The residual gas damping of the test mass (TM) in the free molecular flow
regime is studied in the finite open systems for high-precision gravity-related
experiments. Through strict derivation, we separate the damping coefficients
for two finite open systems, i.e., the bi-plate system and the sensor core
system, into base damping and diffusion damping. This elucidates the
relationship between the free damping in the infinite gas volume and the
proximity damping in the constrained volume, unifies them into one microscopic
picture, and allows us to point out three pathways of energy dissipation in the
bi-plate gap. We also provide the conditions that need to be met to achieve
this separation. In applications, for space gravitational wave detection, our
results for the residual gas damping coefficient for the 4TM torsion balance
experiment is the closest one to the experimental and simulation data compared
to previous models. For the LISA mission, our estimation for residual gas
acceleration noise at the sensitive axis is consistent with the simulation
result, within about $5%$ difference. In addition, in the test of the
gravitational inverse-square law, our results suggest that the constraint on
the distance between TM and the conducting membrane can be reduced by about
$28%$.
The article examines the residual gas damping in finite open systems for high-precision gravity-related experiments. Through a strict derivation, the damping coefficients for the bi-plate system and the sensor core system are separated into base damping and diffusion damping, revealing the relationship between free damping and proximity damping. This microscopic picture allows for the identification of three pathways of energy dissipation in the bi-plate gap, and conditions are provided for achieving this separation.
For space gravitational wave detection, the article’s results for the residual gas damping coefficient in the 4TM torsion balance experiment align closely with experimental and simulation data compared to previous models. In terms of the LISA mission, the estimation for residual gas acceleration noise at the sensitive axis is consistent with simulation results, with only a 5% difference. Additionally, in the test of the gravitational inverse-square law, the article suggests a potential reduction of about 28% in the constraint on the distance between TM and the conducting membrane.
Future Roadmap
Challenges
- Further validation: The conclusions drawn from this study need to be validated through experimental data and simulations to ensure their accuracy and applicability across different scenarios.
- Improved measurement techniques: Developing more precise measurement techniques will be crucial in further exploring and understanding residual gas damping in gravity-related experiments.
- Reducing external interference: Efforts should be made to minimize external factors that could introduce noise or affect the accuracy of measurements related to residual gas damping.
Opportunities
- Enhanced gravitational wave detection: By understanding and minimizing residual gas damping, there is an opportunity to improve the sensitivity and accuracy of gravitational wave detection systems.
- Optimized mission design: The estimation of residual gas acceleration noise provided by this study can aid in the design and planning of future missions like LISA, enabling better performance and more reliable results.
- Advancements in fundamental physics tests: With the potential reduction in the constraint on the distance between TM and the conducting membrane, there is an opportunity to further investigate and test the gravitational inverse-square law with increased precision.
In conclusion, this article provides valuable insights into the study of residual gas damping in finite open systems. The separation of damping coefficients and the identification of energy dissipation pathways contribute to a better understanding of this phenomenon. The potential challenges and opportunities on the horizon indicate the need for further research and development in order to maximize the benefits of this knowledge in various gravity-related experiments.