The DEPFET pixel BIOSCOPE

Abstract

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 a thin 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/spl times/64 DEPFET pixel matrices with square (50 /spl mu/m/spl times/50 /spl mu/m) or hexagonal (50 /spl mu/m/spl times/42 /spl mu/m) 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 /sup 55/Fe-source as well as a 'proof of principle' experiment for online /sup 3/H-detection are presented and discussed.