DISINTEGRATION-RATE DETERMINATION BY 4π-COUNTING: PART V. FURTHER STUDIES ON ABSORPTION AND SCATTERING OF β-RADIATION

Abstract

The work of Pate and Yaffe on the study of absorption and scattering of β-radiation in a 4π-counter has been extended to greater source-mount thickness. As the thickness is increased, the backscattering curves assume the juxtaposition obtained in <2π geometrical systems. The saturation backscattering value S is attained at a mass approximately one-fifth that of the range of the β-radiation. The relationship S = 0.070 log10Emax + 0.142, where Emax is the maximum energy of the β-radiation, is obeyed over the range studied. The phenomenon of coincident discharges, while adequately explained by Pate and Yaffe as caused by wall- and gas-scattering if thin film source mounts are used, cannot completely account for the results with thicker films. Other phenomena, such as bremsstrahlung and secondary electron production, begin to play a role.