Charged particle interactions in water: cross-sections and simulation

Detailed knowledge of the microscopic distribution of interactions and especially of the energy deposited in irradiated matter is of prime interest in gaining an understanding of radiation action. Monte Carlo event-by-event simulations are particularly suitable for such studies. The development of such codes necessitates accurate interaction cross-sections for all the important collision processes, most notably for inelastic collisions that result in energy transfer. A semi-theoretical formalism for constructing the relevant cross-sections for the water medium is presented.