Stabilization of Trapped-Particle Modes by Reversed-Gradient Profiles

Under certain modes of operation of very large tokamaks such as the proposed two-component torus (TCT), it is possible to create oppositely directed density and temperature gradients ($\nabla n·\nabla T<\mathrm{}0\mathrm{}$) in the hotter central region of the plasma and the usual profile ($\nabla n·\nabla T>\mathrm{}0\mathrm{}$) on the colder outer edge. Such configurations are found to be very favorable to stability against trapped-particle modes.