MHD stable regime of the Tokamak

A broad family of Tokamak current profiles is found to be stable against ideal and resistive MHD king modes for 1<or=q(0), with q(a) as low as 2. For 0.5<or=q(0)<1 and q(a)>1, current profiles can be found that are unstable only to the m=1, n=1 mode. A specific 'optimal' Tokamak profile can be selected from the range of stable solutions, by imposing a common upper limit on dj/dr-corresponding in ohmic equilibrium to a limitation of dT₃/dr by anomalous transport.