Speaker
Dr
Christine HOA
(CEA Grenoble)
Description
The JT-60SA project is a combined project of the Japanese and European Satellite Tokamak Programme under the Broader Approach Programme. The tokamak will be operated in 2015 in Japan and will support ITER exploitation and research towards DEMO. This tokamak is currently in the conception design phase.
The cryogenic system of JT60-SA is designed to provide supercritical helium at 4.5 K, to cool down the superconducting magnets, their structures and cryopumps. The equivalent refrigeration capacity at 4.5 K will be around 11 kW (including thermal shields at 80K and current leads at 50K) and has to be optimised for different operation modes:
During the day, the refrigerator has to cope with the pulsed heat loads due to the heating of the plasma reactions. The peak heat loads can increase up to 40% of the average power. During the night, the tokamak is under holding operation mode and the heat loads are highly reduced.
The operation under pulsed heat loads can be critical for the refrigeration and the cryogenic devices, which cannot accept large variations in time. The presentation will focus on the different solutions for smoothing the heat loads, such as the use of a thermal buffer tank and the controls on cryogenic components in order to regulate the helium mass flow rate and to maintain a stable operation of the refrigerator. The design of the cryogenic system will be addressed taking advantage of the day/night cycles, in order to reduce the investment costs.
| Proposed for workshop session (see call for abstracts): 1- Operation 2- Maintenance 3 - Safety 4 - Control | operation |
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Author
Dr
Christine HOA
(CEA Grenoble)
