Abstract
Measurements are reported of mutual neutralisation of Li+ and H- ions for interaction energies between 33.3 and 2400 eV. When the results are compared with similar measurements for H+/H-, He+/H- and H+2/H- they provide further evidence that cross sections for neutralisation of singly charged positive ions by H-, when plotted against relative speed, fall close to a common curve for speeds greater than 3*105 m s-1. Neutralisation of Na+ by O- has been measured between 27 and 2470 eV and the results compared with earlier measurements taken at lower energies by Moseley et al. (1975) and Weiner et al (1971).