X-ray polarimetry with a micropattern TPC
Abstract
The micropattern time projection chamber (TPC) offers a novel method of imaging the tracks of photoelectrons as a means of X-ray polarimetry with the potential to simultaneously achieve large modulation factors and high quantum efficiency. Measurements with a simple prototype micropattern TPC polarimeter, with an 18 mm-atm absorption depth of a mixture of 50% neon and 50% dimethyl ether, result in a modulation factor of 45.0±0.6% with polarized 6.4 keV X-rays. With unpolarized 5.9 keV X-rays, the measured modulation factor is 0.49±0.54%, consistent with zero. The geometry of the TPC polarimeter will enable substantial improvements in quantum efficiency without the loss of modulation.
- Publication:
-
Nuclear Instruments and Methods in Physics Research A
- Pub Date:
- November 2007
- DOI:
- 10.1016/j.nima.2007.08.144
- Bibcode:
- 2007NIMPA.581..755B
- Keywords:
-
- 07.60Fs;
- 07.85.Fv;
- 29.40.Gx;
- 95.55.Ka;
- X- and gamma-ray sources mirrors gratings and detectors;
- Tracking and position-sensitive detectors;
- X- and gamma-ray telescopes and instrumentation