Numerical Simulation of Positron Diffusion in the Heavy Noble Gases Ar, Kr and Xe

Abstract

Numerical simulation has been carried out of positron annihilation and diffusion under the influence of an external temperature and electric field in heavy noble gases. The electric field was varied over the range 0-200 V cm - 1 amagat - 1 (1 amagat ... 2.687 xl 019 atoms cm - 3), whereas the temperature was varied from 300 to 3000 K. It is observed that the decay constant ZeIT increases with increasing atomic mass of the interacting gases He, Ne, Ar, Kr and Xe, while the diffusion coefficient decreases except in the case of neon.