Observation of H+ desorption stimulated by the impact of metastable helium atoms

H+ desorption induced by the impact of metastable helium atoms (He∗) with a thermal kinetic energy has been observed. The measurements were carried out for an alkali metal (K, Na)-covered Ni(110) surface using a time-of-flight technique and a pulsed-discharge-type He∗ source. It is concluded that the H+ desorption by He∗ is induced by a hole created on the valence levels via the Auger deexcitation of He∗.