Author :
Kishimoto, Y. ; Gunji, S. ; Ishigaki, Y. ; Kanno, M. ; Murayama, H. ; Ito, C. ; Tokanai, F. ; Suzuki, K. ; Sakurai, H. ; Mihara, T. ; Kohama, M. ; Suzuki, M. ; Hayato, A. ; Hayashida, K. ; Anabuki, N. ; Morimoto, M. ; Tsunemi, H. ; Saito, Y. ; Yamagami, T
Abstract :
We have been developing an instrument termed "PHENEX(Polarimetry for High ENErgy X rays)" to measure polarization in the hard X-ray region. The PHENEX polarimeter consists of detector modules called "unit counters". We have investigated the performance of the unit counter, using a highly polarized beam in KEK-PF BL14A. From these measurements, we obtained a detection efficiency of 20% and a modulation factor (analyzing power for polarization) of 53% for 80 keV X rays. Assembling four unit counters, a balloon-flight version was constructed and carried out a preliminary observation of the Crab Nebula in Jun. 13th, 2006. During this flight, the PHENEX polarimeter observed the Crab for about one hour and detected its hard X rays with a significance of 16 sigma. From this result, we project that a PHENEX polarimeter with nine "unit counters" would detect the hard-X-ray polarization of the Crab Nebula with the significance of 3 sigma in a 3-hour observation.
Keywords :
X-ray astronomy; X-ray detection; X-ray sources (astronomical); astronomical instruments; astronomical polarimetry; nebulae; polarimeters; 3 hour; 80 keV; AD 2006 06 13; Crab Nebula; KEK-PF BL14A; PHENEX; Polarimeter for High ENErgy X rays; Electromagnetic scattering; Extraterrestrial measurements; Particle scattering; Photomultipliers; Plastics; Polarimetry; Polarization; Radiation detectors; Synchrotron radiation; X-ray scattering; Crab Nebula; astrophysics; hard x ray; polarimeter;
