Long-term gain variation in the FUSE detectors

摘要

The Far Ultraviolet Spectroscopic Explorer (FUSE) satellite has been in orbit and collecting scientific data since mid-1999. The FUSE detector system contains two large-format microchannel plate detectors with double delay line anodes. Both detectors have performed well since the beginning of the mission, but as they have aged their gain characteristics have changed. Variations in the amount of charge extracted as a function of position on the detector has caused time- and wavelength-dependent changes to the detector performance; corrections for these effects must be applied to the data in the science data pipeline in order to minimize the introduction of artifacts into the calibrated spectra. The gain characteristics of the detectors and the ways in which they have changed since launch are discussed, as are mitigation strategies in both the use of the detectors and the interpretation of the data.