Eur. Phys. J. D (2013) 67: 123
https://doi.org/10.1140/epjd/e2013-20508-2

Regular Article

A random walk approach to the diffusion of positrons in gaseous media

¹ Departamento de Física, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, Santa Catarina, Brasil
² Departamento de Física, Universidade Federal da Fronteira Sul, 85770-000 Realeza, Paraná, Brasil
³ Departamento de Física, Universidade do Estado de Santa Catarina, 89223-100 Joinville, Santa Catarina, Brasil

^a e-mail: wtenfen@gmail.com

Received: 1 September 2011
Received in final form: 14 March 2013
Published online: 27 June 2013

Abstract

In this work, we present a random walk model to study the positron diffusion in gaseous media. The positron-atom interaction is described through positron-target cross sections. The main idea is to obtain how much energy a positron transfer to the environment atoms, through ionizations and electronic excitations until its annihilation, taking the ratio between each energetically available collision channel to the total one as the probability for each process to occur. As a first application, we studied how the positron diffuse in gases of helium, neon, argon and their mixtures. To characterize the positron dynamics in each system, we calculated the radiation profile generated from the annihilation, their diffusion profiles and the most probable distances for excitation and ionization.