JET's capabilities in support of ITER

The capabilities of JET can advance experience and understanding in many areas essential to ITER:

• due to its unique tritium handling capability, JET can actually study plasmas with a high rate of Deuterium-Tritium (D-T) fusion reactions (commonly known as "burning plasmas")

• due to the size of JET, it is the best suited facility to study the confinement of the fusion products, the fast alpha particles. The fast alpha particles have to be sufficiently confined in order to transfer their kinetic energy to other plasma particles (and thus maintain extreme plasma temperatures), but if they're too confined, they hamper the fusion process by dissolving the D-T fuel and increasing plasma radiation losses. At JET, we can produce fast alphas either in D-T fusion, or by their acceleration in plasmas on special radiofrequency waves.

• JET provides key contributions to the material studies and plasma-wall interaction studies due to JET's unique beryllium handling capability (beryllium being the design choice for the ITER first wall, i.e. the plasma facing material)

• JET extends experience of in-vessel remote handling techniques, based on its comprehensive Remote Handling facility (see Fig. 1 & 2).

Ongoing experimental studies on JET provide detailed groundwork for ITER operations. These include further optimisation of the "basic" operating scenario and development of "advanced" scenarios with a potential for increased fusion performance and steady state operation. An important part of this work is devoted to the development of extensive real-time control and powerful heating systems, and to the development of new plasma diagnostics and heating schemes. JET plays a dominant role in the international tokamak database that is used for extrapolations to ITER (see scaling laws), with data closest to the ITER working point. In addition, the JET experimental programme allows continuous benchmarking in order to develop an integrated set of modelling tools for the preparation and analysis of ITER experiments.

In 2004/2005 JET underwent numerous enhancements; notably a new JET divertor configuration has been set up, able to accommodate plasmas of an ITER-like shape at high currents (3.5-4 MA), and new neutron and alpha diagnostics tools as well as numerous devices for studies of plasma-wall interactions have been installed. A new high-power ITER-like Ion Cyclotron Resonant Heating antenna is under construction.

As a part of the "JET programme in support of ITER" proposed for 2005-2010, three major projects for upgrading JET were recently approved and launched. They are the "ITER-like wall", the "Neutral Beam Enhancement" and the "High Frequency Pellet Injector". Design work has started and calls for tenders are being made, with installation foreseen in 2008.