Abstract: A wide variety of ultraviolet detectors are used aboard the Solar and Heliospheric Observatory (SOHO) spacecraft. The ultraviolet instrument package aboard SOHO includes one full disk EUV flux monitor (SEM: 30.4 nm), one full sky mapper (SWAN: 121.6 nm), one full-Sun imager (EIT: 17.1 - 30.4 nm), and three spectrometers (CDS: 15.1 - 78.5 nm; SUMER: 66.0 - 161.0 nm; UVCS: 93.7 - 136.1 nm). All wavelengths are first order. In total, there are fifteen UV detectors aboard SOHO with six distinctly different designs. These range from photodiodes, through backside-thin CCDs, to two-dimensional microchannel-plate detectors. Some instruments measure an analog signal (such as the charge deposited in a CCD well), while others measure single photon events. The intense brightness of the Sun imposes unique challenges on these astronomical detectors. After almost three years of continuous observation in space, a large body of data has been gathered on their performance. How well each detector system has performed over this period is examined in turn. !13
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