X-ray Spectrum from a Beryllium Window Tube: II. Laplace Transformation

The X-ray spectra from two types of commercial Be-window tubes were analysed from attenuation data by means of the Laplace transformation. One tube was operated at 50 kV constant potential and the attenuation curves were obtained with a free-air standard ionization chamber, while the other tube was operated at 50 kVp pulsating potential and the attenuation curves were obtained with a Nal(Tl) scintillation spectrometer. In the first case, the spectrum by transform was compared with theory, while in the second case, the spectrum by transform was compared with the spectrum measured with the scintillation spectrometer. The percentage contribution of the characteristic radiation p = 0·65 in terms of ionization intensity for the constant potential case and p = 0·40 in terms of energy for the pulsating potential case.