CROSS SECTIONS FOR ELECTRON CAPTURE INTO EXCITED LEVEL N=6 OF HYDROGEN BY 5-KEV TO 70-KEV PROTONS IN MG VAPOR AND IN NEON

An optical technique has been used to investigate electron capture into the excited level n=6 of hydrogen by 5- to 70-keV protons passing through magnesium vapor or neon. Photons from the Balmer Hδ transition which are emitted downstream of the target were analyzed with a grating spectrometer and counted. From these the population of the level n=6 and the cross section for electron capture into n=6 have been obtained. Cross-section estimates for ionization of the level n=6 collisions with Mg atoms are also presented. The electron-capture cross sections are consistent with n-3 extrapolations of electric-gap measurements for capture into higher quantum levels (n9to15) reported by Il'in and co-workers, Futch and Moses, and Riviere. The results are compared with those of various theoretical models. © 1969 The American Physical Society.