Influence of Coster-Kronig transitions on the polarization of L-shell x rays induced by proton impact

The alignment parameters for L-3-subshells of Cd and Sb atoms are obtained by measuring the degree of polarization of the L-1-lines excited by proton impact in the range from 0.1 to 0.5 MeV. To compare the experimental alignment parameter with theory, either experimental or numerical results must be corrected for Coster-Kronig (CK) transitions. The uncertainty in CK transition yields makes this comparison difficult. In this work, semiempirical values of the corrections have been derived from measured L-line intensities. The semiempirical correction factors exceed the theoretical ones. For constant reduced velocity, the semiempirical correction factor depends on the atomic number of the target. The semiempirical correction factor obtained in the same experiment improves the agreement between the theoretical alignment parameter and the experimental data. (C) 1998 American Institute of Physics.