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Abstract
Photon polarization analysis and coincidence techniques have been used to determine the relative importance of rotational and radial coupling for charge transfer in proton-helium collisions. Polarization analysis of the L(,(alpha)) photon from the 2p-1s transition of the excited hydrogen atom, formed by charge transfer, indicates the relative importance of the two coupling mechanisms is the same order of magnitude.
Coincidence measurements of the polarization pattern are made for a variety of scattering angles at proton energies of 4 keV, 5 keV and 8 keV. The scattering angle is then related to an impact parameter.
The experimental results presented here suggest the primary mechanism for charge transfer to H(2p) is through an intermediate state by coupling at a diabatic molecular potential curve crossing. Calculations of the amplitudes associated with this coupling are made by application of the Landau-Zener model with allowance for rotational coupling. The calculated values agree with the experimental magnitudes of the relative magnetic substate cross sections, but do not agree with the measured relative phase for the amplitudes. A model for the origin of the observed phase is presented.
