Line List for Calibration Lamps:

• Summary: The ST-ECF lamp project, funded directly by ESA, is dedicated to the study of hollow cathode calibration lamps as they are used onboard the HST.

  First, we have measured the spectra of Pt/Cr-Ne lamps in order to obtain accurate and reliable wavelengths for all emission lines between 115 and 320 nm. This wavelength range corresponds to the coverage provided by the STIS Echelle modes. Extensive laboratory measurements were performed at the National Institute of Standards and Technology (NIST) using their 10.7 m normal incidence spectrograph and a Fourier Transform Spectrograph. Until now no good laboratory wavelengths for Cr had been available and their addition has a major impact on the wavelength calibration, in particular in the near UV. The new line list is being used in conjunction with the physical instrument model of STIS which is employed to derive an improved wavelength calibration as part of the STIS-CE effort. Second, we attempt to gain a better understanding of the performance of such lamps and the physical processes involved in their long term operations. Among the issues studied are the change of the spectrum as a function of current, its change as a function of time and the tolerances of alignment. The bulk of the measurements were performed on flight spares from STIS and on new space qualified lamps for the accelerated aging test. The original flight lamps from the FOS and the GHRS are the only lamps ever to be measured after their return from space. Together with the spectra archived from six years of on-orbit operations they provide a unique data set for studying ageing effects in these lamps. Our findings also constitute important lessons for the design and operations of future UV and optical spectrographs in space.

• Documentation:

  -Characterization of the Far-Ultraviolet Spectrum of Pt/Cr-Ne Hollow Cathode Lamps as Used on the Space Telescope Imaging Spectrograph on Board the Hubble Space Telescope. Sansonetti, C. J., Kerber, F., Reader, J., & Rosa, M. R., ApJ Supp. (pdf)
  -Spectral Characterization of HST Calibration Lamps - New Pt/Cr-Ne line catalogues and ageing test; poster from SPIE Glasgow 2004
  -Characterization of Pt/Cr-Ne Hollow Cathode Lamps for Wavelength Standards in Space Astronomy; poster from Space Telescope Calibration Workshop, Baltimore 2005
  -Performance of the FOS and GHRS Pt/(Cr)-Ne Hollow Cathode Lamps After Their from Space and copmarison with Archival Data; poster from Space Telescope Calibration Workshop, Baltimore 2005
  -STIS Calibration Enhancement - Spectral Characterisation of Pt/Cr-Ne Hollow Cathode Lamps in the March 2003 ST-ECF Newsletter #33
  -STIS Calibration Enhancement - Two Unusual Visits to the Smithsonian National Air and Space Museum in the January 2004 ST-ECF Newsletter #35
  -STIS Calibration Enhancement - New Insights from the ST-ECF Lamp Project October 2004 ST-ECF Newsletter #37
  -See also the Atlas of the Spectrum of a Platinum Neon Hollow Cathode Lamp in the region 1130 Å to 4330 Å from NIST

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