Fig. 2-3 Progress of large tokamak experiments The best JT-60 data obtained in autumn 1996 are shown together with the progress of JT-60 experiments over several years. Also shown are the typical results of JET (EU) and TFTR (USA). Both the break-even and the self-ignition conditions depend on the plasma density and temperature distribution as shown above.

In autumn of 1996 we achieved our target, the break-even plasma condition, in a series of deuterium plasma experiments on JT-60. We produced deuterium plasmas exhibiting the QDT =1 condition, where the fusion output power just balances the external heating input power, in a plasma composed of a 50-50 mixture of deuterium and tritium. The experiments were done with a negative magnetic shear confining field (Fig. 2-2), and other results of the experiments indicate that the plasma confined in the negatively-sheared magnetic field has several characteristics that will be favorable for a future steady-state tokamak fusion reactor. The best data obtained were a confinement time of 1 second, a plasma stored energy of about 11 MJ, and a QDT value of 1.05, using a relatively low plasma current of 2.8 MA and an external heating power of 17 MW. In Fig. 2-3 these new results of JT-60 are plotted along with the recent results of other tokamaks.

Reference Y. Koide et al., Progress in Confinement and Stability with Plasma Shape and Profile Control for Steady-State Operation in JT-60, Phys. Plasmas, 4(5), 1623 (1997).

Select a topic in left column