Energy Deposition Models at the Molecular Level in Biological Systems

Abstract

Abstract In this study we have developed a model to describe the electron interaction of intermediate and high energy electrons (10–10000 eV) with some molecules of biological interest. Differential and integral electron scattering cross sections have been calculated with an optical potential method following an independent atom representation. Important improvement related to relativistic corrections, many-body effects, local velocity considerations and a screening correction procedure which take into account the overlapping of the constituent atoms in the molecule have been introduced to improve the accuracy and applicability of the method for a high variety of molecular targets. The accuracy of these calculations has been checked by comparison with total electron scattering cross section data we have measured in a transmission beam experiment with experimental errors within 5%. Finally, we have developed a Monte Carlo simulation program, based on the general tools of GEANT4, which uses as input parameters our calculated cross sectional data and the energy loss distribution functions based on the experimental energy loss spectra. This simulation procedure allows energy deposition models at the molecular level that could be very useful in biological and medical applications when microscopic energy deposition patterns are required.