Cryogenic Balance

Our best balances are limited by the thermal noise (Brownian motion) in the torsion fiber. To achieve improved performance, we have built a new balance which is cooled to ~5 K by a pulse tube refrigerator and housed in multiple layers of magnetic and thermal shielding, including a layer of superconducting lead. Further development of noise reduction is ongoing.

Cryogenic balances may allow improved tests of short-range gravitational interaction and new spin dependent interactions, in addition to future Equivalence Principle measurements.