Instrument Performance and Simulation Verification of the POLAR Detector

TL;DR

This paper details the performance verification and simulation of the POLAR detector, a satellite instrument designed to measure gamma-ray burst polarization, including beam tests, simulation tools, and comparison of results.

Contribution

It introduces a comprehensive verification process combining beam tests and Monte Carlo simulations for the POLAR detector's polarization measurements.

Findings

Good agreement between measured and simulated performance

Validated the instrument's response to polarization

Identified systematic effects due to non-uniformity

Abstract

POLAR is a new satellite-born detector aiming to measure the polarization of an unprecedented number of Gamma-Ray Bursts in the 50-500 keV energy range. The instrument, launched on-board the Tiangong-2 Chinese Space lab on the 15th of September 2016, is designed to measure the polarization of the hard X-ray flux by measuring the distribution of the azimuthal scattering angles of the incoming photons. A detailed understanding of the polarimeter and specifically of the systematic effects induced by the instrument's non-uniformity are required for this purpose. In order to study the instrument's response to polarization, POLAR underwent a beam test at the European Synchrotron Radiation Facility in France. In this paper both the beam test and the instrument performance will be described. This is followed by an overview of the Monte Carlo simulation tools developed for the instrument. Finally a comparison of the measured and simulated instrument performance will be provided and the instrument response to polarization will be presented.