The Continuous X-ray Spectrum from Electron-opaque Targets

Abstract

The angular and energy distributions of the continuous x-ray spectrum have been investigated in the forward hemisphere for accelerating potentials between 6 and 12 kv. The targets were sufficiently thick to bring the incident electrons to rest, and the spectral distributions closely resemble those obtained by earlier workers with massive targets. The angular distributions are greatly influenced by electron scattering, and it is shown that the degree of anisotropy is consistent with multiple scattering and diffusion being usually prevalent even when the electrons have lost only a small proportion of their incident energy. The absolute efficiency of x-ray production was found to be about 20% greater than expected from the formula of Compton and Allison. A proportional counter was used for the measurements, and the method is described.