The Spectral Distribution of the Radiation from a Microfocus X-Ray Tube with a Membrane Target

Abstract

The photon spectra for a massive and a membrane target of Al or Cu were compared, in terms of the pulse-height distribution obtained from a scintillation spectrometer, for accelerating voltages from 14.3 to 36.8 kv. The agreement within the limits of error, of the pulse-height distribution for a massive with that for a membrane target of A, leads to the conclusion that the photon spectra are identical, contrary to the results of Bessen (1957). Small systematic deviations in the case of Cu are attributed to differential absorption in the target. Measurements were also made of the dependence on accelerating voltage of the portion of characteristic radiation in the total X-ray output and of the signal-to-background ratio in a 90% channel for CuKα photons when the radiation is nickel-filtered.