SPECTROSCOPY IN THE GRAZING-INCIDENCE SPECTRAL REGION

Résumé
Dans la région spectrale 'grazing incidence', la lumière provenant de la zone de la collision a été focalisée sur la fente d'un spectromètre McPherson Modèle 247 par un miroir ellipsoïdal. Une résolution spatiale d'environ 100 µm a été obtenue. Le spectromètre est contrôlé entièrement par un calculateur qui enregistre les spectres. Des exemples sur les collisions ion-gaz et ion-feuille sont donnés.

Abstract
Mirror focussing of the light emitted in the grazing-incidence spectral region during ion-atom collisions has proven to be an improvement compared with earlier measurements, where the collision region was placed as close as possible to the entrance slit of the spectrometer. The present contribution describes the use of a McPherson Model-247 grazing-incidence spectrometer for the study of ion-atom collisions at the 600-keV heavy-ion accelerator at Aarhus University. An ellipsoidal, gold-coated mirror projects the light from the collision zone onto the spectrometer entrance slit, enabling a spatial resolution of ~ 100 µm in the light source. A simple collision chamber for ion-gas collisions is described. The operation of the spectrometer is steered by a computer ; hence data can be accumulated in both scanning directions. The principle of this automatic recording system, which is especially suited for the study of faint light sources, is discussed. Examples of ion-gas and beam-foil excitations will be shown, and general problems of spectroscopy in this spectral region will be discussed.