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Title: Beam Test of a Prototype Phoswich Detector Assembly forthe PoGOLite Astronomical Soft Gamma-ray Polarimeter

Abstract

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.

Authors:
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Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
897727
Report Number(s):
SLAC-PUB-12299
TRN: US0701502
DOE Contract Number:
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nuclear Instrumentation and Methods (NIM) A
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; COMPTON EFFECT; DESIGN; ELECTRONS; KEK PHOTON FACTORY; PHOTONS; POLARIMETERS; POLARIZATION; SYNCHROTRON RADIATION; SYNCHROTRONS; Astrophysics,ASTRO, INST, SYNCHRAD

Citation Formats

Kanai, Y., Ueno, M., Kataoka, J., Arimoto, M., Kawai, N., /Tokyo Inst. Tech., Yamamoto, K., Mizuno, T., Fukazawa, Y., /Hiroshima U., Kiss, M., Ylinen, T., Bettolo, C.Marini, Carlson, P., /Royal Inst. Tech., Stockholm, P.Chen d, B.Craig d, T.Kamae d, G.Madejski d, J.S.T.Ng, Rogers, R., Tajima, H., Thurston, T.S., /SLAC, Saito, Y., Takahashi, T. /JAXA, Sagamihara, Gunji, S., /Yamagata U., Bjornsson, C-I., Larsson, S., and /Stockholm U. /Ecole Polytechnique /KEK, Tsukuba. Beam Test of a Prototype Phoswich Detector Assembly forthe PoGOLite Astronomical Soft Gamma-ray Polarimeter. United States: N. p., 2007. Web. doi:10.1016/j.nima.2006.09.109.
Kanai, Y., Ueno, M., Kataoka, J., Arimoto, M., Kawai, N., /Tokyo Inst. Tech., Yamamoto, K., Mizuno, T., Fukazawa, Y., /Hiroshima U., Kiss, M., Ylinen, T., Bettolo, C.Marini, Carlson, P., /Royal Inst. Tech., Stockholm, P.Chen d, B.Craig d, T.Kamae d, G.Madejski d, J.S.T.Ng, Rogers, R., Tajima, H., Thurston, T.S., /SLAC, Saito, Y., Takahashi, T. /JAXA, Sagamihara, Gunji, S., /Yamagata U., Bjornsson, C-I., Larsson, S., & /Stockholm U. /Ecole Polytechnique /KEK, Tsukuba. Beam Test of a Prototype Phoswich Detector Assembly forthe PoGOLite Astronomical Soft Gamma-ray Polarimeter. United States. doi:10.1016/j.nima.2006.09.109.
Kanai, Y., Ueno, M., Kataoka, J., Arimoto, M., Kawai, N., /Tokyo Inst. Tech., Yamamoto, K., Mizuno, T., Fukazawa, Y., /Hiroshima U., Kiss, M., Ylinen, T., Bettolo, C.Marini, Carlson, P., /Royal Inst. Tech., Stockholm, P.Chen d, B.Craig d, T.Kamae d, G.Madejski d, J.S.T.Ng, Rogers, R., Tajima, H., Thurston, T.S., /SLAC, Saito, Y., Takahashi, T. /JAXA, Sagamihara, Gunji, S., /Yamagata U., Bjornsson, C-I., Larsson, S., and /Stockholm U. /Ecole Polytechnique /KEK, Tsukuba. Wed . "Beam Test of a Prototype Phoswich Detector Assembly forthe PoGOLite Astronomical Soft Gamma-ray Polarimeter". United States. doi:10.1016/j.nima.2006.09.109. https://www.osti.gov/servlets/purl/897727.
@article{osti_897727,
title = {Beam Test of a Prototype Phoswich Detector Assembly forthe PoGOLite Astronomical Soft Gamma-ray Polarimeter},
author = {Kanai, Y. and Ueno, M. and Kataoka, J. and Arimoto, M. and Kawai, N. and /Tokyo Inst. Tech. and Yamamoto, K. and Mizuno, T. and Fukazawa, Y. and /Hiroshima U. and Kiss, M. and Ylinen, T. and Bettolo, C.Marini and Carlson, P. and /Royal Inst. Tech., Stockholm and P.Chen d, B.Craig d, T.Kamae d, G.Madejski d, J.S.T.Ng and Rogers, R. and Tajima, H. and Thurston, T.S. and /SLAC and Saito, Y. and Takahashi, T. /JAXA, Sagamihara and Gunji, S. and /Yamagata U. and Bjornsson, C-I. and Larsson, S. and /Stockholm U. /Ecole Polytechnique /KEK, Tsukuba},
abstractNote = {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.},
doi = {10.1016/j.nima.2006.09.109},
journal = {Nuclear Instrumentation and Methods (NIM) A},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 17 00:00:00 EST 2007},
month = {Wed Jan 17 00:00:00 EST 2007}
}
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  • A combined {gamma}-ray probe/{beta}{sup {+-}} imaging detector was created by modification of a beta imaging intra-operative probe. This phoswich detector consists of a thin CaF{sub 2}(Eu) {beta}{sup {+-}} imaging disk, coupled through a light diffuse to 7 or 19 parallelepiped high-Z scintillation crystals arranged hexagonally in columns. These elements are either 2 x 2 x 10 mm{sup 3} or 4 x 4 x 10 mm{sup 3} LSO, GSO or BGO crystals, and act as both light guides for the imaging light and as intrinsic {gamma} detectors. The coincidence between the CaF{sub 2} (Eu) and phoswich scintillators identifies {beta}{sup +} ormore » true {beta}{sup {minus}} events and suppresses accompanying annihilation or background {gamma} events. The phoswich crystals are in turn coupled through optical fibers to a multi-channel PMT with positioning and discrimination electronics. Various characteristics of this novel imaging phoswich detector are investigated and presented for each of the phoswich combinations including: detector anisotropy, effects of time blocking and energy windows on phoswich imaging, intrinsic singles and phoswich spectral and spatial resolution characteristics, and phoswich imaging ability within {gamma} background environments. The performance characteristics of the assembled prototype devices demonstrate that in surgery, this device can be used three ways: (1) rapid localization of {gamma} emitting radionuclides with the modestly directional, self-collimated phoswich crystals; (2) high resolution {beta}{sup {minus}} imaging or coarse (annihilation background corrupted) {beta}{sup +} imaging in singles mode; or (3) {beta}{sup +} imaging in coincidence mode with reduced {gamma} background contamination.« less
  • A new apparatus for polarimetric and ellipsometric measurements based on the rotating-analyzer method in the soft x-ray region has been designed, constructed, and installed in the soft x-ray beamline (BL-11) at the SR Center of Ritsumeikan University, Shiga, Japan. It can realize the optical configurations for the complete polarization analysis by using six independently movable drive shafts. A demonstration of the capabilities of the apparatus has been performed using Mo/Si multilayer polarizers deposited by an ion beam sputtering method. It is for the first time shown that the degree of linear polarization of monochromatized light from the BL-11 is approximatelymore » 87% at 92 eV since the beamline has been constructed.« less
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