Accession Number:

AD1112550

Title:

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

Descriptive Note:

[Technical Report, Technical Report]

Corporate Author:

AEROSPACE CORP

Personal Author(s):

• Klimcak, Charles
• Huang, Michael
• Camparo, James

Report Date:

2019-09-01

Pagination or Media Count:

11

Abstract:

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.

Descriptors:

• jet propulsion
• phase transformations
• transition temperature
• heat energy
• failure mode and effect analysis
• measurement
• military research
• thermodynamics
• latent heat
• space systems
• atomic clocks
• deep space
• discharge lamps
• heat transmission
• melting
• standards
• transitions
• images
• metals
• photographic images

Subject Categories:

• Test Facilities, Equipment and Methods

Distribution Statement:

[A, Approved For Public Release]