<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>L</mml:mi></mml:math>-subshell ionization by proton and alpha-particle bombardment of Ta, Au, and Bi

Abstract

Cross sections for ionization of the ${L}_{\mathrm{I}}$, ${L}_{\mathrm{II}}$, and ${L}_{\mathrm{III}}$ subshells in Ta, Au, and Bi have been measured for proton energies from 1.0 to 5.5 MeV and $\ensuremath{\alpha}$-particle energies from 1.0 to 11.0 MeV. X-ray spectra recorded with a Si(Li) detector were used to deduce the subshell ionization cross sections: $L\ensuremath{\alpha}$ components give ${L}_{\mathrm{III}}$ subshell ionization cross sections ${\ensuremath{\sigma}}_{{L}_{3}}$, and $L\ensuremath{\gamma}$ components were computer analyzed into $L{\ensuremath{\gamma}}_{5}$, $L{\ensuremath{\gamma}}_{1}$, $L{\ensuremath{\gamma}}_{2+3}$, and $L{\ensuremath{\gamma}}_{4}$ to give the ${L}_{\mathrm{II}}$ and ${L}_{\mathrm{I}}$ subshell ionization cross sections, ${\ensuremath{\sigma}}_{{L}_{2}}$ and ${\ensuremath{\sigma}}_{{L}_{1}}$, respectively. The data are compared with simple model calculations. The necessity of including some small but significant additional effects in the plane-wave Born-approximation treatment, particularly wave functions more realistic than the normally assumed hydrogenic forms, is discussed.