Cosmic ray origin

Reeves H, Fowler WA, Hoyle F (1970) Galactic cosmic ray origin of Li, Be and B in stars. Nature 226 727-729... 

A highly penetrating type of nuclear radiation similar to x-ray radiation, except that it comes from within the nucleus of an atom and has a higher energy. Energywise, very similar to cosmic ray except that cosmic rays originate from outer space. 

Dermer, C.D. (2004). Gamma ray bursts, sepemovae, and cosmic ray origin , in Proc. of ISCRA 13th Course, Eds. M. Shapiro, T. Stanev and J. Wefel, World Scientific Publ., p.189. 

In the meanwhile, significant progress in the phenomenological understanding of the arriving cosmic-ray intensity, and in the identification of the individual components was made. Nevertheless, it took until the late 1970 s before the currently accepted model of cosmic-ray origin was developed. This model reconciles the Baade/Zwicky and Fermi proposals by describing a first-order... 

It is concluded that the study of cosmic-ray origins remains a field in ferment, and the dust grains in superbubbles are just one of several scenarios under... 

Origin. Typical meteorites have formation ages of 4.55 Gyr and exposure ages of only 10 years, duting which time they existed as meter-sized bodies unshielded to the effects of cosmic rays. With the exception of the SNC (Martian) and lunar meteorites it is widely befleved that most conventional... 

Cosmic Rays—High-energy particulate and electromagnetic radiations which originate outside the earth s atmosphere. 

Cosmic rays Highly penetrating radiations that originate in outer space. 

The origin and cause of acceleration of cosmic rays is somewhat uncertain, but the power-law energy spectrum suggests some kind of electromagnetic process... 

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. 

The study of galactic cosmic rays is perhaps more an exercise in taste than in visual appreciation. In fact we determine their composition without ever really seeing them. However, they constitute the only sample of matter in our possession that comes from outside the Solar System. The chemical and isotopic composition of this sample is measured using balloon- or satellite-borne particle detectors, since the Earth s atmosphere is fatal to them. When they slam into nuclei in the air, they fragment into tiny particles, thereby losing their original identity. 

Since the production rates of the cosmic ray radionuclides increase rapidly with increasing altitude in the lower atmosphere, the atmospheric concentrations and ratios of short lived cosmic ray radionuclides can be used to study rapid vertical air motions if the equilibrium concentrations of the radionuclides are known. For example, the concentrations of the short lived cosmic ray radionuclides in air which has moved upward recently from a lower altitude will be less than the equilibrium concentrations. The concentrations of the radionuclides will therefore increase with time until equilibrium is reached. However, the concentration of the shorter lived of two short lived radionuclides will increase more rapidly initially, causing the ratio of the two radionuclides of different half-lives to change with time until equilibrium is reached. Therefore, the time since the air moved from a lower altitude, the speed of the upward motion, and the altitude from which the air originated could be calculated from the concentrations and concentration ratios of cosmic ray radionuclides of different half-lives. Vertical motions of different speeds could be studied since several cosmic ray radionuclides of different half-lives are present in the atmosphere (Table I). Many other radionuclides are produced by cosmic rays in the atmosphere, but they have not yet been detected. Some of these with half-lives of a few minutes could serve as tracers of very short term processes such as post-nucleation scavenging. 

CHEMICAL COMPOSITION OF HIGH-ENERGY COSMIC-RAY NUCLEI AND ITS POSSIBLE ORIGIN IN TYPE-II SUPERNOVA... 

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