Beam test of a prototype phoswich detector assembly for the PoGOLite astronomical soft gamma-ray polarimeter

Y. Kanai*, M. Ueno, J. Kataoka, M. Arimoto, N. Kawai, K. Yamamoto, T. Mizuno, Y. Fukazawa, M. Kiss, T. Ylinen, C. Marini Bettolo, P. Carlson, W. Klamra, M. Pearce, P. Chen, B. Craig, T. Kamae, G. Madejski, J. S.T. Ng, R. RogersH. Tajima, T. S. Thurston, Y. Saito, T. Takahashi, S. Gunji, C. I. Bjornsson, S. Larsson, F. Ryde, G. Bogaert, S. Kishimoto

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


We report about the beam test on a prototype of the balloon-based astronomical soft gamma-ray polarimeter, PoGOLite (Polarized Gamma-ray Observer - Light Version) conducted at KEK Photon Factory, a synchrotron radiation facility in Japan. The synchrotron beam was set at 30, 50, and 70 keV and its polarization was monitored by a calibrated polarimeter. The goal of the experiment was to validate the flight design of the polarimeter. PoGOLite is designed to measure polarization by detecting a Compton scattering and the subsequent photo-absorption in an array of 217 well-type phoswich detector cells (PDCs). The test setup included a first flight model PDC and a front-end electronics to select and reconstruct valid Compton scattering events. The experiment has verified that the flight PDC can detect recoil electrons and select valid Compton scattering events down to 30 keV from background. The measure azimuthal modulations (34.4%, 35.8% and 37.2% at 30, 50, and 70 keV, respectively) agreed within 10% (relative) with the predictions by Geant4 implemented with dependence on the initial and final photon polarizations.

Original languageEnglish
Pages (from-to)61-71
Number of pages11
JournalNuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Issue number1
Publication statusPublished - 2007 Jan 1
Externally publishedYes


  • Balloon experiment
  • Hard X-ray
  • Polarization
  • Soft gamma-ray

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Instrumentation


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