Performance test of a ceramic rotor developed for turbomolecular pumps for fusion use

Journal Article · Wed Jul 01 00:00:00 EDT 1987 · J. Vac. Sci. Technol., A; (United States)

DOI:https://doi.org/10.1116/1.574393· OSTI ID:6488331

Murakami, Y; Abe, T; Morii, S; Nakaishi, N; Hata, S

Turbomolecular pumps with a metallic rotor have been widely used to pump out gases from plasma confinement devices. However, high magnetic fields produced by magnet coils and plasmas cause eddy current heating and rotation speed reduction of the rotor of the pumps, and as a result serious problems take place in the rotor strength and pump performance. In order to overcome these problems, the authors have been developing a ceramic turbomolecular pump and, as a first step, have manufactured a test machine. The test machine consists of a ceramic rotor assembly with high electrical resistivity, gas bearings, a gas turbine, and a spiral-groove seal. The ceramic material is silicon nitride. Using the material strength of the actual components, rupture probability of the rotor assembly was estimated at various rotation speeds. Rotational tests of the test machine were successfully performed in both stationary and pulsed magnetic fields (0.046 T and 0.02 T/ms, respectively) at the required speed of 30 000 rpm. The leak rate through the spiral-groove seal was measured for two different seal gaps and at various rotation speeds.

• Research Organization: Japan Atomic Energy Research Institute (JAERI), Naka Fusion Research Establishment, Naka-machi, Naka-gun, Ibaraki-ken, Japan
• OSTI ID: 6488331
• Journal Information: J. Vac. Sci. Technol., A; (United States), Vol. 5:4
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
THERMONUCLEAR DEVICES
TURBOMOLECULAR PUMPS
PERFORMANCE TESTING
ROTORS
CERAMICS
ROTATION
SILICON NITRIDES
EQUIPMENT
LABORATORY EQUIPMENT
MOTION
NITRIDES
NITROGEN COMPOUNDS
PNICTIDES
PUMPS
SILICON COMPOUNDS
TESTING
VACUUM PUMPS
700209* - Fusion Power Plant Technology- Component Development & Materials Testing