title: Fragmentation of water by heavy ions.
abstract: Absolute cross sections for fragmentation of water molecules by C3+ and O5+ ions over an energy region where the Bragg peak maximizes were measured for ionization, electron capture, and electron loss channels. A collision regime where sigmaSigmaOq+> or =sigmaH2O+ was reached for the first time, producing large abundances of H+ and O+ fragments in comparison to proton impact. Our findings have straightforward implications in the subsequent fast chemistry at the ionization site and on the O production in the first stages of water radiolysis. An unexpected channel-independent relationship between the cross sections for the fragmentation products, which is also approximately independent of the particle type, energy, and charge state, is found. A model is presented to explain such behavior allowing the cross sections of all fragmentation products to be obtained from single and double electron removal cross sections.
authors.affiliation: Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, Caixa Postal 38071, Rio de Janeiro 22452-970, Brazil.
authors.forename: H
authors.initials: H
authors.lastname: Luna
authors.forename: E C
authors.initials: EC
authors.lastname: Montenegro