Laboratory Measurement of 50-300eV X rays from Collisions of S, Ne ions with molecules of Cometary Interest.

Approximately 90 percent of the observed cometary x rays have energies in the 50 -- 300 eV range. It is assumed these x rays may be the result of electron capture to excited states, similar to the explanation of the 250 -- 700 eV cometary x-ray lines being due to the transfer of electrons from cometary gases (CO, H$_{2}$O, etc.). The present data are consistent with this interpretation. We present here spectra obtained, using solar wind-type ions such as Ne$^{7+}$, Ne$^{8+}$, S$^{9+}$, and O$^{6+}$ from the JPL ECR ion source. Our spectra suggest that charge transfer to these highly-charged solar wind species contributes significantly to cometary x-ray spectra in the 50-300eV energy range.