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N 6+ +H and O 6+ +H charge exchange. Y. Wu, P. C. Stancil University of Georgia H. P. Lieberman, R. J. Buenker Bergische Universitat Wuppertal D. R. Schultz, Y. Hui , C. C. Havener Oak Ridge National Laboratory. ADAS 16 th , Auburn, 06-10-2011. Outline. Background Theoretical Methods
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N6+ +H and O6+ +H charge exchange Y. Wu, P. C. StancilUniversity of GeorgiaH. P. Lieberman, R. J. BuenkerBergische Universitat WuppertalD. R. Schultz, Y. Hui , C. C. HavenerOak Ridge National Laboratory ADAS 16th, Auburn, 06-10-2011
Outline • Background • Theoretical Methods • Results • Summary
Background • Charge exchange: X-rays and/or EUV photons observed in cometary and planetary atmosphere and from the heliosphere; • Oq+, Cq+, Neq+, Mgq+, Siq+, Nq+, Sq+,... • X-ray/EUV: study the solar wind composition and its variation; the interaction of the solar wind with comets and planetary atmosphere; the atmospheres in the Solar System etc. Oq+ + H → O(q-1)+(nl) + H+ O(q-1)+(nl) → O(q-1)+(n’l’) + hν
Theoretical Methods N6+(1s) + H → N5+(1s nl)+ H+ O6+(1s2) + H → O5+(1s2nl) + H+ • MOCC (Molecular orbital close-coupling) • AOCC (Atomic orbital close-coupling) • CTMC (Classical orbital Monte-Carlo)
Molecular orbital close-coupling calculations (MOCC) • Full quantum, molecular orbital close-coupling; • Low energy collision, ≤ a few keV amu-1; • [Aq+ + B] as a quasi-molecule (perturbed stationary-state approximation) ; • The multi-reference single-and double-excitation configuration interaction approach (MRDCI): potentials, radial and rotational couplings.
Results Adiabatic Potential: N6+(1s) + H → N5+(1s nl)+ H+
Results Adiabatic Potential: O6+(1s2) + H → O5+(1s2nl) + H+
Results Basis set optimization highly charged ion: A hybrid basis set: • The standard Dunning neutral atom basis: inner core electrons; • One-electron basis of hydrogen-like orbitals: highly excited electron. The latter basis was optimized to reproduce nearly exactly the hydrogen-like Rydberg ion energies.
Results Asymptotic energy: [NH]6+ singlet states The largest energy difference less than 0.05 eV!!
Results Asymptotic energy: [OH]6+ The largest energy difference is about 0.03 eV!!
Results Total cross section: N6+(1s) + H → N5+(1s nl)+ H+
Results n-resolved cross section : N6+(1s) + H → N5+(1s nl)+ H+ Agree well for the dominant n=4 channels between MOCC, AOCC, CTMC
Results nl-resolved cross section: N6+(1s) + H → N5+(1s nl)+ H+
Results Total cross section: O6+(1s2) + H → O5+(1s2nl) + H+ 1, Good agreement in the a large energy range ; 2,Strong effect of rotational couplings
Results Similar effect found in C4+/H, Al3+/H, Si2+/H, M Gargaudt, et al, JPB Effect s of rotational couplings: (a) Total cross section; (b) State-selective cross section
Results Compared O6+/H with N6+/H 1, Good agreement; 2, Core effect;
Summary • A recommended set of cross sections are deduced based on the MOCC, AOCC, and CTMC and experiment; • Aid in X-ray modeling studies; • Core effect of the highly charged ions; • Strong effects of the rotational couplings: O6++H This work is partially supported by NASA grants NX09AV46G, NNG09WF24I, and NNH07ZDA001N.