-thaijo.org)
  • We thereby demonstrate for the first time a real-time user experience to display fast neutron or gamma ray images from various radioactive sources set around the detector. (bvsalud.org)
  • In both cases, material from the star falls inward and is catapulted out by the spinning neutron star or black hole. (berkeley.edu)
  • GW170817 refers to the gravitational waves observed from the merger, while GRB 170817A looks at the gamma-ray burst produced by the neutron-star merger. (space.com)
  • Recent astronomical observations, supported by theoretical modeling, reveal a new observational fingerprint of neutron-star mergers, which may shed light on the production of heavy elements throughout the universe. (scitechdaily.com)
  • Typically, the gamma-ray burst itself lasts from a few seconds to as long as 100 seconds, but the afterglow, produced when the jets interact with gas and dust surrounding the star, emits visible light for a couple of weeks and radio radiation for several months. (berkeley.edu)
  • Search for evaporating primordial micro black holes (MBH) from their presumed gamma burst signatures (Hawking Radiation component). (wikipedia.org)
  • To monitor nuclear tests in the 1960s, the United States launched gamma radiation detectors on satellites. (symmetrymagazine.org)
  • The LAT has already collected hundreds of times more gamma rays than the previous-generation EGRET instrument on NASA's Compton Gamma-ray Observatory - an advance that has tremendously deepened insights into the production of this energetic radiation. (astronomynow.com)
  • 2012). Gamma-ray shieldingandstructuralpropertiesof barium-bismuth-borosilicateglasses.Radiation Physics and Chemistry, 81, 85-790. (tci-thaijo.org)
  • The timing and strength of the electromagnetic radiation at different wavelengths provided scientists with clues about the nature of the phenomena created by the initial neutron-star collision. (sciencedaily.com)
  • Absorption Coefficient -- Fractional decrease in the intensity of an unscattered beam of x or gamma radiation per unit thickness (linear absorption coefficient), per unit mass (mass absorption coefficient), or per atom (atomic absorption coefficient) of absorber, due to deposition of energy in the absorber. (cdc.gov)
  • Linear Absorption Coefficient -- A factor expressing the fraction of a beam of x or gamma radiation absorbed in a unit thickness of material. (cdc.gov)
  • their energy, including rest energy, being converted into electromagnetic radiation (called annihilation radiation) with two 0.51 Mev gamma photons emitted at an angle of 180° to each other. (cdc.gov)
  • Effect of an optimized X-ray blanket design on operator radiation dose in cardiac catheterization based on real-world angiography. (uib.no)
  • Ionizing radiation is emitted by radioactive elements and by equipment such as x-ray and radiation therapy machines. (msdmanuals.com)
  • Most diagnostic tests that use ionizing radiation (eg, x-rays, CT, radionuclide scanning) expose patients to relatively low doses of radiation that are generally considered safe. (msdmanuals.com)
  • The equivalent dose is the absorbed dose multiplied by a radiation weighting factor that adjusts for tissue effects based on the type of radiation delivered (eg, x-rays, gamma rays, electrons). (msdmanuals.com)
  • For x-rays, including CT, the radiation weighting factor is 1. (msdmanuals.com)
  • Herein, we demonstrate real-time visualization of gamma ray and neutron radiation detector data in MR using the Microsoft HoloLens 2 smart glasses, significantly reducing user interpretation burden. (bvsalud.org)
  • Radiation imaging systems typically use double-scatter events of gamma rays or fast neutrons to reconstruct the incidence directional information, thus enabling source localization. (bvsalud.org)
  • There are different kinds of ionizing radiation, such as alpha, beta and gamma rays and neutrons. (who.int)
  • The use of ionizing radiation in medicine began with the discovery of x-rays by Roentgen in 1895. (medscape.com)
  • Ionizing radiation can exist in 2 forms: as an electromagnetic wave, such as an x-ray or gamma ray, or as a particle, in the form of an alpha or beta particle, neutron, or proton. (medscape.com)
  • Interaction of a high-intensity optical laser beam with a solid target can generate `hot' electrons, which generate radiation hazards (mainly bremsstrahlung photons and neutrons) from interaction of hot electrons with target and the surrounding materials. (lu.se)
  • The experiment chamber is flooded with electromagnetic radiation up to gamma rays (from scattering of the high energy electrons). (lu.se)
  • But high-energy astrophysics also gives us important information about our own galaxy the Milky Way, neutron stars, supernovae, and stars like out own Sun, which emit a lot of high-energy radiation. (lu.se)
  • The surrogate reaction technique is in active use to indirectly determine radiative neutron capture cross sections for unstable nuclei. (go.jp)
  • Today we know alpha rays are the same thing as helium nuclei (two protons and two neutrons), beta rays are either electrons or positrons (their antimatter versions), and gamma rays are a kind of light. (symmetrymagazine.org)
  • [a] One of its isotopes, 270 Hs, has magic numbers of both protons and neutrons for deformed nuclei, which gives it greater stability against spontaneous fission . (wikipedia.org)
  • This decreased the number of neutron ejections during synthesis, creating heavier, more stable resulting nuclei. (wikipedia.org)
  • Two nuclei fuse into one, emitting a neutron . (wikipedia.org)
  • The nuclear equation of state (EOS) describes dense matter probed in terrestrial experiments with atomic nuclei as well as in astrophysical observations of neutron stars. (nature.com)
  • Especially interesting to study are pairs of mirror nuclei, which have the number of protons and neutrons interchanged. (lu.se)
  • In the few seconds after protons and neutrons formed but before they joined together into elements, there was a precise bit of timing. (energy.gov)
  • At a certain point, it got cool enough that protons and neutrons almost instantaneously joined to form helium and hydrogen . (energy.gov)
  • Gravitational Waves and Gamma-Ray. (mendeley.com)
  • The gravitational waves were followed by outbursts of gamma rays, X-rays, and visible light from the event. (sciencedaily.com)
  • The eruption of light and gravitational waves ( ripples in the universal fabric known as space-time) was produced by an event known as a kilonova, or the collision and merger of two neutron stars, which are the dead cores of stars that stopped burning fuel. (space.com)
  • Gravitational waves, first detected by LIGO in 2015, are produced by the acceleration of gigantic objects in the universe (such as colliding black holes or neutron stars). (space.com)
  • The triple GEM detector is an outstanding candidate for detecting plasma volumes emitting X-ray photons in the 2-30 keV energy range, thanks to its high dynamic range, sensitivity, high rate, energy resolution, and noise-free detection. (iter.org)
  • 2013).Investigation of X-and gamma ray photons buildup in some neutronshielding materials using GP fitting approximation. (tci-thaijo.org)
  • In nine years in space, the LAT has discovered more than 200 pulsars - rapidly spinning, very dense and highly magnetized neutron stars that emit "beams" of gamma rays like cosmic lighthouses. (astronomynow.com)
  • However, our knowledge about dense matter explored in the cores of neutron stars remains limited. (nature.com)
  • The nuclear EOS is governed by quantum chromodynamics (QCD), the theory of strong interactions, but direct calculations of dense matter in neutron stars based on QCD are not feasible at present. (nature.com)
  • A very promising tool is the multi-messenger astrophysics analysis of neutron stars and their collisions, which provides access to dense neutron-rich matter not accessible in terrestrial experiments at present. (nature.com)
  • Neutron stars are the leftover, dense cores of larger stars that ended their lives in supernova explosions. (space.com)
  • As neutron stars collide, some of the debris blasts away in particle jets moving at nearly the speed of light, producing a brief burst of gamma rays. (scitechdaily.com)
  • Modeling calls into question supernova origin, forcing a reconsideration of the prevailing view of gamma-ray-burst events. (scitechdaily.com)
  • But in a recently observed event, we've found a kilonova along with a long-duration gamma-ray burst, and that has thrown a wrench into this simple picture. (scitechdaily.com)
  • A recently observed gamma-ray burst looked like the emissions from a supernova but turned out to signal a previously undetected hybrid event involving a kilonova. (scitechdaily.com)
  • On December 11, 2021, several observatories and satellites recorded a very bright, 50-second gamma-ray burst and optical, infrared, and x-ray emissions associated with the burst. (scitechdaily.com)
  • Instead, the evidence pointed to a compact-object merger in a theorized but previously unobserved hybrid event that produces a kilonova but emits a long-duration gamma-ray burst. (scitechdaily.com)
  • Fryer and his Ph.D. advisor Stan Woosley coined and developed in 1999 the widely accepted black-hole accretion-disk paradigm as the simplest explanation for the two classes of gamma-ray-burst events. (scitechdaily.com)
  • A gamma-ray burst is an immensely powerful blast of high-energy light thought to be generated by a collapsing star in a distant galaxy, but what this collapse leaves behind has been a matter of debate. (berkeley.edu)
  • According to the theory of collapsars, a massive star collapses as its gas envelope forms a rotationally supported disk, often leading to the production of a relativistic jet that we observe as a gamma-ray burst. (berkeley.edu)
  • On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anti-Coincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory. (edu.au)
  • Finally, we predict a joint detection rate for the Fermi Gamma-ray Burst Monitor and the Advanced LIGO and Virgo detectors of 0.1-1.4 per year during the 2018-2019 observing run and 0.3-1.7 per year at design sensitivity. (edu.au)
  • Fermi includes two scientific instruments, the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). (wikipedia.org)
  • If one of the jets were pointed directly toward Earth, we would have seen a short-duration gamma-ray burst, like many seen before, the scientists said. (sciencedaily.com)
  • But in 2006, NASA's Neil Gehrels Swift observatory found a new kind of long gamma-ray burst with no evidence of a collapsing star. (theregister.com)
  • Before the burst, the fast-spinning magnetic field of the neutron star (blue arrow) keeps the gas (white arrows) flowing from the companion star at bay, preventing it from reaching closer to the neutron star and effectively creating an inner edge at the center of the disc. (scitechdaily.com)
  • Then, soon after the first burst was detected, the scientists set the other observatories into motion, using XMM-Newton to measure X-rays emitted directly by the neutron star's surface or by gas in the accretion disc, and NuSTAR to detect higher-energy X-rays, which are emitted by the neutron star and reflected off the disc. (scitechdaily.com)
  • The neutron is one of the building blocks of matter, the neutral counterpart to the positive proton. (energy.gov)
  • First application of a novel SRAM-based neutron detector for proton therapy. (uib.no)
  • A Monte Carlo feasibility study for neutron based real-time range verification in proton therapy. (uib.no)
  • Several quasiparticle alignments have been identified, involving neutron (h 11/2 ) 2 and proton (h 11/2 ) 2 aligned configurations. (lu.se)
  • In 1932 James Chadwick discovered the neutron [1, 2], which is the second building block of the atomic nucleus next to the proton. (lu.se)
  • Later the same year Werner Heisen- berg introduced the concept of isospin [3, 4, 5] which suggests that the neutron and proton can be described as two different states of the same particle, the nucleon. (lu.se)
  • This immediately implies that the nuclear force is charge indepen- dent and that the isospin symmetric neutron-neutron and proton-proton systems are synonymous. (lu.se)
  • The share of the background sources such as neutrons and gamma is obtained and the contribution that the experimental apparatus to the background, such as shielding, detector sleeve and moderator, is analyzed. (sinap.ac.cn)
  • The effective gamma signal (from soil and TNT) is 29% of the full spectrum signal, and the background signal, more than 68%, this is mainly produced by shielding and the detector sleeve. (sinap.ac.cn)
  • Instead an observatory like the Fermi Gamma-ray Space Telescope detects the signal from gamma rays when they hit a detector and convert into pairs of electrons and positrons. (symmetrymagazine.org)
  • Neutron stars, remnants of supernova explosions of massive stars, are among the most compact objects in our Universe. (mpg.de)
  • Interpreting high-energy, astrophysical phenomena, such as supernova explosions or neutron-star collisions, requires a robust understanding of matter at supranuclear densities. (nature.com)
  • Gamma-ray spectroscopy of neutron-rich 40S. (atomki.hu)
  • 0.1 MeV) at two temperatures (52 and 95 °C). The changes in the α-quartz phase as a function of these two conditions (temperature and fluence) were studied using X-ray powder diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM), and the results acquired using these complementary techniques are presented in a single place for the first time. (osti.gov)
  • In 2017, the gravitational-wave detectors caught the first signal from a binary neutron star merger and about 70 astronomical observatories on Earth and in space were involved in follow-up observations and investigated electromagnetic signals of this event. (mpg.de)
  • Data from the Very Large Array and other radio telescopes have allowed astronomers to identify the most likely scenario for the aftermath of the merger of two neutron stars. (sciencedaily.com)
  • On August 17, 2017, the LIGO and VIRGO gravitational-wave observatories combined to locate the faint ripples in spacetime caused by the merger of two superdense neutron stars. (sciencedaily.com)
  • The gradual brightening of the radio signal indicates we are seeing a wide-angle outflow of material, traveling at speeds comparable to the speed of light, from the neutron star merger," said Kunal Mooley, now a National Radio Astronomy Observatory (NRAO) Jansky Postdoctoral Fellow hosted by Caltech. (sciencedaily.com)
  • Soon after the initial observations of the merger site, the Earth's annual trip around the Sun placed the object too close to the Sun in the sky for X-ray and visible-light telescopes to observe. (sciencedaily.com)
  • The Fermi Gamma-ray Space Telescope (FGST, also FGRST), formerly called the Gamma-ray Large Area Space Telescope (GLAST), is a space observatory being used to perform gamma-ray astronomy observations from low Earth orbit. (wikipedia.org)
  • Fermi gained its new name in 2008: On 26 August 2008, GLAST was renamed the "Fermi Gamma-ray Space Telescope" in honor of Enrico Fermi, a pioneer in high-energy physics. (wikipedia.org)
  • This view shows the entire sky at energies greater than 1 GeV based on five years of data from the LAT instrument on NASA's Fermi Gamma-ray Space Telescope. (astronomynow.com)
  • NASA's Fermi Gamma-ray Space Telescope gives astrophysicists analogous powers. (astronomynow.com)
  • This means that it is possible to have a suitable attenuation of gamma ray and neutron beams in a single layer of concrete shield simultaneously. (cementwapnobeton.pl)
  • The WinXCom and NXcom programs were employed to calculate the attenuation coefficients of gamma-rays and neutrons, respectively. (ktu.edu.tr)
  • The main design parameter was the neutron attenuation factor. (energ-en.ro)
  • The use of passive gamma-ray and neutron detection and imaging technologies in security-sensitive areas and ports has had more impact than most other techniques in detecting and deterring illicit transportation and trafficking of illegal radioactive materials. (lancs.ac.uk)
  • GEANT4 Neutron induced Characteristic gamma-ray spectrum Background contribution I. INTRODUCTION 1 Research on explosives detection has gotten more attention around the world in terrorist activities in recent years. (sinap.ac.cn)
  • Radiative neutron capture cross section are of direct relevance for the synthesis of heavy elements referred to as the s-process and the r-process in nuclear astrophysics and constitute basic data in the field of nuclear engineering. (go.jp)
  • Resolve the gamma-ray sky: unidentified sources and diffuse emission. (wikipedia.org)
  • SF), a nuclear statistical quantity that interconnects photoneutron emission and radiative neutron capture in Hauser-Feshbach model calculation. (go.jp)
  • Based on the new simulations, Dietrich and his research group will model the gravitational-wave and electromagnetic emission from binary neutron star mergers with higher accuracy and connect theoretical computations with observational data. (mpg.de)
  • This model would explain the fact that the radio and X-ray emission were seen only some time after the collision. (sciencedaily.com)
  • That simple model -- of a jet with no structure (a so-called top-hat jet) seen off-axis -- would have the radio and X-ray emission slowly getting weaker. (sciencedaily.com)
  • Measuring neutrons in the presence of high gamma-ray fluence is a challenge with multi-particle detectors. (psu.edu)
  • That static electricity also acts like a giant particle accelerator, creating pairs of electrons and positrons, which then annihilate into gamma rays. (symmetrymagazine.org)
  • Since gamma rays are often produced in violent processes, their observation sheds light on extreme cosmic environments, such as powerful star explosions, high-speed particle jets spewed out by supermassive black holes, and ultradense neutron stars spinning unimaginably fast. (astronomynow.com)
  • More energetic than X-rays, they are born in the chaos of exploding stars, the annihilation of electrons and the decay of radioactive atoms. (symmetrymagazine.org)
  • A series of measurements was performed to investigate the gamma ray spectra, in the region from about 100 kev to about 3 Mev, resulting from the capture of thermal neutrons in a number of elements. (unt.edu)
  • 1.9 to 2.40 as the decomposition temperature is increased from 150 degree to l000 degree C. This change in refractive index parallels a gradual change in the x-ray diffraction pattern from weak, diffuse lines for PuO2 ignited at 150° to sharp, well resolved lines for PuO2 ignited at 1000°C. Similar results are observed for PuO2 made by thermal decomposition of Pu2(C2O4)3*11H2O. (unt.edu)
  • The traditional neutron activation analysis (NAA) [ 1 1 ] method has difficultly distinguished explosive and non-explosive organic materials because of the same components of C, H, N, and O. The pulsed fast/thermal neutron analysis (PFTNA) [ 2 2 ] technique can combine the prompt inelastic scattering gamma-ray spectrum of fast neutrons with the delayed radiative capture gamma-ray spectrum of thermal neutrons. (sinap.ac.cn)
  • The hybrid detectors can be coated with one (or more) layers of converter material to observe thermal neutrons. (iter.org)
  • Neutron stars Study younger, more energetic pulsars in the Milky Way than ever before so as to broaden our understanding of stars. (wikipedia.org)
  • Gamma rays are the most energetic type of light, packing a punch strong enough to pierce through metal or concrete barriers. (symmetrymagazine.org)
  • It captures images of the universe in gamma rays, the most energetic form of light. (astronomynow.com)
  • hot-blob-points-to-a-neutron-star-lurking-in-supernova-1987a https://www.astronomy.com/science/hot-blob-points-to-a-neutron-star-lurking-in-supernova-1987a/ Hot 'blob' points to a neutron star lurking in Supernova 1987A Astronomers have long suspected a city-sized neutron star hides within the dusty shroud of SN 1987A. (astronomy.com)
  • Astronomers have long suspected a city-sized neutron star hides within the dusty shroud of SN 1987A. (astronomy.com)
  • Astronomers have found new, compelling evidence that Supernova 1987A harbors a neutron star (blue-white) within a newly imaged 'blob' of extremely hot dust (red), as seen in this artist's concept. (astronomy.com)
  • For quite some time, astronomers have assumed SN 1987A initially left behind a neutron star. (astronomy.com)
  • But even though these neutrinos almost certainly came from the birth of a neutron star in SN 1987A, astronomers aren't sure whether that neutron star lives on, or rather quickly collapsed into a black hole. (astronomy.com)
  • In a new paper published July 30 in The Astrophysical Journal , astronomers report they've found compelling evidence that SN 1987a is still harboring a neutron star, which would make it the youngest such stellar corpse yet known. (astronomy.com)
  • Instead, the newly discovered blob seems to be a giant gas cloud that dramatically outshines its surroundings, and it's located right where astronomers think SN 1987A's neutron star should be. (astronomy.com)
  • To study gamma rays, astronomers build telescopes in space. (symmetrymagazine.org)
  • To see gamma rays before they reach the atmosphere, astronomers have to build telescopes in space. (symmetrymagazine.org)
  • Three months of observations with the National Science Foundation's Karl G. Jansky Very Large Array (VLA) have allowed astronomers to zero in on the most likely explanation for what happened in the aftermath of the violent collision of a pair of neutron stars in a galaxy 130 million light-years from Earth. (sciencedaily.com)
  • The observed measurements are helping the astronomers figure out the sequence of events triggered by the collision of the neutron stars. (sciencedaily.com)
  • Astronomers may have solved a 40-year-old mystery surrounding a neutron star in the "Rapid Burster" system. (scitechdaily.com)
  • Among the LAT discoveries are more than 200 pulsars - rapidly rotating, highly magnetized cores of collapsed stars that were up to 30 times more massive than the Sun. Before Fermi's launch, only seven of these objects were known to emit gamma rays. (astronomynow.com)
  • The LAT data have led us to totally revise our understanding of how pulsars emit gamma rays. (astronomynow.com)
  • We therefore confirm binary neutron star mergers as a progenitor of short GRBs. (edu.au)
  • These open questions of nuclear physics and cosmology can be answered with observations of various cosmic signals of merging binary neutron stars. (mpg.de)
  • Therefore, the ERC project will focus on developing new and more advanced models to interpret binary neutron-star coalescences. (mpg.de)
  • Discovered in the 1970s, the Rapid Burster is a binary system comprising a low-mass star in its prime and a neutron star - the compact remnant of a massive star's demise. (scitechdaily.com)
  • Probe dark matter (e.g. by looking for an excess of gamma rays from the center of the Milky Way) and early Universe. (wikipedia.org)
  • The background image shows the center of the Milky Way as seen by NASA's Chandra X-ray Observatory. (astronomynow.com)
  • At a galactic scale, such an ejection mechanism could have produced what is known as the Fermi bubbles - two giant areas above and below the center of the disk of our Milky Way galaxy that shine in gamma rays. (astronomynow.com)
  • The LAT has also shown for the first time that novae - thermonuclear explosions on the surface of stars that have accumulated material from neighboring stars - can emit gamma rays. (astronomynow.com)
  • When neutron stars merge, they can produce radioactive ejecta that powers a kilonova signal, as this conceptual image shows. (scitechdaily.com)
  • When two neutron stars merge, they can explode as a kilonova, as shown in this artist's impression . (space.com)
  • it may be thought of as a sequel to the EGRET instrument on the Compton Gamma Ray Observatory. (wikipedia.org)
  • Compton Gamma-Ray Observatory (pp. 1054-1058). (elsevierpure.com)
  • Some of the events we have been finding seem to be pushing right up against this total limit for a neutron star progenitor system," said S. Bradley Cenko, a post-doctoral fellow from the University of California, Berkeley. (berkeley.edu)
  • Long-duration GRBs (longer than two seconds) are typically associated with supernovae, while short-duration GRBs (less than two seconds) are commonly associated with neutron-star mergers. (scitechdaily.com)
  • Neutron-star mergers form some of the heaviest elements-those beyond iron on the periodic table. (scitechdaily.com)
  • We can measure all the light emitted - very high energy gamma rays, and, at later times, X-ray, optical and radio afterglow emissions - but that doesn't provide a very good estimate, because GRBs emit in relatively narrow jets. (berkeley.edu)
  • That's good for our health, but not so great for those who want to study GRBs and other sources of gamma rays. (symmetrymagazine.org)
  • To destroy brain cancers and other problems, medical scientists sometimes use a 'gamma ray knife. (symmetrymagazine.org)
  • Even though theory predicts that a Higgs boson will decay into gamma rays just 0.2 percent of the time, this type of decay is relatively easy to identify and it was one of the types that scientists observed when they first discovered the Higgs boson. (symmetrymagazine.org)
  • Scientists would like to have a solid number for the neutron lifetime to plug into these equations. (energy.gov)
  • But scientists can't put timers on neutrons to see how fast they fall apart. (energy.gov)
  • It could be revealing an unknown process in neutron decay. (energy.gov)
  • Instead, they find ways to measure neutrons before and after they decay to calculate the lifetime. (energy.gov)
  • Nuclear physicists first started studying the neutron lifetime because of its essential role in physics. (energy.gov)
  • The neutron stars collapsed into a remnant, possibly a black hole, whose powerful gravity began pulling material toward it. (sciencedaily.com)
  • Nuclear reactions are a major source of gamma rays. (symmetrymagazine.org)
  • Thus far, reactions that created new elements were similar, with the only possible difference that several singular neutrons sometimes were released, or none at all. (wikipedia.org)
  • The relative biological efficiency (RBE) of neutrons versus gamma rays varies inversely with neutron energy down to 0.4 MeV, where it can reach values of 20 and more. (who.int)
  • ComQum-UX or joint quantum neutron and X-ray refinement is a method to combine joint neutron and X-ray crystallographic refinement with QM/MM calculations to obtain an optimum compromise between neutron crystallography, X-ray crystallography and quantum chemistry. (lu.se)
  • By varying the distance from an EJ-309 scintillator to a strong-gamma-ray source and keeping a weak-neutron source at a fixed position, various gamma-to-neutron ratios can be measured and PSD performance can be quantified. (psu.edu)
  • As such, it provides a lot of insight into the weak force, the force that determines if neutrons turn into protons or not. (energy.gov)
  • The window to study these fascinating events has only recently been opened with the upgrades of the gravitational-wave observatories Advanced LIGO and Advanced Virgo and by combining gravitational-wave information with that of powerful telescopes in the electromagnetic spectrum - from infrared, to optical, to gamma-rays. (mpg.de)
  • Dozens of observatories detected the event using every wavelength of light, from radio waves to gamma-rays. (space.com)
  • Dietrich's research focuses on studying the collision of two neutron stars. (mpg.de)
  • The gap between our current knowledge of the EOS stemming from nuclear theory and experiment at low densities and astrophysical observations of neutron stars at higher densities can be bridged by heavy-ion collision (HIC) experiments. (nature.com)
  • The purpose of the experiment was to supplement the high energy capture gamma ray data in order to remove some of the ambiguities from the proposed energy level schemes and to obtain information for the Shielding Group of Brookhaven National Laboratory on elements normally found in reactors. (unt.edu)
  • This work combines nuclear theory, nuclear experiment and astrophysical observations, and shows how joint analyses can shed light on the properties of neutron-rich supranuclear matter over the density range probed in neutron stars. (nature.com)
  • However, these observations mainly probe the EOS at densities \(\gtrsim 2{n}_{{\rm{sat}}}\) and still carry considerable uncertainties, reflected in the ranges for predictions of neutron-star radii. (nature.com)
  • Prompt gamma-ray analysis was applied to determine hydrogen in geological samples. (elsevierpure.com)
  • Yamazaki, S, Oura, Y & Ebihara, M 2007, ' Determination of hydrogen in rock samples by neutron-induced prompt gamma-ray analysis ', Journal of Radioanalytical and Nuclear Chemistry , vol. 272, no. 2, pp. 353-357. (elsevierpure.com)
  • What is left behind is the collapsed core, a Neutron Star or sometimes a Black Hole . (windows2universe.org)