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Measurement of Mercury Mass in the Deep Space Atomic Clocks (DSAC's) rf-Discharge Lamp

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[Technical Report, Technical Report]

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Using Differential Scanning Calorimetry DSC, we demonstrate an ability to measure mercury mass in Hg rf-discharge lamps used in space-qualified Hg atomic clocks. In particular, for a DSAC Hg lamp provided by JPL, we measure a mass of 205 15 micro-gms. We believe the mass uncertainty is low enough to allow us to perform Hg consumption studies on these lamps, and through those studies define minimum Hg fills for the lamps to ensure specified space-mission lifetimes. Additionally, we show that photographic images of Hg droplets can provide a rough means of estimating Hg mass in rf-discharge lamps.

Subject Categories:

  • Test Facilities, Equipment and Methods

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[A, Approved For Public Release]