Gamma-Ray Instrument for Polarimetry, Spectroscopy
نویسندگان
چکیده
We present an instrument concept called GIPSI that uses germanium strip detectors in an imaging system to provide narrow line sensitivity < 8:0 10 6 cm 2 s 1 at 100 keV in a 2 week exposure (3 ), and which has a point spread function (spatial resolution) of approximately 20 arc minutes rms. The germanium strip detectors also make an excellent polarimeter by capitalizing on the angular dependence of the Compton scattering cross section. Gamma-ray polarimetry in the energy band around 60{300 keV is an interesting area of high energy astrophysics where observations have not been possible with the technologies employed in current and past space missions. We have tested a prototype detector with polarized beams and have measured a modulation factor of approximately 0.8 at 100 keV. A sensitive instrument can be realized on a modest space mission or a long duration balloon ight. Linear polarization can be detected in sources such as the Crab Pulsar, Cen A, Cyg X{1, and solar ares down to less than 5% of the source ux. The proposed instrument would have a collecting area of 400 cm.
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