The contribution of ultra-low energy secondary electrons to nanoscopic radial dose profiles in condensed phase LIF facing the challenge

Electrons of ultra-low energy in the range from 10 eV to keV play an important, but yet little understood, role in the fields of radiation protection, dosimetry and most crucially in nanodosimetry. Electrons also play a role in cancer proton therapy, where cascades of secondary electrons are produced in the proton slowing-down-process. Electrons of very low energy can initiate toxic processes in human body cells, by induced damage to bio-molecules via ionizations/excitations and the resulting destruction of chemical bonds. Even sub-ionization secondary electrons in the energy range 1-10 eV, for a long time thought to be relatively harmless, can promote damage to biomolecules due to ''dissociative electron attachment''. Clearly, it is important to minimize the effects of irradiation in oncological and other clinical procedures on the healthy tissues in proximity to the diseased cells. The investigation of these important issues via theoretical modeling/simulations of the interaction of electrons with the matter are usually carried out by Monte Carlo techniques and are considered a crucial step towards a robust theoretical interpretation and understanding of the experimental observations. Information about radiation induced effects by heavy charged particles (HCPs) in the condensed phase is expected to yield insight into these processes in biological tissue. An example of calculated secondary electrons spectra from 6MeV protons in water