Investigation of Interactions Between Low Energy Positrons and DNA Using the Monte-Carlo Method

Abstract

Positron Emission Tomography (PET) is the imaging system used to diagnose an illness. Positrons from a radioactive nucleus are injected into the patient. There are few existing papers on the energy loses of positrons especially with low energy in the biological target. So, in this study, the goal was to investigate how low kinetic energy positrons (20eV-10keV) interact with DNA by using the Monte-Carlo simulation. In the simulation, screened Rutherford scattering Formula where Wentzel screening parameter was used for elastic collisions, algorithm proposed for the electron-matter interactions of re-edited version of positron interaction was used for inelastic collisions. Because positron-matter interaction involves randomness, the simulation was done using the Monte Carlo Method. In this simulation the screened Rutherford scattering formula using Wentzel screening parameters for elastic collisions and the electron-matter interaction model suggested by Liljequist for inelastic collisions were rearranged in order to determine positron interaction. The stopping powers of adenine, guanine, thymine, cytosine compounds and DNA were determined and compared with that of other related results. The results were found to be considerably higher than reported in some other papers.