X-ray-emission measurements following charge exchange between C${}^{6+}$ and H${}_{2}$

X-ray-emission measurements following charge exchange between C $^{6 +}$ and H $_{2}$

M. Fogle, D. Wulf, K. Morgan, D. McCammon, D. G. Seely, I. N. Draganić, and C. C. Havener

Phys. Rev. A 89, 042705 – Published 28 April 2014

Abstract

Lyman x-ray spectra following charge exchange between C $^{6 +}$ and H $_{2}$ are presented for collision velocities between 400 and 2300 km/s (1–30 keV/amu). Spectra were measured by a microcalorimeter x-ray detector capable of fully resolving the C vi Lyman series emission lines though Lyman- $δ$ . The ratios of the measured emission lines are sensitive to the angular momentum $l$ states populated during charge exchange and are used to gauge the effectiveness of different $l$ -distribution models in predicting Lyman emission due to charge exchange. At low velocities, we observe that both single-electron-capture and double-electron-capture autoionization contribute to Lyman emission and that a statistical $l$ distribution best describes the measured line ratios. At higher velocities single-electron capture dominates with the $l$ distribution peaked at the maximum $l$ .