Large-Area Balloon-Borne Polarized Gamma Ray Observer (PoGO)
2005 (English)In: Proceedings of the 22nd Texas Symposium on Relativistic Astrophysics at Stanford, 2005, 736-743 p.Conference paper (Refereed)
We are developing a new balloon-borne instrument (PoGO), to measure polarization of soft gamma rays (30-200 keV) using asymmetry in azimuth angle distribution of Compton scattering. PoGO is designed to detect 10 % polarization in 100mCrab sources in a 6-8 hour observation and bring a new dimension to studies on gamma ray emission/transportation mechanism in pulsars, AGNs, black hole binaries, and neutron star surface. The concept is an adaptation to polarization measurements of well-type phoswich counter consisting of a fast plastic scintillator (the detection part), a slow plastic scintillator (the active collimator) and a BGO scintillator (the bottom anti-counter). PoGO consists of close-packed array of 217 hexagonal well-type phoswich counters and has a narrow field-of-view (~ 5 deg2) to reduce possible source confusion. A prototype instrument has been tested in the polarized soft gamma-ray beams at Advanced Photon Source (ANL) and at Photon Factory (KEK). On the results, the polarization dependence of EGS4 has been validated and that of Geant4 has been corrected.
Place, publisher, year, edition, pages
2005. 736-743 p.
Computer simulation, Electromagnetic wave polarization, Imaging techniques, Monte Carlo methods, Optimization, Orbits, Photons, Radiation detectors, Solar system, Synchrotron radiation
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:kth:diva-81265OAI: oai:DiVA.org:kth-81265DiVA: diva2:500860
22nd Texas Symposium on Relativistic Astrophysics, Stanford California, December 13-17, 2004
QC 201203282012-02-132012-02-102012-03-28Bibliographically approved