The development of an in-vessel cryopump system for the DIII-D tokamak
- General Atomics, San Diego, CA (United States)
- Oak Ridge National Lab., TN (United States)
The design, testing and initial operation of the DIII-D advanced divertor cryocondensation pumping system is presented. The pump resides inside the tokamak plasma containment vessel where it provides particle exhaust pumping, and it is subjected to Joule heating and hot particle heat loads during each 10 second discharge. In addition, the pump must withstand plasma disruption induced electromagnetic forces and 400{degrees}C bake-out temperatures. Cooling is accomplished by forced flow liquid helium with the two-phase helium exhaust passing through a reliquefier for thermal efficiency. A prototype pump was constructed to study surface temperature rise as a function of flow geometry, applied heat load, helium mass flow rate, and pump outlet conditions. Prototype testing led to the development of a special geometry which was demonstrated to enhance two-phase flow stability and overall heat transfer. During initial operation, deuterium pumping speeds of 32,000 L/s at 2 mTorr pressure were achieved with a helium flow rate of 5 g/s. This speed was maintained during 300 W, 8 s long test heat pulses which meets operational goals.
- DOE Contract Number:
- AC03-89ER51114; AC05-84OR21400
- OSTI ID:
- 47819
- Report Number(s):
- CONF-930703-; TRN: 95:011348
- Resource Relation:
- Conference: International cryogenic materials conference (ICMC), Albuquerque, NM (United States), 12-16 Jul 1993; Other Information: PBD: 1994; Related Information: Is Part Of Advances in cryogenic engineering, Volume 39, Part B; Kittel, P. [ed.]; PB: 1053 p.
- Country of Publication:
- United States
- Language:
- English
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