Automatic exposure control: Automatic Exposure Control (AEC) is an X-ray exposure termination device. A medical radiography x-ray exposure is always initiated by a human operator.Samarium(III) chlorideRadiation protection of patients: Patients are exposed to ionizing radiations when they undergo diagnostic examinations using x-rays or radiopharmaceuticals, therapy of cancer or benign lesions using radiations emitted by radioisotopes or those by radiation generators; and in interventional procedures using fluoroscopy. There has been a tremendous increase in the use of ionizing radiation in medicine during recent decades.Radiation oncologist: A radiation oncologist is a specialist physician who uses ionizing radiation (such as megavoltage X-rays or radionuclides) in the treatment of cancer. Radiation oncology is one of the three primary specialties, the other two being surgical and medical oncology, involved in the treatment of cancer.Copy number analysis: Copy number analysis usually refers to the process of analyzing data produced by a test for DNA copy number variation in patient's sample. Such analysis helps detect chromosomal copy number variation that may cause or may increase risks of various critical disorders.Skewed X-inactivation: Skewed X chromosome inactivation occurs when the inactivation of one X chromosome is favored over the other, leading to an uneven number of cells with each chromosome inactivated. It is usually defined as one allele being found on the active X chromosome in over 75% of cells, and extreme skewing is when over 90% of cells have inactivated the same X chromosome.Ultra-high-energy cosmic ray: In astroparticle physics, an ultra-high-energy cosmic ray (UHECR) is a cosmic ray particle with a kinetic energy greater than eV, far beyond both its rest mass and energies typical of other cosmic ray particles.Radiation-induced lung injuryGamma counter: A gamma counter is a machine to measure gamma radiation emitted by a radionuclide. A large number of samples are placed in sealed vials or test tubes, and move along a serpentine track on a horizontal plane.Spaceflight radiation carcinogenesisRadiation-induced cancer: Up to 10% of invasive cancers are related to radiation exposure, including both ionizing radiation and non-ionizing radiation. Additionally, the vast majority of non-invasive cancers are non-melanoma skin cancers caused by non-ionizing ultraviolet radiation.External beam radiotherapyIrradiance: In radiometry (measurement of electromagnetic radiation), irradiance is the radiant flux (power) received by a surface per unit area, and spectral irradiance is the irradiance of a surface per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength. The SI unit of irradiance is the watt per square metre (), while that of spectral irradiance is the watt per square metre per hertz (W·m−2·Hz−1) or the watt per square metre per metre (W·m−3)—commonly the watt per square metre per nanometre ().UVB-induced apoptosis: UVB-induced apoptosis is the programmed cell death of cells that become damaged by ultraviolet rays. This is notable in skin cells, to prevent melanoma.Abscopal effect: The abscopal effect is a phenomenon in the treatment of metastatic cancer where localized treatment of a tumor causes not only a shrinking of the treated tumor but also a shrinking of tumors in different compartments from the treated tumor. Initially associated with single-tumor, localized radiation therapy, the term has also come to encompass other types of localized treatments such as electroporation and intra-tumoral injection of therapeutics.Radiosensitizer: A radiosensitizer is a drug that makes tumor cells more sensitive to radiation therapy.Chronic radiation syndrome: Chronic radiation syndrome is a constellation of health effects that occur after months or years of chronic exposure to high amounts of ionizing radiation. Chronic radiation syndrome develops with a speed and severity proportional to the radiation dose received, i.Cobalt-60List of nuclear and radiation accidents by death toll: There have been more than 20 nuclear and radiation accidents involving fatalities. These involved nuclear power plant accidents, nuclear submarine accidents, radiotherapy accidents and other mishaps.