Coulomb-deflection effect in inner-shell ionization by heavy charged particles

Abstract

$K$-shell x-ray production cross sections were measured for $_{28}\mathrm{Ni}(K)$ in collision with $_{1}^{1}\mathrm{H}$ ions of kinetic energies 55 to 300 keV, $_{1}^{2}\mathrm{H}$ ions of 100 to 300 keV, and $_{2}^{4}\mathrm{He}$ ions of 200 to 300 keV; for $_{46}\mathrm{Pd}(K)$ with $_{1}^{1}\mathrm{H}$ ions of 215 to 300 keV, and for $_{47}\mathrm{Ag}(K)$ with $_{1}^{1}\mathrm{H}$ ions of 200 to 300 keV. $L$-shell x-ray cross sections were measured for $_{47}\mathrm{Ag}(L)$ in collision with $_{1}^{1}\mathrm{H}$ ions of kinetic energies 35 to 300 keV, with $_{1}^{2}\mathrm{H}$ ions of 60 to 300 keV, with $_{2}^{4}\mathrm{He}$ ions of 110 to 300 keV, and for $_{79}\mathrm{Au}(L)$ with $_{1}^{1}\mathrm{H}$ ions of 140 to 300 keV. The collisions conditions were such that the effect of the projectile energy loss during the ionizing collision became significant for the $K$-shell ionizations, but remained unimportant for the $L$-shell ionizations. The measurements extend the experimental range of the Coulomb-deflection variable $d{q}_{0S}$ over previous measurements for the shells $S=K$ by a factor \ensuremath{\sim} 1.2, and for $S=L$ by a factor \ensuremath{\sim} 2. This permits a decisive test of current theories for the effect of the deflection of the projectile in the Coulomb field of the target nucleus on inner-shell ionization cross sections.