THE THEORY OF THE ROTATING-DISC VACUUM GAUGE

The rarefied gas dynamic of momentum transfer from a spinning disc to a stationary coaxial parallel disc is considered in the absence of molecular collisions with a surface tangential momentum accommodation coefficient of unity. The analysis is performed for the case of low and high rotation speeds, with an approximation derived for the intermediate case. Analytical studies are complemented by simulation using a Monte Carlo technique to give accurate results throughout the domain. The results are in excellent agreement with detailed experiments. It is concluded that the resulting rotating disc vacuum gauge can be used as an absolute instrument for measuring pressure in high vacua.