Challenges in Monte Carlo track structure modelling.

Purpose: Although great progress has been made, numerous challenges remain in the development of Monte Carlo (MC) charged-particle track structure simulation models. Such models have evolved from the simple gas phase target models to those using condensed phase interaction data coupled with complex targets representing cellular and molecular constituents of mammalian tissue. A wide choice of MC models is now available ranging from those based on the physics of continuous slowing down, to simulations following each interaction on an event-by-event basis.

Electron Emission from Foils and Biological Materials after Proton Impact.

Electron emission spectra from thin metal foils with thin layers of water frozen on them (amorphous solid water) after fast proton impact have been measured and have been simulated in liquid water using the event-by-event track structure code PARTRAC. The electron transport model of PARTRAC has been extended to simulate electron transport down to 1 eV by including low-energy phonon, vibrational and electronic excitations as measured by Michaud et al. (Radiat.

Modeling energy deposition in trabecular spongiosa using the Monte Carlo code PENELOPE.

The inhomogeneity of the target tissue can play an important role in assessing the radiation dose to critical biological targets. This is particularly relevant for calculations of energy deposition by ionizing radiation within regions of radiosensitive trabecular spongiosa. The main focus of this project is the creation of simple quadric-based geometric models of trabecular spongiosa designed specifically for implementation into the general-purpose Monte Carlo radiation transport code PENELOPE.