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Space Telescope Imaging Spectrograph
STIS-21

ACTIVITY TITLE: FUV-MAMA Optical Format Verification

ID: STIS-21

APPLICABLE SMOV REQUIREMENTS: L.10.4.5.3.3

DESCRIPTION: For each FUV-MAMA spectral optical element in the MSM (G140L, G140M, E140M, E140H), a LINE lamp spectrum will be taken to match selected observations that were done as part of the cycle 11 STIS/CAL program 9618. The new observations need only be done for one CENWAVE value of each grating. These observations will verify the optical paths and MSM positioning used for each of these modes, and will also allow a check of the spectral resolution. The normal monthly MSM offsetting should be turned off and the zero-offset MSM positions should be used for these observations.

IMPLEMENTATION METHOD: Stored commanding

DEPENDENCIES: Should occur no sooner than 36 hours after STIS-17 (FUV-MAMA HV Recovery) has been completed.

DURATION: 60 minutes (two 1800 s internal visits)

DATA REQUIREMENTS: 268 Mbits.

ANALYSES & EXPECTED RESULTS: For each lamp spectrum obtained, compare the position of the spectral lines and the locations masked by the aperture bars to corresponding observations from program 9618. Look for any unexpected or operationally significant shifts in how the spectrum is projected onto the detector. Also, compare the line profiles for selected spectral lines to check for any changes in spectral resolution or focus across the detector. Look especially for any changes that are significant enough to affect operations or science data quality, or which might require table or database updates.

COMMENTS: We plan to choose a subset of CENWAVE settings that also match those used for the initial alignment checks done during SMOV2 by program 7078. Suggested settings: G140M 1371 52X0.05 200s; G140L 52X0.05 300s; E140M 0.2x0.06 663s, E140H 1416 0.2X0.09 266s.

AUTHOR/telephone/email: Charles Proffitt/410-338-4938/proffitt@stsci.edu

DATE: September 10, 2007