ISSN:
1572-9591
Keywords:
ripple transport
;
burn control
;
fusion reactor
;
INTOR
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract Under conditions representative of ignited tokamak operation, ion energy losses are likely to be dominated by transport due to deviation from toroidal field axisymmetry. This asymmetry, termed ripple, induces several distinct physical processes, all of which lead to enhanced ion thermal conduction above the neoclassical value. The net impact of these processes on ignition dynamics is analyzed for an INTOR-like plasma by means of a 1 1/2-D transport code. The radial shift of the plasma to regions of higher ripple during plasma heating results in a substantial broadening of the “window” of values of ripple consistent with favorable ignition and burn characteristics and also provides some measure of automatic burn control. Becauseβ-limiting processes are also prime candidates for burn control, the profiles obtained from the transport analyses are examined for stability with respect to ideal MHD modes. The MHD-limitedβ value increases as the plasma is heated and in fact in the burn phase approaches the value characteristic of a shape-optimized MHD equilibrium. The sensitivity of the transport and MHD results to the choice of plasma density is examined, and it is found that hot-ion mode operation is precluded for devices such as INTOR unless present estimates of both ripple losses andβ-limits are highly pessimistic.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01054578
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