Quote
J. Becker et al., “AGIPD—The Adaptive Gain Integrating Pixel Detector for the European XFEL: Development and Status,” in 2011 IEEE Nuclear Science Symposium Conference Record, Piscataway, NJ: IEEE, 2011, pp. 1950–1954. doi: 10.1109/nssmic.2011.6154392
Content
<p>The European XFEL [1] will provide fully coherent, 100 fs X-ray pulses, with up to 10¹² photons at 12 keV. The high intensity per pulse will allow the recording of diffraction patterns of single particles or small crystals in a single shot. Consequently, 2D detectors must handle a wide dynamic range: detection ranging from a single photon to >10⁴ photons per pixel in the same image. An additional challenge is the European XFEL machine itself: an electron bunch train with a 10 Hz repetition rate, consisting of up to 2,700 bunches spaced 220 ns apart. Recorded images must be stored within the pixel during the electron bunch trains and read out in between. To meet these requirements, the European XFEL has launched three detector development projects. The AGIPD project is a collaboration between DESY, PSI, and the Universities of Bonn and Hamburg. The goal is a 1024 × 1024-pixel detector with a 200 μm pixel size and a central aperture for the primary beam. The ASIC operates in charge integration mode: the output of each pixel’s preamplifier is proportional to the charge generated by the X-rays on the sensor. The input stage of the pixel cells uses dynamically adjustable gains. The output signal is stored in an analog memory, which must strike a balance between noise performance and the number of images. This memory operates in random access mode, allowing bad frames to be overwritten for optimal use of the 352 memory cells per pixel, which must be read out and digitized within the 99.4 ms bunch gap. The detector will consist of 8 × 2 fully depleted monolithic silicon sensors with an 8 × 2 array of CMOS readout chips bump-bonded to them. Several prototypes of the readout ASIC have been produced. The results presented originate from the 16 × 16-pixel matrices AGIPD 0.2, which was bump-bonded to a pixel sensor, and AGIPD 0.3, which includes the intended control algorithm and a fast differential interface to the off-chip world.</p>
References and Relationships
DOI 10.1109/nssmic.2011.6154392
Keywords
2D detector
Application specific integrated circuits
Hybrid Pixel Detector
XFEL