ON THE STABILITY LIMITS OF THE PINCH CONDUCTOR CURRENT RATIO IN EXTRAP
A first attempt is made to take the special stability features of the Extrap confinement scheme into account, thereby including kinetic large Larmor radius (LLR) effects. This approach predicts Extrap to be unstable outside a domain defined by a lower and an upper ratio =a/a-"rm x" between the average pinch radius =a and the axial x-point distance a-"rm x" of the magnetic separatrix. The ratio =a/a-"rm x" is related to the ratio J-"rm p"/J-"rm v" between the pinch current J-"rm p" and the conductor current J-"rm v". Stability within the predicted domain seems to agree with so far performed linear and toroidal experiments, and can explain the observed increase in J-"rm p"/J-"rm v" and in the plasma temperature, in terms of an increased ratio =a/a-"rm x". According to present analysis, an optimum value of the conductor current J-"rm v" should further exist with respect to pinch equilibrium and stability, as given by the condition =a simeq a-"rm x".
Bibliographic Reference: REPORT TRITA-PFU14-87, AVAILABILITY: THE ROYAL INSTITUTE OF TECHNOLOGY, STOCKHOLM 1987
Record Number: 1989126086300 / Last updated on: 1989-05-01
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