On-orbit performance of the double delay line detectors for the Far Ultraviolet Spectroscopic Explorer

摘要

The Far Ultraviolet Spectroscopic Explorer (FUSE) satellite was launched into orbit on June 24, 1999. FUSE is designed to make high resolution (λ/Δλ = 20,000 - 25,000) observations of solar system, galactic, and extragalactic targets in the far ultraviolet wavelength region (905 -1187 A). Its high effective area, low background and planned three year life allow observations of objects which have been too faint for previous high resolution instruments in this wavelength range. The FUSE instrument includes two large format microchannel plate detectors. Each detector system consists of two microchannel plate segments in a Z-stack configuration with double delay line anodes and associated electronics. High detector spatial resolution was required in order to obtain scientific data with high spectral resolving power, and low detector background was necessary in order to observe faint objects. We describe the performance of the FUSE detectors during their first year on orbit, including the mechanical and thermal stability, throughput, background, and flat field of the detector system. We will also discuss the regular single event upsets of the detector electronics, and the strategy adopted in order to minimize their impact on mission efficiency.