  A Compton camera is the most promising approach for gamma-ray detection in
the energy region from several hundred keV to MeV, especially for application
in high energy astrophysics. In order to obtain good angular resolution,
semiconductor detectors such as silicon, germanium and cadmium telluride(CdTe)
have several advantages over scintillation detectors, which have been used so
far. Based on the recent advances of high resolution CdTe and silicon imaging
detectors, we are working on a Si/CdTe Compton camera. We have developed
64-pixel CdTe detectors with a pixel size of 2mmx2mm and double-sided Si strip
detectors(DSSDs) with a position resolution of 800 micron. As a prototype
Si/CdTe Compton camera, we use a DSSD as a scatterer and two CdTe pixel
detectors as an absorber. In order to verify its performance, we irradiate the
camera with 100% linearly polarised 170keV gamma-rays and demonstrate the
system works properly as a Compton camera. The resolution of the reconstructed
scattering angle is 22 degrees(FWHM). Measurement of polarization is also
reported. The polarimetric modulation factor is obtained to be 43%, which is
consistent with the prediction of Monte Carlo simulations.
