ArK x-ray production cross sections in collisions with highly ionized Cu at 50?70 MeV

Abstract

The projectile charge state dependence of Ar K x-ray production in collisions with Cu 11 § through Cu22+ions has been investigated at ~1 MeV/amu. A distinct change in the behaviour of the cross section as a function of charge state q was observed for q> 19 where CuL shell vacancies are brought into the collision. The assumption that the vacancy production is predominantly due to 2pa-2pn electron promotion via rotational coupling leads to a consistent description of the data.

Saturation effect in projectile- and target- x-ray production in collisions between 2.5 MeV/u highly charged Cu ions and gaseous targets

“…The target spectra were recorded with and without the target gas in the same geometrical set-up and background was found to be negligible in the region of interest. In the case of Ne-like Cu ions, Schiebel and Doyle [13] observed considerable background counts which were generated due to the metastable ions (3s 2p 5 3 P 2 ) present in the beam originating after poststripper foil. All the present measurements were carried out at several gas pressures between 1.0 T (for Xe) and 3.5 T (for H 2 ) measured at the entrance of the effusive jet.…”

“…This increment in the K XRP cross sections is due to the electron transfer from Ar K-shell to Cu L-shell. Schiebel and Doyle [13] have also observed increment in the Ar K XRP cross sections in collisions with Cu 11+ through Cu 22+ ions at 66 MeV. The measured K XRP cross sections are compared in figure 5 with the calculations of the ECPSSR theory, a perturbed-stationary state approach that accounts for Table 4.…”