Variation of enhancement effect of Coster-Kronig transition of L3 X-Rays of Ba, La and Ce compounds

The Coster-Kronig (CK) enhancement effect was measured for L₃ subshell X-rays using the experimental Lα X-ray production cross-section, the fraction of Lα X-rays, L₃ subshell fluorescence yields and L₃ subshell photoionisation cross-section. The samples were excited by gamma-rays with 59.5 keV energy from a 75 mCi radioisotope source and L X-rays emitted from samples were counted by a Si(Li) detector with resolution 155 eV at 5.96 keV. Variation of enhancement effect of CK transition of L₃ X-rays of La and Ce compounds was measured to be more than that of Ba. Ba has a partially filled 6s orbital whereas La and Ce have partially filled 5d and 4f orbitals, respectively.