JET pump limiter
It is planned to install two pump limiter modules in JET, which can be used for belt-limiter, inner-wall and X-point discharges and also, for 1-2s, as the main limiter. A design is presented which is compatible with two diagnostic systems which otherwise might interfere, and allows partial removal of the pump limiter to provide access for remote-handling operations. The high heat-flux components are initially cooled during a pulse. Heat is removed between discharges by radiation and pressure contacts to a water-cooled support structure. The pumping edge will be made of annealed pyrolytic graphite, which material has been shown to sustain heat loads of 45MW/m2 for 1-2s. Exhaust efficiency has been estimated, for a l-d edge model, using a Monte-Carlo calculation of neutral gas transport. When the pump limiter is operated together with other wall components an efficiency of 5% (2.5 x 1.0 E21 part/s) is expected. As a main limiter the efficiency increases to about 10%.
Bibliographic Reference: Report: JET-R(88)10 EN (1988)
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 198910002 / Last updated on: 1994-12-01
Original language: en
Available languages: en