The DEPFET pixel BIOSCOPE

The DEPFET pixel Bioscope system based on a DEPFET pixel matrix provides good spatial and energy resolution in real-time digital autoradiography. Due to its very low noise and an optimized entrance window the online detection of tritium without vacuum or cooling is demonstrated for the first time. To achieve this milestone a p-channel junction field effect transistor on a fully depleted high ohmic silicon substrate (DEPFET) is used as unit cell for pixel detectors providing an excellent noise performance of 158 eV FWHM at 6 keV (12 e ENC) at room temperature (300 K). 64×64 DEPFET pixel matrices with square (50 μm×50 μm) or hexagonal (50 μm×42 μm) pixels have been developed and operated successfully. First measurements result in a homogeneous charge collection efficiency on the whole matrix area and a good linearity in the X-ray range from 5 keV to 60 keV. First images taken with the square and the hexagonal pixel matrices using an ⁵⁵ Fe-source as well as a “proof of principle” experiment for online ³H-detection are presented and discussed