Linear polarization of x-ray photons in HFQ transitions of polarized He-like ions with application to the search for parity nonconservation effects

Abstract

Theoretical concepts in the production and controlling of polarized highly charged ion beams in storage rings are investigated. A scheme for the control of the degree of ion beam polarization, based on the observation of the linear polarization of emitted x-ray photons in hyperfine quenched (HFQ) decay of excited levels of polarized He-like ions, is presented. One of the important motivations for the production of polarized ion beams is the possibility of observing the parity nonconservation (PNC) effects in HFQ transitions in He-like highly charged ions, where these effects can reach an unprecedented high value for atomic physics. The measurement of these effects requires online diagnostics of the degree of ion beam polarization. The possible schemes for such experiments as well as estimates of the magnitude of the observable PNC effects are presented.