Technique for producing negative ions

The paper describes a method for obtaining negative ions from a gas-discharge source when a substance with a low ionization potential - cesium, for example - is added to the principal working substance in the discharge chamber so as to increase its efficiency. When cesium vapour is added to a hydrogen discharge with a transverse magnetic field, the maximum current of negative hydrogen ions increases by several times, the voltage drop across the discharge decreases, and ignition is facilitated. In pulse operation (pulse length 10-3sec) it is possible to obtain a beam of negative hydrogen ions with a current of 20 mA with an output slit 0.05 x 10mm from a plasma source with a discharge chamber with plasmotron geometry when cesium vapour is added