Characterization of x-ray detectors in the MIT x-ray polarimetry beamline

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 183eV (Boron Kα) to 705eV (Fe Lα) using a laterally graded multilayer coated mirror (LGML) oriented at 45 degrees to the source. The position angle of the polarization can be rotated through a range of roughly 150°. 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° 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.