K-shell ionization cross sections in nearly symmetric collisions by S and Cl impact

Abstract

K-shell ionization cross sections in collisions of S and C1 ions with target atoms with atomic number Z2 = 11-22 have been measured in the energy range from 3.9 to 48 MeV. The data are interpreted in terms of the statistical model of electron diffusion to the continuum. The distribution of K-vacancies between the projectile and the target atoms are discussed in the framework of the vacancy sharing process.

Dependence of theK ? h /K ??-branching ratio on projectile velocity and nuclear charge

“…Because a 1 is a very smooth function of target nuclear charge [11], also the a2/cr 1 ratio should not vary more than 10 ~ by changing the nuclear charge by two units, keeping the projectile velocity constant. Such a smooth dependence has also been found by Woods et al [2] [8J it has been found, that the 2s-shell in 32MeV S on Ar is highly ionized) the theoretical values are to be multiplied by about a factor two.…”

“…In the nearly symmetrical collision systems investigated here the K-vacancies are predominantly produced in the 2p0.-orbital [11]. It can therefore be assumed, that also the double-K-vacancy states are first produced in the 2p o-orbital and are then shared between heavy and light collision partner E8] and the cross section for K~-emission (aK~=) is determined by the product:…”

Molecular-orbital X-rays and their anisotropies in heavy-ion collisions in solids and gases

“…We did not measure absolute MO x-ray cross sections with our apparatus, but only the ratio of the MO x-ray cross section to the projectile+target K x-ray cross section. We measured absolute characteristic K x-ray cross sections in the solid targets by normalization to Rutherford scattering, and took the gas-target cross section from Schuch et al [20]. For comparison with the cross sections of Schmidt-B6cking et al…”