L X-ray intensity ratios for high Z elements induced with X-ray tube

• Instead of radioactive source, we study the L X-ray intensity ratios by bremsstrahlung radiation.
• The ionization cross section of L3 subshell shows a larger increase than L1 and L2 subshells for Ta and W with the variation of excitation energy from 59.5 keV to 13.1 keV.

We have studied the intensity ratios I(Lα1,2)/I(Lβ1,2), I(Lα1,2)/I(Lγ) and I(Lβ1,2)/I(Lγ) for elements Ta, W, Au and Pb by 13.1 keV bremsstrahlung radiation. In this work, experimental values were compared with the theoretical results and other experimental results. Theoretical results of the intensity ratios were calculated with theoretical subshell photoionization cross sections, fractional X-ray emission rates, fluorescence yields, and Coster–Kronig transition probabilities. Good agreement can be observed between experimental values and theoretical results. Comparing with L1 and L2 subshells, the ionization cross section of L3 subshell shows a large increase for Ta and W with the variation of excitation energy from 59.5 keV to 13.1 keV.