Negative ion source

The negative ion source application in production of energetic neutral atom beams is avantageous; these neutral atom beams are used, for instance, as an efficient mean of heating at thermonuclear temperatures plasmas producted in magnetic confinement fusion devices. The good neutralization rate (>60%) of H- and D- ions at these high energies make them more interesting than positive ions for production of atom beams having an energy in excess of 80 keV/nucleon. The recent discovery of a strong production of H- and D- negative ions by dissociative attachment to H2 and D2 molecules having a strong vibrational excitation and the observation of strong negative ion densities in hydrogen and deuterium plasmas have suggested the H- and D- negative ion extraction from multicusp type plasma generators