Integration, alignment, and initial performance results of the far ultraviolet spectroscopic explorer (FUSE) spectrograph

The Center for Astrophysics and Space Astronomy (CASA) recently delivered to the Johns Hopkins University the Far Ultraviolet Spectrograph instrument for integration into the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. In addition to the optical design of the FUSE instrument, the CASA/FUSE team was responsible for development of major optical components of the spectrograph and the final assembly and alignment of the instrument. In this paper we present the optical design, alignment methodologies employed, and performance characteristics of the instrument as delivered to the Johns Hopkins University. In addition, we discuss how we determined the resolution of the instrument and the difficulties in determining the resolving power when working with an FUV instrument capable of resolving powers in excess of 30,000. We also discuss the contamination control and monitoring and stability testing of the instrument, i.e. vibration, thermal distortion, and long term (12 hour) stability testing.