ISSN:
1089-7674
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The effectiveness of the pumped divertor during the 1994/95 experimental campaign of the Joint European Torus (JET) [P.-H. Rebut, R. J. Bickerton, and B. E. Keen, Nucl. Fusion 25, 1011 (1985)] has allowed the pursuit of a broad-based research program that is highly relevant to the International Thermonuclear Experimental Reactor (ITER) [K. Tomabechi and the ITER Team, Nucl. Fusion 31, 1135 (1991)]. High-performance hot-ion discharges with high confinement (H-modes) free of edge localized modes (ELMs) have set a JET record neutron rate in deuterium, but are limited by various magnetohydrodynamic (MHD) phenomena to βN〈1.8, where βN=β/(I/aB), β is the ratio of the plasma pressure to the toroidal field pressure, I is the plasma current, B is the toroidal field, and a is the horizontal minor radius of the plasma. Quasi-steady-state ELMy H-modes have also been studied at high power, high current, and high β. The underlying energy transport exhibits a gyro-Bohm dependence that is lost close to the H-mode threshold and at high β. ELMy H-modes with detached divertor plasmas and radiative power exhaust (the operating regime foreseen for ITER) reduce the power loading to the targets, but at the expense of main plasma confinement and purity. Beryllium has been compared with carbon fiber composite as a divertor target material and melting has been induced at ITER reference off-normal heat loads, but only a moderate degree of self-protection of the beryllium target was found. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.872028
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