First results with the pn-CCD detector system for the XMM satellite mission

The pn-CCD is a novel CCD type which is developed for fast X-ray imaging and spectroscopy for the X-ray Multi Mirror (XMM) satellite mission. Each 200 × 64 pixel large pn-CCD unit with a sensitive area of 3 × 1 cm2 is a fully depleted detector. Full depletion allows for high photon detection efficiency (> 90% in the energy range of 500 eV-10 keV), for a small input capacitance necessary for low noise signal measurements and for backward illumination. For good time resolution and low noise performance each of the 64 CCD channels is terminated with an integrated input-JFET for signal amplification. With the use of the CMOS Amplifier and Multiplexing Chip (CAMEX64B) it is possible to read out the 64 CCD channels in parallel before they are multiplexed and sent to an ADC. For the first time the system of a 64 channel pn-CCD together with CAMEX64B readout, ADC conversion and data acquisition and storage has been brought into operation. First images of an 55Fe X-ray source are presented and discussed.