Development of Double-Sided CdTe Strip Detectors for γ-Ray Imaging and Spectroscopy

By reading out both anode and cathode strips, double-sided CdTe strip detectors can achieve a large area and a high position resolution with few readout channels, which makes them very attractive for X-ray and γ-ray imaging and spectroscopy. We have developed double-sided CdTe strip detectors, 1.28 ×1.28 cm2 in size and 0.5 and 2.0 mm in thickness. Both electrodes are divided into 32 orthogonal strips with a pitch of 400 µm. For a detector of 0.5 mm thickness, the energy resolution was measured to be 1.5 keV (FWHM) at 60 keV. For the 2.0-mm-thick detector, an energy resolution of 8.0 keV (FWHM) at 662 keV was obtained using only the anode signal. By combining both the anode and cathode signals, we successfully improved the spectral performance and measured an energy resolution of 5.9 keV (FWHM) at 662 keV.

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