THE VACUUM SYSTEMS OF THE NUCLEAR FUSION FACILITY JET
This review article describes the two most important vacuum systems of JET, namely the toroidal main vacuum vessel (Torus) and the cryopumps for the neutral beam injectors. The Torus (200 m**3 volume) is all welded, the vacuum system is all metallic and bakeable. The Torus inner wall (1000 m**2 surface) is bakeable to 500 degrees C and further conditioned by glow discharge cleaning. The Torus is operated at 300 degrees C and has a total impurity pressure of typically 4 x 10**-9 mbar. The Torus inner wall is routinely carbonized in order to reduce the influx of metallic impurities into the plasma. Future materials of plasma limiters and inner wall will be either beryllium or graphite. The LHe cryopump provides a pumping speed of 8 x 10**6 1/s for hydrogen from 40 m**2 pump entrance area. The pump design, the applied manufacturing technologies and operational data are given.
Bibliographic Reference: WRITE TO THE PUBLICATIONS OFFICER, JET JOINT UNDERTAKING, ABINGDON, OXON, OX14 3EA (UK), MENTIONING REPORT JET-P(86)08, 1986
Record Number: 1989124134200 / Last updated on: 1987-01-01
Available languages: en