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The AGIPD (adaptive gain integrating pixel detector) detector is a high frame rate (4.5 MHz) and high dynamic range (up to 10 4 ·12.4 keV photons) detector with single photon resolution (down to 4 keV taking 5 σ as limit and lowest noise settings) developed for the European XFEL (XFEL.EU). This work is focused on the characterization of AGIPD1.0, which is the first full scale version of the chip. The chip is 64×64 pixels and each pixel has a size of 200×200 μm 2 . Each pixel can store up to 352 images at a rate of 4.5 MHz (corresponding to 220 ns). A detailed characterization of the AGIPD1.0 chip has been performed in order to assess the main performance of the ASIC in terms of gain, noise, speed and dynamic range. From the measurements presented in this paper a good uniformity of the gain, a noise around 320 e − (rms) in standard mode and around 240 e − (rms) in high gain mode has been measured. Furthermore a detailed discussion about the non-linear behavior after the gain switching is presented with both experimental results and simulations. [ABSTRACT FROM AUTHOR]

The INFN PixFEL project is developing the fundamental building blocks for a large area X-ray imaging camera to be deployed at next generation free electron laser (FEL) facilities with unprecedented intensity. Improvement in performance beyond the state of art in imaging instrumentation will be explored adopting advanced technologies like active edge sensors, a 65 nm node CMOS process and vertical integration. These are the key ingredients of the PixFEL project to realize a seamless large area focal plane instrument composed by a matrix of multilayer four-side buttable tiles. In order to minimize the dead area and reduce ambiguities in image reconstruction, a fine pitch active edge thick sensor is being optimized to cope with very high intensity photon flux, up to 10 4 photons per pixel, in the range from 1 to 10 keV. A low noise analog front-end channel with this wide dynamic range and a novel dynamic compression feature, together with a low power 10 bit analog to digital conversion up to 5 MHz, has been realized in a 110 μm pitch with a 65 nm CMOS process. Vertical interconnection of two CMOS tiers will be also explored in the future to build a four-side buttable readout chip with high density memories. In the long run the objective of the PixFEL project is to build a flexible X-ray imaging camera for operation both in burst mode, like at the European X-FEL, or in continuous mode with the high frame rates anticipated for future FEL facilities. [ABSTRACT FROM AUTHOR]

Abstract: A review of the parameters of the AGIPD detector planned to be used on the SASE 1 and SASE 2 beamlines of the European XFEL is presented. For both Coherent X-ray Diffraction Imaging (CXDI) and X-ray Photon-Correlation Spectroscopy (XPCS), the required detector noise level and dynamic range are evaluated from signal and background simulations on a per instrument basis. A worst case scenario of accumulated dose is computed in order to evaluate the required detector radiation hardness. Finally, acknowledging a mismatch between pixel size requirement and technological feasibility in the case of XPCS, the possibility to aperture the pixel in order to match the size requirement is presented and discussed. [Copyright &y& Elsevier]

Since the introduction of the extremely intense X-ray free electron lasers, the need for low noise, high dynamic range and potentially fast charge integrating detectors has increased significantly. Among all the problems that research and development groups have to face in the development of such detectors, their calibration represents one of the most challenging and the collaboration between the detector development and user groups is of fundamental importance. The main challenge is to develop a calibration suite that is capable to test the detector over a wide dynamic range, with a high granularity and a very high linearity, together with a certain radiation tolerance and the possibility to well define the timings and the synchronization with the detector. Practical considerations have also to be made like the possibility to calibrate the detector in a reasonable time, the availability of the calibration source at the experimental place and so on. Such a calibration test suite is often not represented by a single source but by several sources that can cover different parts of the dynamic range and that need to be cross calibrated to have a final calibration curve. In this respect an essential part of the calibration is also to develop a mathematical model that allows calibrating the entire dynamic range, taking into account features that are calibration source and/or detector specific. The aim of this contribution is to compare the calibration for the AGIPD detector using several calibration sources such as internal current source, backside pulsing, IR pulsed laser, LED light and mono-energetic protons. The mathematical procedure used to calibrate the different sources will be discussed in great detail showing how to take into account a few shortcomings (like pixel coupling) that are common for many charge integrating detectors. This work has been carried out in the frame of the AGIPD project for the European X-ray Free Electron Laser. [ABSTRACT FROM AUTHOR]

AGIPD, the Adaptive Gain Integrating Pixel Detector, is a hybrid detector with a frame rate of 4.5 M H z , a dynamic range up to 1 0 4 ⋅ 12.4 k e V photons, as well as single photon resolution, developed for the European XFEL (Eu.XFEL). The final 1 Mpixel detector system consists of 16 tiled modules each one with 16 readout chips. The single ASIC is 64 x 64 pixels, each with a size of 200 x 200 μ m 2. Each pixel can store up to 352 images. This work is focused on the characterization of AGIPD1.1, the second version of the full scale ASIC, and the improvements with respect to AGIPD1.0. From the measurements presented in this paper we show that the flaws observed in AGIPD1.0 (i.e. ghosting, crosstalk, slow readout speed) have been fixed in AGIPD1.1. In addition the main performance parameters such as noise, dynamic range and so on were measured for the new version of the ASIC and will be summarized. [ABSTRACT FROM AUTHOR]