Characterization of X-ray Detectors in the MIT X-ray Polarimetry Beamline

TL;DR

This paper details the development and characterization of X-ray detectors tested in the MIT X-ray Polarimetry Beamline, including their efficiency and imaging capabilities for polarized X-ray applications.

Contribution

It introduces a comprehensive setup for testing various X-ray detectors in polarized X-ray beams and compares their performance in the soft X-ray band.

Findings

Demonstrated nearly 100% polarized X-ray generation at multiple energies.

Compared quantum efficiencies of different CCD and sCMOS detectors.

Provided detailed imaging results for various detectors in soft X-ray band.

Abstract

The MIT X-ray Polarimetry Beamline is a facility that we developed for testing components for possible use in X-ray polarimetry. Over the past few years, we have demonstrated that the X-ray source can generate nearly 100% polarized X-rays at various energies from 183 eV (Boron K$\alpha$) to 705 eV (Fe L$\alpha$) using a laterally graded multilayer coated mirror (LGML) oriented at 45\deg\ to the source. The position angle of the polarization can be rotated through a range of roughly 150\deg. In a downstream chamber, we can orient a Princeton Instruments MTE1300B CCD camera to observe the polarized light either directly or after reflection at 45\deg\ by a second LGML. In support of the REDSoX Polarimeter project, we have tested four other detectors by directly comparing them to the PI camera. Two were CCD cameras: a Raptor Eagle XV and a CCID94 produced by MIT Lincoln Laboratories, and two had sCMOS sensors: the Sydor Wraith with a GSENSE 400BSI sensor and a custom Sony IMX290 sensor. We will show results comparing quantum efficiencies and event images in the soft X-ray band.