
Accession Number : ADA311135
Title : Absorption of gammaRays.
Corporate Author : TECHNICAL INFORMATION SERVICE (AEC) OAK RIDGE TN
Personal Author(s) : Snyder, W. S. ; Powell, J. L.
PDF Url : ADA311135
Report Date : 25 NOV 1949
Pagination or Media Count : 21
Abstract : In the evaluation of experiments on gamma ray attenuation and in the general problem of shield design it is necessary to have accurate knowledge of absorption coefficients as a function of gamma ray energy and of atomic number. Even a cursory examination of the literature reveals surprisingly large discrepancies among the values quoted by various authors, differences of five or ten percent of the total coefficient being not uncommon. An attempt is made here to compile a table of coefficients which is representative of the best experimental data available at the present time, and to give an estimate of the accuracy of the values given. Except for a quite limited range of the variables involved, it has been found that theoretical formulae, as given in standard textbooks, cannot in general be relied upon to give the absorption coefficients with an accuracy of five percent. This seems to be attributable, in most cases, to various approximations which enter the theoretical calculations of cross sections for photoelectric absorption and for pair production.
Descriptors : *ABSORPTION CROSS SECTIONS, *GAMMA RAY CROSS SECTIONS, EXPERIMENTAL DATA, COMPUTATIONS, THEORY, TABLES(DATA), ATTENUATION, VALUE, PAIR PRODUCTION, RADIATION SHIELDING, PHOTOELECTRICITY.
Subject Categories : Nuclear Physics & Elementary Particle Physics
Distribution Statement : APPROVED FOR PUBLIC RELEASE