Cross section calculations in condensed media: charged particles in liquid water.

Ionisation cross sections for charged particles are deduced within the framework of the relativistic plane wave first Born approximation and the classical electromagnetic theory. The macroscopic dielectric response function is related to the atomic generalised oscillator strength. Interaction cross sections for proton impact on liquid water are presented and discussed. A semi-empirical model for the angular distribution of secondary electrons produced by proton impact on liquid water, which is based on the Bethe approach, is presented.