This concept was originally invented as a means of resolving the siting deadlock of ITER construction. It has since grown into the development of a broader approach to fusion development, it being recognised that not all the necessary information needed for the construction of a power reactor can be gathered by ITER alone, and that other complementary facilities would accelerate the development of magnetic fusion. These include:

• a remote experimental control centre as an alternate focus for interaction with ITER;
• a virtual plasma modelling laboratory, to bring together models for plasma behaviour on ITER and to make predictions, feeding back information subsequently from ITER operation;
• a “satellite” tokamak providing support (and the ability to rapidly evaluate new ideas) during ITER construction and operation;
• the DEMO design team;
• a DEMO materials test/qualification facility (IFMIF).

The most important element in the above list is the materials test facility, without which it will be difficult to qualify the structural materials needed to license DEMO. A change in these materials is necessary for the higher neutron fluences to be experienced in the devices following ITER. Although the materials will be tested in ITER operation in the test blanket modules, little information on their endurance will be available from ITER, due to its low accumulation rate for neutron damage.

The other facilities will allow ITER to do more, sooner, by providing the ability to conduct experiments for longer periods per day, and by increasing the speed of understanding and exploiting any new phenomena ITER reveals.

As a result of the agreement on the construction site for ITER, Japan and Europe have both agreed to make contributions of 49 B¥/339 M€ (May 2005 values) to projects from the above list (or other suitable projects) to be sited in Japan. These will be open also to the other future ITER Parties to co-fund and join in participation.