Fragmentation d'agrégats d'hydrogène Hn+ par collision unique avec un atome d'hélium à 60 keV/uma

Abstract

Fragmentation of mass-selected 60-keV/amu Hn⁺ induced by single collision on helium is observed for n = 9,25 and 31. The absolute cross sections of the charged fragments are measured from mass 3 to n-2. The deduced inclusive mass distributions appear strongly different from those obtained at lower energy where mainly molecular evaporation is involved. An important production of fragments of masses which are intermediate between the masses of the evaporated dimers and the ones of the resulting ionic fragments is observed.