Development of a Thomson X-ray Polarimeter

TL;DR

This paper reports on the design, development, and preliminary testing of a Thomson X-ray polarimeter for small satellite missions, including detector configurations, collimator design, and calibration tools.

Contribution

It introduces two detector geometries for the polarimeter and presents initial test results and calibration methods for the instrument.

Findings

Rectangular detectors have been fabricated and tested.

A collimator with flat topped response was developed for pointing offset compensation.

Preliminary test results demonstrate the feasibility of the design.

Abstract

We describe the current status of the design and development of a Thomson X-ray polarimeter suitable for a small satellite mission. Currently we are considering two detector geometries, one using rectangular detectors placed on four sides of a scattering element and the other using a single cylindrical detector with the scattering element at the center. The rectangular detector configuration has been fabricated and tested. The cylindrical detector is currently under fabrication. In order to compensate any pointing offset of the satellite, a collimator with a flat topped response has been developed that provides a constant effective area over an angular range. We have also developed a double crystal monochromator/polariser for the purpose of test and calibration of the polarimeter. Preliminary test results from the developmental activities are presented here.