ITER in perspective

The current International Thermonuclear Experimental Reactor (ITER) design features a 6-m major radius, a 2.15-m minor radius, and a 22-MA plasma current. About 330 V-s in the poloidal field system inductively drive the current for hundreds of seconds. About 125 MW of neutral-beam, lower-hybrid, and electron-cyclotron power are provided for steady-state current drive and heating. Because the ITER design must account for the fact that the tokamak database is not exact, a reasonably cautious approach must be taken. There are some benefits of such an approach: the chances of success are enhanced, ITER traverses most of the distance toward the size and power of a commercial reactor, and it may be capable of more performance than promised. By extending the operating rules to the maximum expected range, the fusion power may be increased such that the machine might be capable of simulating a small net energy condition. If so, then considerable progress could be made toward fusion-power applications