Relative X-ray transition probabilities to the K-shell

Abstract

Accurate measurements over an extended range in Z have been made of the major K X-ray groups. Errors due to scattering and fluorescent excitation have been minimized by the use of carrier-free radioactive sources mounted on thin Mylar films, resulting in very high peak-to-continuum ratios. The measurements of K β K α , K α2 K α1 , K β′1 K α1 and K β′2 K α1 X-ray intensity ratios have been carried out to approximately 2% accuracy. For Z ≧ 38, a high-resolution Ge(Li) X-ray detector (460 eV FWHM at 6.4 keV) was used; at low Z, a Si(Li) X-ray detector (260 eV FWHM at 6.4 keV and a 0.05 mm Be window) was used. The low-energy efficiency of each detector was evaluated with corrections applied for deadlayer absorptions, K X-ray escape, energy-dependent geometry, and detector shape and mounting. The results are compared with recent relativistic theoretical calculations by Scofield.