Many-electron-multicenter CTMC study of charge exchange collisions of solar wind ions with CO

CARIATORE, N. D.; OTRANTO, S.

San Carlos de Bariloche

Conferencia; 17th International Conference on the Physics of Highly Charged Ions; 2014

Charge exchange processes between charged ions and atomic or  molecular neutrals are particularly relevant in the astrophysical environment. These processes take place whenever solar wind ions impact over cometary comas or planetary atmospheres [1]. Since many of these ions are highly charged, capture takes place to excited states and the subsequent electronic rearrangement leads to EUV or X-ray emission. Since 1996, when the first X-ray emission from a comet was recorded by ROSAT, systematic explorations of the line emission cross sections associated to these collision systems have been pursued at JPL, KVI, LLNL-EBIT, NIST-EBIT, the University of Reno, and Berlin-EBIT.In this work, we concentrate on CO, an important cometary neutral which is also present in the atmospheres of Venus and Mars. A many-electron-multicenter classical-trajectory Monte Carlo (mmCTMC) model is developed and tested in charge-exchange studies involving projectiles with charges from +3 to +10 in the fast solar wind regime (~3.0 keV/amu). To estimate the direct contribution of the multiple capture mechanism, we used a the Auger decay model formerly developed by Ali et al. [2]. The present model is contrasted against simpler single-center (SC) and independent-atom (IA) approaches. Total and state-selective charge-exchange cross sections are presented and are compared to recent data from the Jet Propulsion Laboratory where available.