Thermal Stability of Pure and Catalyzed D-D Fusion Reactor Plasmas

Abstract

The thermal stabilities of the D-D fusion reactor plasmas operating on the pure- deuterium and the catalyzed-deuterium cycles have been analyzed by the first-order perturbation method in order to make clear the steady-state operating conditions. When the constant or trapped-ion mode scaling of the confinement-time is used, the critical temperature of the self-heated plasma lies in the vicinity of the minimum point for the confinement parameter nτ. Bohm scaling gives the lowest value for the critical temperature, while neo-classical scaling does the highest one. With increasing fuel injection energy, the growth rate of the instability at low temperature decreases, whereas it does not always decreases at high temperature. In the D-D fusion plasma, the subsidiary reaction 3He(d, p)4 He makes dominant contribution to the plasma heating and the instability at low temperature. The cyclotron radiation, the dominant power loss mechanism at high temperature, plays a significant role in determining the critical temperatures. Calculations neglecting the cyclotron radiation yield the inadequate, considerably higher values for them. The validity of the above results has been confirmed by the non-linear dynamic simulations.