THE MPI AIT X-RAY IMAGER (MAXI) - HIGH-SPEED PN CCDS FOR X-RAY-DETECTION

MAXI (MPI/AIT X-ray Imager) is part of a proposal submitted to the European Space Agency (ESA) as focal plane instrumentation of the X-ray Multi Mirror Mission (XMM). Within a collaboration of 13 European institutes we have proposed a fully depleted (sensitive) pn CCD of 280 μm thickness with a homogeneous sensitive area of 36 cm2 and a pixel size of 150×150 μm2 which is well matched with the telescope's angular resolution of 30 arcsec translating to a position resolution of approximately 1 mm in the focal plane. The X-ray sensitivity will be higher than 90% from 250 eV up to 10 keV, the readout time in the full frame mode of the complete focal plane will be 2 ms with a readout noise of better than 5 e- (rms). Prototypes of all individual components of the camera system have been fabricated and tested. The camera concept will be presented. The measured transfer properties of the CCD and the on-chip electronics will be treated. Taking into account the coupling of the on-chip amplifier to the following front-end electronics the expected performance will be derived. © 1990.