Silicon Sensors realized by KETEK in Co-operation with FZD

In 2004 Ketek has established a long term co-operation with the Reasearch Centre Dresden (FZD) and the Universität der Bundeswehr München (UBW) targeted on the development of new silicon radiation detectors as well as on their commerz-ialization.
Silicon Drift Detectors (SDDs) are widely used in XRF, TXRF, electron micro-probe analysis systems and synchrotron applications. The big benefit of SDDs compared to other x-ray de-tectors as Si(Li)s or pin-diodes is the spectroscopic performance principally being independent of the sen-sitive area. KETEK offers silicon drift detectors with sizes varying from 10 to 100 mm² whereby the large area devices become more and more attractive for most of the applications. Energy resolution below 130 eV for the Manganese Ka line and peak to background values of more than 10.000 can be achieved for devices with active areas of 100 mm² when cooled down to -60°C. This temperature can be already realized by a Peltier element integrated into the detector module, since the thermal budget of this evacuated device is well optimized. Count rate dependency of the energy resolution and the peak position is negligible up to count rates of 100.000 counts per second.
Silicon Photomultiplier (SiPMs) are single photon sensitive devices built from an avalanche photodiode (APD) array on common Si substrate, whereby the APDs are operated in Geiger modus (above break down voltage). All applications for this sensor are connected with fast low level light sensing like e.g. the indirect gamma radiation detection by a scintillator. The first SiPM prototypes which have been realized by Ketek in co-operation with FZD show promising val-ues for photon detection efficiency, dark rate and opti-cal cross talk. Now this detector shall be further opti-mized for PET application.