A moving belt divertor concept
- Rensselaer Polytechnic Institute, Troy, NY (United States)
The primary concerns in the design of a divertor component are the high heat fluxes (15 to 30 MW/m[sup 2]) and the surface erosion due to plasma/wall interactions, along with the associated issue of plasma contamination. A continuous belt, which would pass between two rollers inside the vacuum vessel, is proposed as the divertor surface to provide higher heat flux handling capability as well as reduced total erosion. Thermal analyses indicate that a belt passing from one roller through the divertor region to a cooling roller can achieve a cycle-to-cycle steady state while maintaining acceptable temperatures. The belt speed determines the amount of plasma energy absorbed per cycle and thus determines the maximum belt temperature and the requirements of the cooling roller. The belt material initially considered is a metal matrix/carbon fiber composite in which the carbon fibers are oriented out-of-plane in a 1-mm-thick metal belt. The carbon fibers protrude from the plasma-facing side of the belt, presenting the plasma ions a low-Z surface to impact. Because the belt surface passes through the entire divertor region, the erosion due to sputtering is uniform along the belt. Estimated gross erosion rates for a 7-m belt at expected International Thermonuclear Experimental Reactor (ITER) conditions are 5 to 10 cm/burn-yr. Electromagnetic forces and secondary magnetic fields induced by the belt motion appear manageable for a sufficiently resistive or toroidally segmented belt. In situ deposition of a sacrificial carbon layer will be required to replace eroded material. Such a belt also offers the possibility of continuous removal of the plasma-codeposited carbon and tritium layer prior to deposition of the sacrificial carbon. 8 refs., 22 figs., 3 tabs.
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6751260
- Journal Information:
- Fusion Technology; (United States), Vol. 24:1; ISSN 0748-1896
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
DIVERTORS
DESIGN
EROSION
HEAT FLUX
ITER TOKAMAK
CARBON FIBERS
MATRIX MATERIALS
CLOSED PLASMA DEVICES
FIBERS
MATERIALS
THERMONUCLEAR DEVICES
THERMONUCLEAR REACTORS
TOKAMAK DEVICES
TOKAMAK TYPE REACTORS
700420* - Fusion Technology- Plasma-Facing Components- (1992-)