Polarimetry in astronomy for the hard X- and soft /spl gamma/-ray energy range has not been developed much to date. Indeed no dedicated polarimeters have ever been launched either in space or as a balloon-borne experiment. We propose a polarimetry project for hard X-ray and soft gamma-ray astrophysics known as the Coded Imager and Polarimeter for High Energy Radiation (CIPHER) telescope. The novel design of this telescope, using a matrix of thick CdTe microspectrometers as the detection plane, will allow this type of measurement to be performed for the first time by a dedicated instrument. In order to compare the results already obtained from simulations with experiment, we have constructed a prototype detector of 4/spl times/4 pixels, to study the response of this concept of polarimeter to linearly polarized radiation in the 100 keV to 1 MeV energy range. The use of a beamline at the European Synchrotron Radiation Facility (ERSF) allowed us to study double event efficiency and distribution, for beams of nearly 100% linearly polarized radiation in the energy range from 100 keV to 1 MeV. Polarimetric Q factors higher than 0.4 for relative efficiencies higher than 20% were observed. The photon beam energy and detector thickness dependencies will be discussed, comparing these experimental results with those calculated by Monte Carlo simulations.
[1]
M. McConnell,et al.
Instrument description and performance of the Imaging Gamma-Ray Telescope COMPTEL aboard the Compton Gamma-Ray Observatory
,
1993
.
[2]
Ezio Caroli,et al.
Hard x-ray polarimetry with a thick CdTe position sensitive spectrometer
,
2000,
SPIE Optics + Photonics.
[3]
F. Lei,et al.
Compton Polarimetry in Gamma-Ray Astronomy
,
1997
.
[5]
Ezio Caroli,et al.
Monte Carlo simulations of the design of a hard x-ray telescope optimized for polarimetry
,
2003,
SPIE Astronomical Telescopes + Instrumentation.
[6]
Monte Carlo polarimetric simulations of a hard x-ray energy telescope
,
2002,
SPIE Optics + Photonics.
[7]
E. Caroli,et al.
Monte Carlo Polarimetric Efficiency Simulations for a Single Monolithic CdTe Thick Matrix
,
2001
.