Negative-hydrogen-ion production from a nanoporous 12CaO ∙ 7Al 2 O 3 electride surface

Abstract : A high production rate of negative hydrogen ion was observed from a nanoporous C12A7 electride surface immersed in hydrogen/deuterium low-pressure plasmas. The target was biased at 10-170 V negatively and the target surface was bombarded by H3 + ions from the plasma. The production rate was 1-2 orders higher than a clean molybdenum surface. The measured H-energy spectrum indicates that the major production mechanism is desorption by sputtering. This material has potential to be used as production surface of cesium-free negative ion sources for accelerators, heating beams in nuclear fusion, and surface modification for industrial applications.