Medical Definition of Beta limit
1.
if the plasma pressure in a tokamak becomes too high, the so-called ballooning modes become unstable and lead to a loss of confinement (sometimes catastrophic, sometimes not). The exact value at which this occurs depends strongly on the magnetic field B, the plasma minor radius a, and the toroidal plasma current I, such that maximum value of the normalised beta, beta_N=betaBa/I, is around 4% (with B in Teslas, a in metres, and I in Mega-amperes). The exact value depends on details of the plasma shape, the plasma profiles, and the safety factor.
Synonym: troyon limit.
(09 Oct 1997)
Lexicographical Neighbors of Beta Limit
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