L shell ionizations of chlorine and argon by proton and alpha particle bombardments

The L Auger electron spectra have been observed for chlorine and argon bombarded with protons and alpha particles of 0.3-2.6 MeV in energy. The satellite lines, which are attributable to a simultaneous M shell ionization, have increased in comparison with the spectra obtained by electron impact. The numbers of created M shell vacancies of argon are estimated as 0.3 ± 0.1 and 1.1 ± 0.4 in average for protons and alpha particles at 1.8 MeV, respectively. The ionization cross sections for both projectiles have been compared with the theory of binary encounter approximation, resulting in a few tens percent reduction for argon and an overestimation for chlorine. The projectile z dependence of ionization cross section has been confirmed for chlorine and argon.