Preliminary characterization of a MCP photon counting detector prototype based on a custom-developed readout ASIC

Microchannel plates-based detectors have been for a long time the detectors of choice for astronomical applications in the FUV/EUV, due to their photon counting capability and the possibility of solar blindness. In the framework of technological R&D for a future astronomical FUV/EUV spectrograph, we are developing a new readout system to allow unprecedented dynamic range. The goal is to realize a photon counting, solar blind, UV detector, based on a MCP read out with a 2D anode array integrated in a custom designed Read Out Integrated Circuit (MIRA: Microchannel plate Readout ASIC), able to reach unprecedented performance in terms of dynamic range combined with spatial resolution close to 30μm. Each pixel contains an anode to collect the electrons emitted by the MCP, a low noise amplifier and filter to maximize the SNR, a comparator to recognize and count single photon events, logic to correct for charge sharing among pixels (CSCL) and two counters. Some preliminary characterization of the first prototype, based on a demonstrator of the MIRA ASIC, 32×32 pixels, 35×35μm² size, for a total chip area of 2×2mm², integrated into a standard demountable MCP intensifier, have been carried out.