GT Readout — A development platform for 1 MHz frame-rate detectors at LCLS-II

Abstract The advances in X-ray Free Electron Lasers, such as LCSL-II, push the required performance of the detectors towards higher frame rates due to the higher repetition rates of the lasers. At SLAC National Accelerator Laboratory we are developing novel detectors to reach this performance in a phased approach, starting from ePixHR detectors operating at 5 kHz, then ePixUHR detectors operating from 35 kHz and 100 kHz, and finally the SparkPix family reaching all the way to 1 MHz by utilizing a sparse readout scheme. For the development of these latter ePixUHR and SparkPix detectors we propose a new readout platform called GT Readout where different sensors, ASICs, firmware and software can be tested on a common hardware platform. This platform enables the control of SLAC-designed ASICs, the clocking and data readout using gigabit transceivers, synchronization with the LCLS-II timing system via an optical fiber link and to use these detectors in air and in vacuum with a mechanical system that actively cools the components. In this paper we describe each of the aforementioned subsystems and provide initial system stability measurements. We also present results of the readout platform being used at one of the LCLS-II experimental hutches during the characterization of the ePixUHR detector at 35 kHz.