Eur. Phys. J. D (2013) 67: 199
https://doi.org/10.1140/epjd/e2013-40276-1

Colloquium

Modelling low energy electron and positron tracks in biologically relevant media

¹ Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, 28040 Madrid, Spain
² Centro de Investigaciones Energéticas Medioambientales y Tecnológicas, Avenida Complutense 22, 28040 Madrid, Spain
³ Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
⁴ Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain
⁵ Centre for Medical Radiation Physics, University of Wollongong, 2522 NSW, Australia

^a e-mail: g.garcia@iff.csic.es

Received: 30 April 2013
Received in final form: 29 July 2013
Published online: 25 September 2013

Abstract

This colloquium describes an approach to incorporate into radiation damage models the effect of low and intermediate energy (0–100 eV) electrons and positrons, slowing down in biologically relevant materials (water and representative biomolecules). The core of the modelling procedure is a C++ computing programme named “Low Energy Particle Track Simulation (LEPTS)”, which is compatible with available general purpose Monte Carlo packages. Input parameters are carefully selected from theoretical and experimental cross section data and energy loss distribution functions. Data sources used for this purpose are reviewed showing examples of electron and positron cross section and energy loss data for interactions with different media of increasing complexity: atoms, molecules, clusters and condense matter. Finally, we show how such a model can be used to develop an effective dosimetric tool at the molecular level (i.e. nanodosimetry). Recent experimental developments to study the fragmentation induced in biologically material by charge transfer from neutrals and negative ions are also included.