Accession Number : AD0715271

Title :   Low-Energy Gamma Rays in the Atmosphere.

Descriptive Note : Special rept.,

Corporate Author : SMITHSONIAN ASTROPHYSICAL OBSERVATORY CAMBRIDGE MASS

Personal Author(s) : Pushkin,Jerome S.

Report Date : 30 JUN 1970

Pagination or Media Count : 114

Abstract : The low energy (0.3 - 10 Mev) gamma ray flux at balloon altitude (3.5mb) and at medium latitude (approx 42 degrees), resulting from energetic particle interactions with atmospheric atoms, is calculated from measured particle intensity vs. depth profiles. Electron bremstrahlung is found to be the dominant source of such photons, with a substantial contribution from positron annihilation gamma rays in the 0.3 - 0.51 Mev region. The intensity of low energy atmospheric photons is found to be strongest in the upwards and sidewards directions. The energy and angular response of a typical low energy detector - 3 inch x 3 inch NaI crystal - is investigated. Finally, the response of such a dector to the atmospheric flux calculated earlier is predicted and found to be in good agreement with experiment. (Author)

Descriptors :   (*ATMOSPHERES, GAMMA RAYS), (*COSMIC RAYS, NUCLEAR REACTIONS), ELECTRONS, INELASTIC SCATTERING, INTERACTIONS, BREMSSTRAHLUNG, POSITRONS, PHOTONS, MONTE CARLO METHOD, COMPUTER PROGRAMMING, BALLOONS, THESES

Subject Categories : Astrophysics
      Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE