First experimental results of a new gamma-ray detector based on a Silicon Drift Chamber coupled to a Scintillator

A γ-ray detector consisting in a CsI(Tl) scintillator coupled to a Silicon Drift Chamber (SDC), has been realized and tested. Experimental results, obtained with a prototype based on a scintillator of 3 mm diameter and 5mm thickness and on a SDC of the same diameter with on-chip electronics, are reported here. The peculiar noise characteristics of the SDC allow this γ-ray detector to operate on a wide energy range with high resolution. An energy threshold of about 10 keV at room temperature and of few keV at 0°C has been measured. At 662 keV the detector shows an energy resolution of 4.34% FWHM at room temperature, to our knowledge the best result ever obtained with a scintillator.