Depolarization effects during charge exchange of a polarized tandem beam

Determination of electron-loss cross sections for negative hydrogen ions in gases using polarized projectiles

“…The first considerations of beam-depolarization effects during charge exchange in gases have been made by Haeberli et al [-3] and Clausnitzer et al [4]. They found a depolarization of approximately 0.5 within statistical errors leading to the conclusion that the electron stripping of negative hydrogen is strongly predominated by the two-step process.…”

“…For increasing target thicknesses the two-step process H--~ H~ + plays a more important role. In the neutral hydrogen atom the proton spin interacts with the spin of the electron leading to four different substates I1) to [4). They are usually described with uncoupled base states…”

“…the polarization of these states does not change. However, the other two substates 12) and [4) change in such a way that after half of a Larmor period both electron and proton spin have reversed their direction. Under the assumption that all neutral states are populated at the same time the beam polarization oscillates with a time dependence according to…”