Design of the AGIPD sensor for the European XFEL

Abstract

For experiments at the European X-ray Free-Electron Laser (XFEL) the Adaptive Gain Integrating Pixel Detector (AGIPD) is under development. The particular requirements for the detector are a high dynamic range of 0, 1 to more than 104 12.4keV photons per pixel for an XFEL pulse duration of <100fs, and a radiation tolerance of 1GGy. The nominal operating voltage is 500V, however for special applications an operation close to 1000V should be possible. Experimental data on the dose dependence of the oxide-charge density at the Si–SiO2 interface and the surface-current density have been used in TCAD simulations and the layout of the pixels and guard-rings optimized. Finally the expected performance, in particular breakdown voltage, dark current and inter-pixel capacitance as function of X-ray dose are given.