K-shell vacancies at swift sulphur ions in Gd host

Abstract

Single and double K-vacancy fractions at sulphur ions inside Gd are measured for ion velocities between 7v0 and 14v0 (v0=c/137) using the probe layer technique. These measurements, in combination with the available transient field (TF) precession data at 8v0, yield the degree of polarizationp1s=0.15(3) for such ions in polarized Gd host. This value is considerably smaller than the generally accepted value of 0.24 for light ions. The present results when considered along with the recently reported small values ofp1s for32S and40Ar ions at a velocity ofZv0 in Gd suggestvelocity independence andZ dependence in the polarization transfer mechanism for TF.