Preliminary Design of Readout Electronics for DCLS Gas Monitor Detectors

This paper presents the preliminary design and test of readout electronics for DCLS (Dalian Coherent Light Source) GMDs (Gas Monitor Detectors). DCLS is an FEL (Free-Electron Laser) at EUV (Extreme Ultraviolet) and operates at a maximum repetition frequency of 50 Hz. There are two beamlines and each one has been installed with two GMDs. GMDs are deployed to monitor the intensity of the EUV pulse by pulse from 0.1 μJ to 1 mJ online. The readout electronics consist of a self-designed preamplifier, an adapter board with a high-voltage filter, and a digitizer (1-GSPS oscilloscope). The preamplifier is near the detector plate and has two-stage amplifiers: a TIA (Trans-Impedance Amplifier) and a ratio phase amplifier. First-stage outputs for 10 μJ to 1 mJ FEL detection and second-stage for 0.1 μJ to 10 μJ, which makes digitizers work on high resolution. Preliminary results show that this readout electronics works properly. This paper can provide design references on other gas detectors’signal readouts.