Polarization spectroscopy of excited states produced by double electron capture in the collisions of O6+ ions with neutral gases

We have measured the degree of polarization of the emission line correspond ing to the 1s(2)2s6h - 1s(2)2s7i transition of O4+ ions produced by the dou ble electron transfer in the collisions of O6+ ions with He, Ne, Ar, Kr, Xe , H-2, N-2 and O-2. For all targets, the polarization degrees for this line have positive values in the collision energy range of 60-120 keV. This res ult indicates that the excited states produced in the double electron captu re reactions are strongly aligned to the M-L = 0 magnetic substate as in th e case of most single electron capture process. However, the values for He and H-2, both of which are two electron system, are slightly larger than th ose for others which have more electrons. It is possible that a certain mul tiple electron process has an influence on the alignment of this excited st ate.