Low-power readout electronics for microchannel plate detectors with cross strip anodes

The World Space Observatory - Ultraviolet (WSO-UV) will be the only space telescope for the ultraviolet wavelength range between 102 and 310 nm during the next decade. It is a multinational project under Russian leadership with contributions from Ukraine and Spain. Its main instrument, the WSO-UV Spectrographs (WUVS), was designed by IAAT in collaboration with the Leibniz Institut fur Analytische Wissenschaften, Berlin. We are developing the corresponding microchannel plate detectors using new combinations of materials for the photocathode as well as a 64 by 64 cross strip anode for event position determination. Charge pre-amplification is performed by the Beetle chip designed at the ASIC laboratory of the MPIK for LHCb at CERN. It has 128 pre-amplifiers on one die and provides the analog output in a four-fold serial stream. This stream is digitized by four ADCs and processed in a Microsemi RTAX FPGA. Processed data are sent to the instrument control unit via a SpaceWire interface. This concept results in one order of magnitude reduced power consumption in comparison to the use of conventional pre-amplifiers as well as a reduced volume, weight and complexity of the readout electronics. This paper presents the architecture of the electronics and details of the FPGA design as well as an estimation of the performance of our setup.