Monte Carlo calculations of low energy positrons in silicon

The penetration of charged particles through matter is determined by the outcomes of countless Coulomb collisions with atoms and atomic electrons. It is a useful schematization to classify these collisions as soft and hard. Soft collisions, with impact parameters large compared to atomic dimensions are extremely numerous, and give rise to small energy losses and deflections. Hard collisions, with small impact parameters are much less frequent and result in large energy losses and deflections. Both types of collisions make essential contributions to the transport process [4]. The dynamics of each individual collision should be known accurately for a reliable Monte Carlo simulation of such events. The atomic collisions of charged particles, as many body problems [13] are very difficult to solve exactly, therefore several approximations, which are valid in various incoming particle energy regions, are made to find solutions. A low-energy positron beam may be thought as the antimatter complement to the electron beams found in many diagnostic probes and other useful devices. The exciting field of low-energy positron research has been revolutionized by the introduction of slow-positron beams. Once positron is injected into the material, it suffers elastic and inelastic scattering events. Because both scattering processes are important in determining, for example, particle ranges and backscattering probabilities, it is difficult experimentally to study any particular process in isolation. The Monte Carlo simulation technique, in which the particle trajectories are Monte Carlo calculations of low energy positrons in silicon Asuman Aydin