A STUDY OF PROTON-INDUCED L-SHELL CROSS SECTIONS

Abstract

As a part of an effort to build up a reliable database for particle induced L shell cross sections, a study of the L-shell cross sections induced by proton impact was performed. A new compilation of the experimentally measured L-shell cross sections reported in the period from 1982 to 1993 was carried out. Based on data from old and new compilations, an overview of the current status experimental L-shell cross sections was presented. A qualitative comparison of the experimental L? x-ray production cross sections with the theoretically predicted values was also made. A few areas for further work have been identified. In an attempt to check the validity of the ECPSSR theory, a quantitative comparison between the experimental L-subshell ionization cross sections and ECPSSR predictions was carried out. Systematic deviation between the experimental values and the theoretical values was found in the case of L2 and L1 subshell ionization cross sections. For L1 subshell ionization cross sections, the fluctuation among experimental data was found to be too large for drawing any definite conclusion. New parameters for the calculation of L-subshell ionization cross sections using a semiempirical expression were obtained. The parameters were derived by fitting an analytical function to the experimental L-subshell ionization cross sections. A series of experiments were also carried out to measure the proton-induced L x-ray production cross sections of 8 medium Z elements. The effort has contributed a total of 345 data to this Z range where the amount of data is relatively scanty compared to other Z ranges.