  The European X-ray Free Electron Laser (XFEL), currently being constructed in
Hamburg and planning to be operational in 2017 for users, will deliver 27,000
fully coherent, high brilliance X-ray pulses per second with duration less than
100 fs. The unique features of the X-ray beam pose major challenges for
detectors used at the European XFEL for imaging experiments, in particular a
radiation tolerance of silicon sensors for doses up to 1 GGy for 3 years of
operation at an operating voltage above 500 V. One of the detectors under
development at the European XFEL is the Adaptive Gain Integrating Pixel
Detector (AGIPD), which is a hybrid detector system with ASICs bump-bonded to
p+n silicon pixel sensors. We have designed the silicon sensors for the AGIPD,
which have been fabricated by SINTEF and delivered in the beginning of February
of 2013. To demonstrate the performance of the AGIPD sensor with regard to
radiation hardness, mini-sensors with the same pixel and guard-ring designs as
the AGIPD together with test structures have been irradiated at the beamline
P11 of PETRA III with 8 keV and 12 keV monoenergetic X-rays to dose values up
to 10 MGy. The radiation hardness of the AGIPD sensor has been proven and all
electrical properties are within specification before and after irradiation. In
addition, the oxide-charge density and surface-current density from test
structures have been characterized as function of the X-ray dose and compared
to previous measurements for test structures produced by four vendors.
