Computation of Nearly Exact 3D Electrostatic Field in Gas Ionization Detectors

Abstract

The three-dimensional electrostatic field configuration in gas ionization detectors has been simulated using an efficient and precise nearly exact boundary element method (NEBEM) solver set up to solve an integral equation of the first kind. This recently proposed formulation of BEM and the resulting solver use exact analytic integral of Green function to compute the electrostatic potential for charge distribution on flat surfaces satisfying Poisson's equation. As a result, extremely precise results have been obtained despite the use of relatively coarse discretization leading to successful validation against analytical results available for two-dimensional MWPCs. Significant three dimensional effects have been observed in the electrostatic field configuration and also on the force experienced by the anode wires of MWPCs. In order to illustrate the applicability of the NEBEM solver for detector geometries having multiple dielectrics and degenerate surfaces, it has been validated against available FEM and BEM numerical solutions for similar geometries.