Performance of the PRAXyS X-ray polarimeter

Abstract

The performance of the Time Projection Chamber (TPC) polarimeter for the Polarimeter for Relativistic Astrophysical X-ray Sources (PRAXyS) Small Explorer was evaluated using polarized and unpolarized X-ray sources. The PRAXyS mission will enable exploration of the universe through X-ray polarimetry in the 2-10 keV energy band. We carried out performance tests of the polarimeter at the Brookhaven National Laboratory, National Synchrotron Light Source (BNL-NSLS) and at NASA's Goddard Space Flight Center. The polarimeter was tested with linearly polarized, monochromatic X-rays at 11 different energies between 2.5 and 8.0 keV. At maximum sensitivity, the measured modulation factors at 2.7, 4.5 and 8.0 keV are 27%, 43% and 59%, respectively and the measured angle of polarization is consistent with the expected value at all energies. Measurements with a broadband, unpolarized X-ray source placed a limit of less than 1% on false polarization in the PRAXyS polarimeter.

Gaseous and dual-phase time projection chambers for imaging rare processes

“…Other TPCs that emphasize image reconstruction, in astronomy and applied science, involve x-ray polarimetry through the accurate reconstruction of the photoelectron (e.g. [413][414][415][416]), γ-ray polarimetry through pair production [77], Compton Cameras [417] and thermal neutron detectors [418]. They are particularly synergetic with many TPCs described in this review.…”

A convolutional neural network approach for reconstructing polarization information of photoelectric X-ray polarimeters

“…Refs. 3,14,23,24). However, it is complicated to optimize a cut region in the two (or more) parameter plane (or space).…”

Instrumentation and Future Missions in the Upcoming Era of X-ray Polarimetry

“…The TPC design was proposed on board GEMS [68][69][70][71][72] and PRAXyS [73][74][75][76] mission proposals. The GPD design was proposed in the past in many mission proposals (the most relevant are: IXO [77], NHXM [78], POLARIX [79], ESA Medium class mission XIPE [80]) and currently in the IXPE mission [81,82] approved by NASA and eXTP mission [83] selected as background mission 1 by the Chinese Academy of Sciences.…”