Backscattering of Gamma Rays

Investigations of multiple backscattering and albedos of 1.12MeV gamma photons in elements and alloys

“…Bulatov and Garusov [3] used a small dosimeter without a collimator and calculated the energy albedos for gamma photons from 60 Co and 198 Au radioactive sources. Hyodo [4] used a small point isotropic source on the surface of a scatterer and a NaI(Tl) scintillator without a collimator, and calculated the number and energy albedos, and energy distributions of backscattered gamma photons from semi infinite slabs of paraffin, aluminium, iron, tin and lead. Along with the experiments [4], he has also applied successfully Monte Carlo method for the simulation of multiple backscattering of gamma photons in these materials.…”

“…Hyodo [4] used a small point isotropic source on the surface of a scatterer and a NaI(Tl) scintillator without a collimator, and calculated the number and energy albedos, and energy distributions of backscattered gamma photons from semi infinite slabs of paraffin, aluminium, iron, tin and lead. Along with the experiments [4], he has also applied successfully Monte Carlo method for the simulation of multiple backscattering of gamma photons in these materials. Hayward and Hubbell [5] developed a Monte Carlo method to determine the albedo factor at 1 MeV photons scattered from semi-infinite slabs of water, aluminium, copper, tin and lead at various angles of incidence.…”

Radial Distribution of Photons Backscattered from the Surface of Semi-Infinite Scatterer

“…(2) written by one of the authors (T.H.) , the radial distribution of photons backscattered in the direction perpendicular to the front face of a semi-infìnite scatterer was examined for the case of a point isotropic r-source placed on the scatterer.…”

“…Bulatov(3) has obtained the same formula for graphite scatterer, with 60Co r-rays. Davisson and Beach(4) have attempted to confìrm this formula by Monte Carlo calculations, and found that the number of photons backscattered at all angles from the front face of the scatterer decreases with distance by φ (r)=N T (l-ear ) ， (2) where φ (r) is the fraction of photons emerging from within a circle of radius r around the point source, and NT the total fraction of reflected photons, i.e. , the number albedo.…”

Radial Distribution of Photons Backscattered from the Surface of Semi-Infinite Scatterer

“…Bulatov(3) has obtained the same formula for graphite scatterer, with 60Co r-rays. Davisson and Beach(4) have attempted to confìrm this formula by Monte Carlo calculations, and found that the number of photons backscattered at all angles from the front face of the scatterer decreases with distance by φ (r)=N T (l-e-ar ) ， (2) where φ (r) is the fraction of photons emerging from within a circle of radius r around the point source, and NT the total fraction of reflected photons, i.e. , the number albedo.…”