Bench and thermal vacuum testing of the JUICE-UVS microchannel plate detector system

The JUICE (JUpiter ICy moons Explorer) Ultraviolet Spectrograph (JUICE-UVS) is the fifth in the line of Alice/UVS spectrographs from Southwest Research Institute (SwRI). The heart of the instrument is a far-UV sensitive microchannel plate detector system. This detector includes an atomic-layer deposition (ALD) coating on the bottom plate to minimize gain sag, resulting in a detector with orders of magnitude longer lifetime given comparable fluences than previously flown MCP detectors. This detector is also the first instance of a curved microchannel plate z-stack receiving an ALD coating to minimize gain sag. The detector electronics have also been improved over previous generations to preserve pulse height integrity at the high (i.e. 100 kHz) count rates expected during operation in the Jupiter system. The flight model detector was bench tested at Sensor Sciences and delivered to the JUICE-UVS project in August 2018. Further bench tests were undertaken at SwRI after delivery, followed by thermal vacuum testing in October 2018. The results of these tests are presented herein.