TRL6 testing of a curved borosilicate glass microchannel plate far-UV detector assembly for spaceflight

The Europa Clipper Ultraviolet Spectrograph (Europa-UVS) is the sixth 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 consists of a z-stack of three borosilicate glass microchannel plates, with resistive and secondary emissive layers deposited via an atomic-layer deposition (ALD) process. The resulting detector has orders of magnitude longer lifetime given comparable fluences than previously flown MCP detectors, as well as reduced sensitivity to gamma-ray induced background noise. This detector is also the first instance of a curved borosilicate glass microchannel plate z-stack undergoing thermal vacuum testing in a flight-like environment, raising the TRL of the system to 6. The flight model detector was bench tested at Sensor Sciences and delivered to the Europa-UVS project in July 2020. Further bench tests were undertaken at SwRI after delivery, followed by thermal vacuum testing in December 2020. The results of these tests are presented herein.