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Proceedings Paper

Thermal metrology for a space-based gravity experiment
Author(s): Stephen W. Allison; W. S. Key; Michael R. Cates; David L. Beshears; Alvin J. Sanders; R. J. Newby; Jonathan W. Campbell; R. Greg Schunk
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Paper Abstract

A proposed space-based test of gravitational theory requires unique performance for thermometry and ranging instrumentation. The experiment involves a cylindrical test chamber in which two free-floating spherical test bodies are located. The test bodies are spheres which move relative to each other. The direction and rate of motion depend on the relative masses and orbit parameters mediated by the force of gravity. The experiment will determine Newton's gravitational constant, G; its time dependence, as well as investigate the equivalence principle, the inverse square law, and post- Einsteinian effects. The absolute value of the temperature at which the experiment is performed is not critical and may range anywhere from approximately 70 to 100 K. However, the experimental design calls for a temperature uniformity of approximately 0.001 K throughout the test volume. This is necessary in order to prevent radiation pressure gradients from perturbing the test masses. Consequently, a method is needed for verifying and establishing this test condition. The presentation is an assessment of the utility of phosphor-based thermometry for this application and a description of feasibility experiments. Phosphor thermometry is well suited for resolving minute temperature differences. The first tests in our lab have indicated the feasibility of achieving this desired temperature resolution.

Paper Details

Date Published: 1 October 1997
PDF: 8 pages
Proc. SPIE 3116, Small Spacecraft, Space Environments, and Instrumentation Technologies, (1 October 1997); doi: 10.1117/12.293328
Show Author Affiliations
Stephen W. Allison, Oak Ridge National Lab. (United States)
W. S. Key, Oak Ridge National Lab. (United States)
Michael R. Cates, Oak Ridge National Lab. (United States)
David L. Beshears, Oak Ridge National Lab. (United States)
Alvin J. Sanders, Univ. of Tennessee/Knoxville (United States)
R. J. Newby, Univ. of Tennessee/Knoxville (United States)
Jonathan W. Campbell, NASA Marshall Space Flight Ctr. (United States)
R. Greg Schunk, NASA Marshall Space Flight Ctr. (United States)

Published in SPIE Proceedings Vol. 3116:
Small Spacecraft, Space Environments, and Instrumentation Technologies
Firooz A. Allahdadi; Firooz A. Allahdadi; Timothy D. Maclay; E. Kane Casani; Timothy D. Maclay, Editor(s)

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