Low Temperature Physics: 29, 472 (2003); https://doi.org/10.1063/1.1542531 (9 pages)
Физика Низких Температур: Том 29, Выпуск 6 (Июнь 2003), c. 637-647    ( к оглавлению , назад )

Short-range inverse-square law experiment in space

Donald M. Strayer

Jet Propulsion Laboratory, Caltech, 4800 Oak Grove Drive, Pasadena, CA 91109, USA
E-mail: dons@squid.jpl.nasa.gov

Ho Jung Paik and M. Vol Moody

Department of Physics, University of Maryland, College Park, MD 20742, USA

Received December 19, 2002


The objective of ISLES (inverse-square law experiment in space) is to perform a null test of Newton`s law on the ISS with a resolution of one part in 105 at ranges from 100 mm to 1 mm. ISLES will be sensitive enough to detect axions with the strongest allowed coupling and to test the string-theory prediction with R≥ 5 mm. To accomplish these goals on the rather noisy International Space Station, the experiment is set up to provide immunity from the vibrations and other common-mode accelerations. The measures to be applied for reducing the effects of disturbances will be described in this presentation. As designed, the experiment will be cooled to less than 2 K in NASA`s low temperature facility the LTMPF, allowing superconducting magnetic levitation in microgravity to obtain very soft, low-loss suspension of the test masses. The low-damping magnetic levitation, combined with a low-noise SQUID, leads to extremely low intrinsic noise in the detector. To minimize Newtonian errors, ISLES employs a near-null source of gravity, a circular disk of large diameter-to-thickness ratio. Two test masses, also disk-shaped, are suspended on the two sides of the source mass at a distance of 100 mm to 1 mm. The signal is detected by a superconducting differential accelerometer, making a highly sensitive sensor of the gravity force generated by the source mass.

04.20.-q - Classical general relativity (see also 02.40.-k Geometry, differential geometry, and topology)