Microscopic studies of atom–water collisions

The influences of water molecules surrounding biological molecules during irradiation with heavy particles (atoms, ions) are currently a major subject in radiation science on a molecular level. In order to elucidate the underlying complex reaction mechanisms, we have initiated a joint experimental and theoretical investigation with the aim to make direct comparisons between experimental and theoretical results. As a first step, studies of collisions of a water molecule with a neutral projectile (C atom) at high velocities (≥≥0.1 a.u.), and with a charged projectile (proton) at low velocities (≤≤0.1 a.u.) have been studied within the microscopic framework. In particular, time-dependent density functional theory (TDDFT) was applied to the valence electrons and coupled non-adiabatically to molecular dynamics (MD) for ionic cores. Complementary experimental developments have been carried out to study projectile interactions with accelerated (≤≤10 keV) and mass-selected cluster ions. The first size distributions of protonated water cluster ions H+(H2O)n(nn = 2–39) produced using this new apparatus are presented.

The influences of water molecules surrounding biological molecules during irradiation with heavy particles (atoms, ions) are currently a major subject in radiation science on a molecular level. In order to elucidate the underlying complex reaction mechanisms we have initiated a joint experimental and theoretical investigation with the aim to make direct comparisons between experimental and theoretical results.Figure optionsDownload as PowerPoint slide