Large-Area Balloon-Borne Polarized Gamma Ray Observer (PoGO)

Conference · Thu Jun 30 00:00:00 EDT 2005

OSTI ID:881248

Andersson, V; Chen, P; Kamae, T; Madejski, G; Mizuno, T; Ng, J; Tajima, H; Thurston, T; Bogaert, G; Fukazawa, Y; Saito, Y; Takahashi, T; Barbier, L; Bloser, P; Harding, A; Hunter, S; Krizmanic, J; Mitchell, J; Streitmatter, R; Fernholz, R ; Groth, E

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 ({approx} 5 deg{sup 2}) 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.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 881248
• Report Number(s): SLAC-PUB-11094
• Conference Information: Prepared for 22nd Texas Symposium on Relativistic Astrophysics at Stanford University, Stanford, California, 13-17 Dec 2004
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ADVANCED PHOTON SOURCE
ANL
ASTROPHYSICS
Astrophysics
ASTRO
ASYMMETRY
BLACK HOLES
COMPTON EFFECT
DETECTION
DIMENSIONS
DISTRIBUTION
NEUTRON STARS
PHOSPHORS
PHOTONS
PLASTIC SCINTILLATORS
POLARIZATION
PULSARS