Ionizing radiation cosmic

Anti-coincidence units are used to reduce the effects of external interferences. The detector is surrounded by a second guard detector, so that ionizing radiation from outside (e.g. cosmic rays) must active the outer detector before penetrating to the inner. A sample placed close to, or inside, the inner detector will activate that only. The anti-coincidence unit is arranged to accept only the latter noncoincident pulses from the measuring detector. 

The exposure to ionizing radiation from natural sources is continuous and unavoidable. For most individuals, this exposure exceeds that from all human-made sources combined (UNSCEAR 2000a). The two main contributors to natural radiation exposures are high-energy cosmic ray particles incident on the earth s atmosphere and radioactive nuclides that originate in the earth s crust and are present everywhere in the environment, including the human body itself. 

Ionizing radiation includes not only a particles, f3 particles, and y rays, but also X rays and cosmic rays. X rays, like y rays, are high-energy photons (A = 10—8—10—11 m) rather than particles cosmic rays are energetic particles coming from interstellar space. They consist primarily of protons, along with some a and j3 particles. 

Ionization radiation is common in our environment. Radiation sources for human exposure include radon, rocks, and soil in some areas, cosmic radiation and medical/... 

Mutagenesis can occur as the result of exposure to ionizing radiation and certain chemicals. Ionizing radiations include cosmic rays, x rays, and ultraviolet light. It is of interest to note that melanoma, caused almost exclusively by exposure to the ultraviolet radiation from the snn, is the most rapidly increasing lethal cancer in the United States. In melanoma, ultra violet radiation induces what is called thymine dimers. This means that two thymine nucleotides next to each other in a DNA sequence form an abnormal bond. Thymine dimers in a... 

Exposure to natural sources of external ionizing radiation results from the levels of cosmic and terrestrial X and gamma radiation present in the environment. Cosmic radiation at the earth s surface is affected by altitude, geomagnetic latitude, and solar modulation. For example, the dose rate at... 

Our bodies are subject to continuous attack by ionizing radiation from cosmic rays from outer space, from y-rays from the natural radionuclides in the upper layers of the Earth s crust, and a, P, and y-rays from the radionuclides, C, etc., that are naturally present in our... 

First, aerosol particles are important from the point of view of atmospheric electricity. A fraction of the air molecules is electrically charged (small ions), as a result of ionizing radiation. Measurements show (Bricard and Pradel, 1966) that in 1 cm3 of surface air about 10 ion-pairs are formed each second. Eight out of ten are produced by the radioactivity of the air and soil, while the other two are produced by cosmic radiation. The electrical properties of the air are determined by the electrical mobility (B) of ions formed ... 

The production of the hydrated electron by the interaction of ionizing radiation with water was one of the outstanding discoveries in chemistry in the 1960s. It thus became apparent that reactions of this species, produced as a result of cosmic bombardment of the earth s surface, must have been occurring from primeval times. It is, however, only relatively recently that it has been possible to study reactions of the hydrated electron in the laboratory. 

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