Very Large Area Silicon Drift Detector Spectroscopic Performances

The most recent spectroscopic results obtained from the large area silicon drift detector (SDD) realized in the frame of the internal tracking system of the LHC-ALICE experiment will be presented. The SDD detector is the result of a very detailed and progressive optimization devoted to obtain stability, simple use and high production yield. Featuring a thickness of 300 mum and a total sensitive area of about 53cm², it is read out by two arrays of 256 anodes. Implanted high voltage dividers and drift speed calibration injectors allow a very reliable on line control of the performances. As a tracking device this detector can localize with a precision better than 30 mum in the two coordinates the impact point of minimum ionizing particles, in a high multiplicity environment, without ambiguities. This same detector has been provided with low noise readout electronics and its spectroscopic characteristics have been studied. We present the experimental results on the spectroscopic characteristics of this SDD detector for low energy X-rays.