Production of H− fragments in collisions of OH+ ions with atoms and molecules

Emission of negative charged particles has been studied in collisions of OH+ ions with gas jets of Ar atoms and acetone molecules at keV energies. A relatively strong contribution of negative hydrogen ions was found in both collision systems. According to a kinematic analysis, the observed H− ions were produced in close atom-atom collisions. Non negligible H− production in biological tissues could be relevant in ion therapy.