Light collection of POLAR detector

TL;DR

This paper presents simulations and optimizations of light collection in the POLAR detector's plastic bars, achieving high uniformity for polarization measurements of gamma-ray bursts.

Contribution

It introduces a detailed simulation study optimizing surface polishing and covering to improve light collection uniformity in the POLAR detector.

Findings

Achieved 89% amplitude uniformity with prototype

Surface polishing significantly affects light uniformity

Simulation results guide detector design improvements

Abstract

POLAR is a compact polarimeter dedicated to measure the polarization of GRBs between 50-300 keV. The light collection of 200*6*6mm3 plastic bars has been simulated and optimized in order to get uniform response to x-rays at different points of one single bar. According to the Monte Carlo results, the amplitude uniformity strongly depends on the polishing level of scintillator surface and the covering. A uniformity of 89% is achieved with a prototype constructed by a non position-sensitive PMT and an array of 4X4 bars.