Charge exchange cross sections in slow collisions of Si$^{3+}$ with Hydrogen atom

In recent years both the experimental and theoretical studies of electron transfer in ion-atom collisions have progressed considerably. Accurate determination of the cross sections and an understanding of the dynamics of the electron-capture process by multiply charged ions from atomic hydrogen over a wide range of projectile velocities are important in various field ranging from fusion plasma to astrophysics. The soft X-ray emission from comets has been explained by charge transfer of solar wind ions, among them S$^{\mbox{i3}}$+, with neutrals in the cometary gas vapor. The cross sections are evaluated using the (a) full quantum [1] and (b) semi-classical molecular orbital close coupling (MOCC) [2] methods. Adiabatic potentials and wave functions for relavent singlet and triplet states are generated using the MRDCI [3] structure codes. Details will be presented at the conference. \\[4pt] [1] L. B. Zhao, D. C. Joseph, B. C. Saha, H. P. Liebermann, P. Funke and R.J. Buenker, Phys. Rev A, 79, 034701 (1009). [2] M. Kimura and N.F. Lane, At. Mol. Opt. Phys 26, 79 (1990). [3] R. J. Buenker,``Current Aspects of Quantum Chemistry 1981, Vol 21, edited by R. Carbo (Elsevier, Amsterdam) p 17.