Polarization and pressure dependence of 2p-1s transitions in He-like and Li-like neon recoil ions.

Abstract

The pressure dependences of 2p-1s transitions in He-like and Li-like neon recoil ions produced in collisions with 1.4-MeV/amu Ar ions were studied for the purpose of assessing effects of polarization and nonstatistical population mechanisms on the relative intensities of prompt and metastable lines. A Johansson-type curved-crystal spectrometer was employed as an x-ray polarimeter by taking spectra with the plane of the focal circle oriented both parallel and perpendicular to the Ar-ion beam. The data indicate that the He-like $^{1}\mathrm{P}$ and $^{3}\mathrm{P}$ lines are only slightly polarized and that the intensity ratio I${(\mathrm{}}^{1}$P)/I${(\mathrm{}}^{3}$P) is not a linear function of pressure. Both of these results appear to be a direct consequence of serious contamination of the spectral region of interest by unresolved spectator-electron transitions.