Line ratios for soft-x-ray emission following charge exchange between O8+ and Kr

Lyman spectra and line ratios are reported for soft-x-ray emissions following the charge exchange process in 293, 414, 586, and 1256 km/s O8+ and Kr collisions. Lyman series from Ly-alpha to Ly-epsilon were resolved for the O7+ ion using a high-resolution x-ray quantum microcalorimeter detector. It is found that the observed line ratios are dependent on the nl distribution of the captured electron, and the Ly-alpha and Ly-beta x-ray emissions are enhanced. Moreover, by comparing the measured line ratios to the constructed theoretical single charge exchange line ratios for O8+ + H, it is suggested that autoionizing double capture plays a significant role in the enhancement of Ly-alpha and Ly-beta emissions for the present system.