| Автор | H R J Walters |
| Дата выпуска | 1980-12-28 |
| dc.description | An exact calculation of the (plane-wave) second Born exchange amplitude for elastic electron-hydrogen scattering at 30 eV is reported. It is shown that exchange coupling to excited states is as important as exchange with the 1s state (at 30 eV) and that in the forward angular region it acts in the opposite direction to 1s exchange (at least in perturbation theory). A closure approximation to the second-order exchange amplitude is compared with the exact numbers. Poor agreement is obtained but it is not clear whether this results from a bad choice of average energy epsilon or is an intrinsic failing of the closure method. If the closure approximation can be made to work then a value of epsilon greater than -<sup>1</sup>/<sub>18</sub> au would seem to be indicated. The Glauber approximation to the exchange amplitude is criticised on the basis that it involves using a closure approximation with epsilon = epsilon <sub>1s</sub>=-<sup>1</sup>/<sub>2</sub> au. An exploratory calculation shows that second-order exchange does exert a pronounced effect on the differential cross section. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Exact second Born exchange amplitude for elastic electron-hydrogen scattering |
| Тип | lett |
| DOI | 10.1088/0022-3700/13/24/004 |
| Print ISSN | 0022-3700 |
| Журнал | Journal of Physics B: Atomic and Molecular Physics |
| Том | 13 |
| Первая страница | L749 |
| Последняя страница | L755 |
| Аффилиация | H R J Walters; Dept. of Appl. Math. & Theoretical Phys., Queen's Univ. of Belfast, Belfast, UK |
| Выпуск | 24 |
