Electron beam probe for charge neutralization studies of heavy ion beams Rev.Total charge transfer cross sections for neutralization of He+ ion beams have been measured for 1.0--3.0 keY ions. Time-of-flight methods have been used to identify the forward scattered Heo products from He+ interactions with Ar, H 2 , N 2 , °2, NO, CO, CO 2 , CH., C 2 H. and C 2 H 6 targets. Both elastic and inelastic processes were included in the measurement of fast Heo products. Total charge transfer cross sections are typically 5-15 ;"2 for most of the target gases with the exception of H2 where cross sections are smaller. In the few cases where overlap exists, cross sections measured in the present investigation are in general agreement with previous measurements that have used apparatus designed to collect slow product ions with high efficiency.

The collisional dissociation of 75to 700-keV H2' and H3' by impact on taxgets of He is studied. The formation of excited hydrogen is detected by quantitative measurement of collisionally induced Balmer-& emission; the contributions from 3s, 3p, and 3d levels are separated by a method that utilizes the different lifetime of the excited states. Cross sections are almost the same for each of the 3s, 3P, and 3d states; they vary slowly with projectile energy.

An experimental investigation has been made of the formation of excited hydrogen atoms by charge-transfer neutralization of H+ and collisional dissociation of H, + and Ha'.

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Experimental measurements have been made of the cross sections for dissociation of fast (100–700 keV) H2+ and H3+ ions to give fast H atoms in the 3s excited state; targets for this work were O2, CO, CO2, CH4, C2H6, and C3H8. The technique involved quantitative measurement of Balmer-alpha radiation emitted from fast moving fragments of the dissociated projectile. Contributions to the Balmer-alpha emission from the 3p and 3d levels were eliminated by a method that utilizes the different lifetimes of the 3s, 3p, and 3d states. It is observed that cross sections for H(3s) formation by dissociation on the hydrocarbons all exhibit essentially the same variation with impact energy and increase in magnitude with the complexity of the target; similar behavior is exhibited by the O2, CO, and CO2 group of targets. Comparison of the various cross sections suggests that one cannot assign an effective cross-section value to the constituent atoms of the target molecule.