Key experimental M subshell line x-ray production cross sections for slow light ions on high atomic number targets compared with the ECUSAR theory

Abstract

The x-ray production cross sections for dominant lines in each of the five M subshells have been measured for slow proton and helium ion impact on selected high atomic number targets from tungsten to uranium. Proton energies between 0.5 and 3 MeV and helium ion energies between 0.5 and 2 MeV were used providing M subshell cross sections for 0.3 < x < 3, where x = v /(q v ), as defined by Brandt and Mi s 1 s 2s Lapicki 1979, distinguishes between slow (x < 1) and fast (x > 1) collision regimes. s s Ion energies and targets over these ranges cover the commonly used PIXE range for M subshell x-ray production on heavy targets across the x-ray energy range 1.3-6 keV, which has a strong overlap with key common K shell elements from Al to Fe. Hence it is important for frequently used PIXE analysis programs like GUPIX and GEOPIXE to have a consistent set of M subshell cross sections together with subshell parameters, like fluorescence yields and Coster-Kronig transition rates, which will precisely and accurately predict M shell line intensities over this low energy X-ray region of interest.