Observations of Pt/Ne hollow cathode lamps similar to those used on the cosmic origins spectrograph: photometry and vacuum testing

We report accelerated vacuum aging te sts on two Pt-Ne lamps identical and /or similar to those installed onthe Cosmic Origins Spectrograph (COS) to be installed in the Hubble Space Telescope (HST) in the fall of2008. One additional lamp was aged in air at the National Institute of Standards and Technology (NIST). Alllamps were tested at a 50% duty cycle (30 s on/o) at ”ight nominal (10 mA) constant current until failure.Calibrated spectra of all lamps were taken at NIST using the 10.7-m normal incidence vacuum spectrograph atvarious points in the life of the lamps. In this paper we report the results of the photometric, electrical, andthermal monitoring of the vacuum tested lamps, while the spectroscopic and air aging results are given in acompanion paper (Nave et al. , 2008, SPIE 7011-134). We conclude that the lamps will satisfy the requirementsof the HST/COS mission in terms of lifetime, cycles, and thermal and spectral stability.Keywords: Cosmic Origins Spectrograph, vacuum ultraviolet, hollow cathode lamps, wavelength calibration,Hubble Space Telescope