Collisional Quenching of Metastable X-Ray-Emitting States in a Fast Beam of He-like Fluorine

Abstract

High-resolution x-ray spectral measurements are used to determine the relative intensity of He-like fluorine x-ray transitions, $2^{3}P_{1}\ensuremath{\rightarrow}1^{1}S_{0}$ and $2^{1}P_{1}\ensuremath{\rightarrow}1^{1}S_{0}$, produced in 30-MeV ${\mathrm{F}}^{5+}$ collisions with Ne, Ar, and Kr gas targets at various pressures. The relative intensities are observed to be strong functions of both gas pressure and target $Z$. The data permit extraction for the first time of the total quenching cross sections (${\ensuremath{\sigma}}_{Q}$) for fast fluorine ions in the $1s2p^{3}P_{1}$ state. The measured ${\ensuremath{\sigma}}_{Q}$ are found to be approximately geometrical in size.