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,

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;  O q+, C q+, Ne q+, Mg q+, Si q+, N q+, S q+,...  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. O q+ + H → O (q-1)+ (nl) + H + O (q-1)+ (nl) → O (q-1)+ (n’l’) + hν

Theoretical Methods N 6+ (1s) + H → N 5+ (1s nl)+ H + O 6+ (1s 2 ) + H → O 5+ (1s 2 nl) + 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 ;  [A q+ + 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.

Adiabatic Potential: N 6+ (1s) + H → N 5+ (1s nl)+ H + Results

Radial coupling matrix elements: [NH] 6+

Rotational coupling matrix elements : [NH] 6+

Adiabatic Potential: O 6+ (1s 2 ) + H → O 5+ (1s 2 nl) + H + Results

Radial coupling matrix elements : [OH] 6+

Rotational coupling matrix elements : [OH] 6+

Basis set optimization highly charged ion: A hybrid basis set: i) The standard Dunning neutral atom basis: inner core electrons; ii) 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

Results Asymptotic energy: [OH] 6+

Results Total cross section: N 6+ (1s) + H → N 5+ (1s nl)+ H +

n-resolved cross section : N 6+ (1s) + H → N 5+ (1s nl)+ H + Results Agree well for the dominant n=4 channels between MOCC, AOCC, CTMC

nl-resolved cross section: N 6+ (1s) + H → N 5+ (1s nl)+ H + Results

1, Good agreement in the a large energy range ; 2,Strong effect of rotational couplings Total cross section: O 6+ (1s 2 ) + H → O 5+ (1s 2 nl) + H +

Effect s of rotational couplings: (a) Total cross section; (b) State-selective cross section Results Similar effect found in C 4+ /H, Al 3+ /H, Si 2+ /H, M Gargaudt, et al, JPB

Compared O 6+ /H with N 6+ /H Results 1, Good agreement; 2, Core effect;

 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: O 6+ +H This work is partially supported by NASA grants NX09AV46G, NNG09WF24I, and NNH07ZDA001N. Summary

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