The TRISTAN 166-pixel detector: Preliminary results with a planar setup

We present the first experimental results achieved with a monolithic array of 166 Silicon Drift Detectors (SDD). This detector was developed for the TRISTAN experiment, targeting the search for a sterile neutrino in the keV mass range by means of accurate Beta spectroscopy of the Tritium decay. We briefly report on the design and characterization with X-rays of the full signal chain: from the SDD array, operated in a planar configuration with all the components of the final system, to the acquisition platform simultaneously acquiring all 166 channels. The average energy resolution is better than 250 eV FWHM at 5.9 keV at a temperature of 0 degrees C, a 6 mu s shaping time, and an average count rate of 1 kcps per channel, 100 times smaller than the final experiment one.