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An electrohydrodynamic (EHD) technique is used to generate ions from liquid metals. Liquid metal is fed to the tip of a capillary needle emitter with a voltage difference applied between the emitter and an extractor electrode to produce an intense electric field at the liquid surface. Electrostatic forces overcome surface tension forces to produce ions by field emission. When using liquid cesium, time-of-flight mass analysis showed the ion current to be primarily Cs+ with a small percentage of Cs2+ and Cs3+. Electron currents of over 1 mA have been produced by operating the emitter at 2 kV negative. Besides cesium, alkali ion beams have been generated using NaK/cesium alloy and sodium. Calculations show that liquid metals of low work functions appear more suitable for production of atomic ions while higher work functions metals may produce multiatomic ions and charged droplets in addition to atomic ions.

Measured Li + + Li total charge-transfer cross sections are reported and compared with the computed results of Peek, Green, Perel, and Michels based on an ab initio twostate calculation. Both experiment and theory show oscillatory structure in the cross sections with very good agreement in cross-section magnitude and oscillatory structure. There exist, however, small but important differences in the oscillation characteristics.

A crossed-beam technique was used to measure total nonresonant charge-transfer cross sections of the following reactions over an energy range from about 0. 5 to 20 keV: Li' +Cs Li+Cs, Li +Rb-Li+Rb, Li'+K Li+K, Hg++Cs Hg+ Cs'. For each reaction, the minimum energy defect occurs for transfer to an excited state. The cross sections show typical nonresonant characteristics with the measured maxima corresponding to these energy defects. The production of photons resulting from deexcitation of the Li (2p) state formed by charge-transfer collisions was also measured over the same energy range for the reactions involving Li. These photon cross sections (with larger experimental uncertainties than the total cross sections) were "normalized" to the total cross section in the near-adiabatic region using semiempirical relationships.Transfer to an excited state is the dominant channel in the 'near-adiabatic region with transfer to the ground state becoming increasingly important with increasing impact velocity. The discussion of the Hg + Cs results includes statistical weight considerations.

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