THE THERMODYNAMIC HIERARCHY OF THE MAGNETIC EQUILIBRIA - RFP VS TOKAMAK
We have searched for the most probable equilibria in an axially symmetric toroidal geometry. We have found two solutions of maximum entropy under the constraints of fixed thermal energy and given geometry. One solution is only approximate and corresponds to a Tokamak, the other is rigorous and corresponds to a force free configuration. The best Tokamak from the thermodynamic point of view has a large aspect ratio, a circular cross sections and a poloidal beta near to 3, but is only a relative (and approximate) maximum of the entropy. The force free equilibrium with a minimum alpha**2 (where * = alpha*) is an absolute maximum of the entropy in the class of the magnetic Vlasov equilibria and is also a maximum with respect to the dissipative decay of the magnetic energy, provided that K = ** times *dV is conserved at first order.
Bibliographic Reference: WRITE TO ISTITUTO DI FISICA DEL PLASMA, VIA BASSINI 15, 20133 MILANO (ITALY), MENTIONING REPORT FP 83/11, 1983
Record Number: 1989122050100 / Last updated on: 1987-01-01
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