Caliste HD: A new fine pitch Cd(Zn)Te imaging spectrometer from 2 keV up to 1 MeV

Caliste HD is the last member of the Caliste family of Cd(Zn)Te micro-cameras for space applications. This hybrid component is made of the assembly of one 16 × 16 pixel Cd(Zn)Te detector and eight analog front-end ASIC named IDeF-X HD equipped with 32 spectroscopic channels. The pixels are 625 µm pitch and are surrounded by a 20 µm wide guard ring. The new generation of ASIC has the advantage of having a power consumption 4 times lower as the previous version (0.2 W for the full device) and offers the possibility to extend the dynamic range from 250 keV to 1 MeV. The technology is fully compliant with operation in space (tolerant to radiation, thermal and mechanical constraints). This paper presents the preliminary spectroscopic results obtained with the samples produced so far. At −16°C the sum spectrum built with all single events of the 1 mm-thick Al Schottky detector show an energy resolution of 0.82 keV FWHM at 14 keV and 0.92 keV FWHM at 60 keV. A good uniformity in gain and in noise is measured over the 256 pixels; the low level-threshold is lower than 2 keV for all pixels.