Interpretation of Experimental Differential Elastic Scattering Cross Section forH++ Ne

Abstract

95'7electron's energy are not accounted for in the model. These would be expected to be larger for the smaller nuclei. A more detailed examination of the formulation is required to see if one can retain the basic simplicity of the impulse model and obtain corrections for these effects. publication with the understanding that no limitation shall exist on the reproduction and distribution of its published or unpublished form in whole or in part for any purpose of the U. S. Government.The result of a differential scattering experiment of H by Ne at 5. 71-eV collision energy is compared to the differential cross section predicted by (a) a JWKB partial-wave calculation based on a potential model, (b) a similar calculation based on the ab initio Peyerimhoff calculated intermolecular potential for the NeH' system, and (c) a new and more efficient calculational scheme developed by Remler involving Regge poles. The agreement of the Peyerimhoff prediction, (b), with the experimental data is very good. Differences between the Peyerimhoff potential and the final values of the parameters retrieved from the iterative calculation in (a), as well as implicit ambiguities of (a) in reproducing the features of a low-resolution experiment, are discussed in terms of semiclassical theory and the Remler-Regge method.

On Regge trajectories for ion-atom and atom-atom potentials

“…The derivation of equation (1) starts by differentiating equation (4) for A = A n with respect to E [2, p: 104]. If the result of this operation is multiplied by ~b and subtracted from the original equation multiplied by de~dE, it is found that r d~b dr…”

“…Applications have been made to : ion-atom collisions and the inversion of elastic scattering data [3][4][5][6][7][8][9]21], electron-atom collisions [8,9], quasi-stationary states [7][8][9][10][11][12], and elastic scattering in the presence of chemical reaction [13,19,20]. Semiclassical, variational and direct numerical integration methods have also been developed for calculating the positions of Regge Poles and their residues [7][8][9][10][11][12].…”

“…Regge Pole and complex angular momentum techniques [1,2] have recently been applied to several elastic scattering problems in atomic and molecular physics [3][4][5][6][7][8][9][10][11][12][13][14][19][20][21]. Applications have been made to : ion-atom collisions and the inversion of elastic scattering data [3][4][5][6][7][8][9]21], electron-atom collisions [8,9], quasi-stationary states [7][8][9][10][11][12], and elastic scattering in the presence of chemical reaction [13,19,20].…”

The practical inversion problem in molecular beam scattering

“…As we get closer to 8,, branch points 3 and 4 come too close together to allow evaluation of Equation (4) by stationary phase. Since, as Ford and Wheeler show [9], beyond 8, this rainbow contribution to oSc (8) decays exponentially, then eventually this problem dies out. Thus, beyond a certain point the rainbow region has ceased to be important and only branches 1 and 2 contribute.…”

“…The second region is around the rainbow region defined by Equation (8). As we get closer to 8,, branch points 3 and 4 come too close together to allow evaluation of Equation (4) by stationary phase.…”