CALCULATION OF CHARACTERISTIC X-RAYS IN DIAGNOSTIC-X-RAY SPECTRUM

We examined the experimental data of Fewell et al. [Handbook of Computed Tomography X-Ray Spectra (HHS Publication, Rockville, 1981) No. 81-8162], which exhibited the variation of the characteristic radiation yield with the beam angle, but did not confirm any model proposed by previous workers to explain its variation. We developed a new method of calculating the intensity of the characteristic radiation for the X-ray tube used in medical diagnosis. Our method was based on the photoelectric interactions of the bremsstrahlung photons with the target material, where the bremsstrahlung spectra used were calculated taking into account the electron energy distributions in a target material described in our previous paper. Our method did not include any adjustment parameters to fit with experimental data. Our calculated results are in good agreement with the experimental results of Fewell et al. In particular, the dependence of the intensity of the characteristic radiation on the beam angle, calculated using our method, agreed with the experiment results of Fewell et al., while the methods proposed by previous workers led to the reverse dependence.