Application of double-sided silicon strip detectors to Compton cameras

We have developed a Compton camera with a double-sided silicon strip detector (DSSD) for hard X-ray andgamma-ray observation. Using a DSSD as a scatter detector of the Compton camera, we achieved high angularresolution of 3.4 at 511 keV. Through the imaging of various samples such as two-dimentional array sources anda diuse source, the wide “eld-of-view ( 100 ) and the high spatial resolution (at least 20 mm at a distance of60 mm from the DSSD) of the camera were con“rmed. Furthermore, using the List-Mode Maximum-LikelihoodExpectation-Maximization method, the camera can resolve an interval of 3 mm at a distance of 30 mm from theDSSD.Keywords: Compton Camera, Double-sided Sillicon Strip Detector, CdTe Pixel Detector, Gamma-ray Astron-omy1. INTRODUCTIONA Compton camera is a promising approach for high-sensitivity observation of the hard X-ray and gamma-ray bands. 1 9 The observation in these energies could provide unique information on the universe, such asnucleosynthesis and particle acceleration. Furthermore, high-sensitivity imaging spectroscopy in the energyrange is also attractive in the ground-based “elds, such as medical, biological and industrial. The detectionmethod of Compton cameras, tracking Compton scattering process of photons with position and energy sensitivedetectors, is dicult and complex, but, has a great potential for bringing a breakthrough in the energy bands.For the high sensitivity observation, we have developed the double-sided silicon strip detector (DSSD) asa scatter detector of the Compton camera. In order to improve an angular resolution of a Compton Camerato attain higher sensitivity than the previous Compton Cameras based on scintillator