LABORATORY MEASUREMENT OF CHARGE TRANSFER CROSS-SECTIONS FOR PROTON + HYDROGEN AND PROTON + DEUTERON COLLISIONS AT LOW RELATIVE VELOCITIES
COGAN, JOHN DENNIS
Doctor of Philosophy
Total charge transfer cross sections for the reaction H('+)+H(ls) (--->) H(ls) + H('+) and the isotopic reaction H('+)+D (ls) (--->) H (ls) + D('+) are presented for collisions at center of mass energies ranging from 0.05 eV to 150 eV. These data were experimentally determined by the technique of merged beams. This reaction is the most fundamental charge transfer reaction and is also one of the primary processes resulting in loss of hydrogen from the upper atmosphere. The apparatus is described and a number of experimental difficulties associated with laboratory study of the reaction are discussed. A summary of theoretical treatments is also presented. The results include the first cross sections measured at collision energies below 1 eV. Agreement with theory at energies above 10 eV is excellent. The results below 5 eV agree with the best quantum mechanical calculations only to within about 30%. Possible causes of the disagreement are discussed.