Rays, cosmic gamma

Exposure to natural sources of radiation is unavoidable. Externally, individuals receive cosmic rays, terrestrial X-rays, and gamma radiation. Internally, naturally occurring radionuclides of Pb, Po, Bi, Ra, Rn, K, C, H, U, and Th contribute to the natural radiation dose from inhalation and ingestion. Potassium-40 is the most abundant radionuclide in foods and in all tissues. The mean effective human dose equivalent from natural radiations is 2.4 milliSieverts (mSv). This value includes the lung dose from radon daughter products and is about 20% higher than a 1982 estimate that did not take lung dose into account (Table 32.4). 

The American physicist Carl Anderson received his Ph.D. from the California Institute of Technology in 1930, after which he immediately set to work studying cosmic rays. Cosmic rays are not a kind of radiation like gamma rays. They are rapidly moving electrons and... 

In terms of what is measured or observed, there are (1) portions of the electromagnetic spectrum gamma-ray, cosmic ray, x-ray, ultraviolet, infrared, far-infrared, microwave, and radiowave instruments (2) regions pertaining to the energies of particles beta ray (electrons), protons, neutrons, and mass associated instruments and (3) instruments dealing with other spectra such as radioactive decay and Mossbauer effects. 

Now the penetrating power of the electrons knocked out of atoms by X-rays and gamma rays is very much smaller than that of the rays so that if cosmic rays were of the same nature as gamma rays—that is, if they were high energy photons—... 

Radio waves Infrared y Ultraviolet Gamma rays Cosmic rays... 

There are certain factors that affect the exposure and risk. These are the strengths of the source, type of radiation, and the distance. The energy order with respect to decreasing hazards is cosmic, gamma. X-rays > beta > a-particles. 

Stecker, F.W. (1971). Cosmic Gamma Rays (NASA Scientific and Technical Information Office, NASA SP-249). 

Keywords gamma rays, cosmic rays, supernova remnant... 

Oamma-ray spectrometers have been successfully used in the exploration of the lunar and Martian surfaces, and a gamma-ray spectrometer was a significant component of the Mars Surveyor mission. Its goals were to quantitatively determine elemental abundances on the Martian surface, to map the distribution of water, to study the seasonal polar caps, and to investigate the nature of cosmic gamma-ray bursts. 

Cheng, K. S., and G. V. Romero. Cosmic Gamma-Ray Sources. New York Springer-Verlag, 2004. 

Upper level discriminator (ULD) - pulses above this level will not be analysed. Use this to reject very high-energy pulses. This will often be left at its maximum, but still performs a useful function in rejecting high-energy cosmic gamma-rays. 

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