Potential for D-³He Experiments in Next-Generation Tokamaks

The potential for D-³He experiments in the proposed Compact Ignition Tokamak (CIT) and International Thermonuclear Experimental Reactor (ITER) tokamak test devices is examined. In CIT, an energy multiplication Q of ∼0.3 can be obtained with an injection power of ∼100 MW. Without modifications to ITER, except for the change of fuel, it is found that Q of the order of 0.3 to 0.5 can be obtained. Breakeven with D-³He requires modification to the device to increase the elongation to 2.4, reduce the major radius to 5.6 m, and increase the magnetic field at the plasma from 4.9 to 5.6 T. Operation with a small amount of tritium seeding can reduce the auxiliary power required to achieve breakeven and leads to Q = 2 in an unmodified device.