title: Electron recombination in ionized liquid argon: a computational approach based on realistic models of electron transport and reactions.
abstract: In this work, we propose a new theoretical approach to modeling the electron-ion recombination processes in ionization tracks in liquid argon at 87 K. We developed a computer simulation method using realistic models of charge transport and electron-ion reactions. By introducing the concept of one-dimensional periodicity in the track, we are able to model very large cylindrical structures of charged particles. We apply our simulation method to calculate the electron escape probability as a function of the initial ionization density in the track. The results are in quantitative agreement with experiment for radiation tracks of relatively high ionization density. At low ionization densities, the simulation results slightly overestimate the experimental data. We discuss possible reasons for this disagreement and conclude that it can be explained by the role of δ tracks (short tracks of secondary electrons) in electron-ion recombination processes. We introduce an approximate model that takes into account the presence of δ tracks and allows the experimental data obtained from a liquid-argon ionization detector to be reproduced over a wide range of ionization density.
authors.affiliation: Institute of Applied Radiation Chemistry, Technical University of Lodz, Lodz, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Jaskolski
authors.forename: Mariusz
authors.initials: M
authors.lastname: Wojcik
mesh_terms: D001128:Argon / Q000737:chemistry*; D003198:Computer Simulation; D004579:Electron Transport; D004583:Electrons; D007477:Ions / Q000737:chemistry; D008956:Models, Chemical
chemical_list: D007477:Ions; D001128:Argon