M 3-alignment of gold by 0.16-5 MeV proton impact ionization

Abstract

The alignment of the M 3 subshell of gold following proton impact ionization was studied with projectile energies in the range from 160 keV up to 5MeV. The experiments were performed by measuring the poIarization of emitted M X-rays be means of a 5 in. Johansson crystal spectrometer. A good agreement of the experimental data and the results of theoretical SCA calculations was found.

p3/2-alignment following heavy ion impact

“…During the experiments it became evident that the PET crystal was not very resistive against radiation damages mostly by scattered ions. Fortunately, the effects on the X-ray spectra were small and could be corrected for by normalizing the lines of interest to the L~ and M~ lines, resp., which are only weakly polarized (for details see: Bliimke et al [8]). …”

“…42Mo L X-ray spectra and v9Au M X-ray spectra were measured with a second setup, as described by Btiimke etal. [8], using a PET crystal (2d=8.74~), which reflects the lines with largest polarization, i.e. Mo L~ and Au M 3 Nt, at 0 = 44.7 ° and 0 = 45.7 °, respectively.…”

“…As in the case of L3 alignment it was shown that these calculations describe well the M 3 alignment of the concerned elements following proton impact, too (cf. [8,12] . Fig.…”

“…; O-to t is the total ionization cross section of the concerned subshell whereas aio, gives the cross section of the impact ionization. In order to account for the observed multiple ionization, the Coster-Kronig factors f~ as well as the subshell ionization cross section ratios in (8) should be taken from measurements or calculations for multiple vacancy configurations. As far as we know such Coster-Kronig rates are not available for the target atomic numbers used here.…”

“…[1,2,3,4]) but is less investigated for the M3 shell (3p3/2) [5,6,7,8]. The latter were done only after ionization by protons.…”