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 corresponding to the 1s22s6h - 1s22s7i transition of O4+ ions produced by the double electron transfer in the collisions of O6+ ions with He, Ne, Ar, Kr, Xe, H2, N2 and O2. For all targets, the polarization degrees for this line have positive values in the collision energy range of 60-120 keV. This result indicates that the excited states produced in the double electron capture reactions are strongly aligned to the ML = 0 magnetic substate as in the case of most single electron capture process. However, the values for He and H2, both of which are two electron system, are slightly larger than those for others which have more electrons. It is possible that a certain multiple electron process has an influence on the alignment of this excited state.