What this work contributes
Finds that a nearby enclosure can increase residual-gas damping and associated force noise. Two different torsion-pendulum arrangements and numerical modeling demonstrate why chamber geometry belongs in the measurement model.
Where the evidence stops
The enhancement depends on clearance, geometry and gas conditions. The paper does not prescribe one universal vacuum pressure or correction factor for every balance.
Keep the conditions with the result
- Measured / modeled quantity
- Residual-gas damping and Brownian force-noise power
- Reported scale
- For the analyzed LISA geometry, force-noise power was about 15 times the infinite-volume estimate.
- Conditions
- Macroscopic test masses near enclosure walls in the molecular-flow regime.
- Evidence context
- Two torsion-pendulum geometries compared with simulations; no independent replication claim made here.
- Design use
- Assess sensor-to-wall clearance and pressure dependence when designing a vacuum enclosure.
- Review access
- Publisher abstract and bibliographic details checked; full text not reviewed.
Original source
A. Cavalleri, G. Ciani, R. Dolesi, A. Heptonstall, M. Hueller, D. Nicolodi, S. Rowan, D. Tombolato, S. Vitale, P. J. Wass, W. J. Weber. Increased Brownian Force Noise from Molecular Impacts in a Constrained Volume. Physical Review Letters 103, 140601 (2009).
DOI: 10.1103/PhysRevLett.103.140601
How we use it
This record belongs to Measurement & replication. Its evidence label describes the cited work, not the maturity of a Metric Flight device. Follow the original methods, corrections and conditions before transferring a result to a different geometry or scale.
Editorial note reviewed 19 October 2026. AI assisted research discovery and synthesis. Citation metadata and claims were checked against primary publication or institutional records; full-text access varies. Read the source for the complete method.