Development and Testing of High-Heat-Flux Components for the Tore Supra Horizontal Pump Limiter Module.

摘要

The actively cooled pump limiter module located at the horizontal midplane of the Tore Supra Tokamak is designed for 2 MW of steady state power removal. For a thin (2.5 cm thick) limiter head which maximizes pumping and particle removal, this power load results in surface heat fluxes near 30 MW/m sup 2 at the leading edge and 10 MW/m sup 2 for the front surface. The initial design configuration for the high-heat-flux surfaces consisted of pyrolytic graphite armor tiles brazed to alumina dispersion strengthened copper tubes. Subsequent finite element analyses and braze tests showed that direct bonding of the highly anisotropic pyrolytic graphite to the strong (400 MPa yield strength) copper alloy led to cracking in the pyrolytic graphite tiles and a significant reduction in heat removal capabilities. To eliminate the graphite cracking problem, various compliant interlayers between the copper tube and the armor tile were tried. Interlayers tested included OFHC copper and several types of copper feltmetal. The resulting brazes were evaluated with metallurgical laboratory techniques and by testing at design heat fluxes with the use of a rastered electron beam apparatus. This paper describes the development and testing effort which solved the brazing difficulties, and resulted in a design capable of meeting design goals. 7 refs., 5 figs. (ERA citation 13:058266)