ITER: opportunity of burning plasma studies

ITER is planned to be the first fusion experiment operating under reactor-relevant conditions. The following requirements are given: ITER should (1) achieve extended burn in inductively driven plasma at Q ⩾ 10, whilst not precluding the possibility of controlled ignition, (2) aim at demonstrating steady-state operation using non-inductive current drive at Q ⩾ 5, (3) demonstrate availability and integration of essential fusion technologies, and (4) test components for a future reactor including tritium breeding module concepts, with the 14 MeV neutron power load on the first wall ⩾ 0.5 MW m -2 and fluence ⩾ 0.3 MW am -2 . The ITER tokamak is designed not only to satisfy these requirements but also to have flexibility of plasma operations. This flexibility will provide a wide range of opportunities to develop inductive and non-inductive reactor core plasmas and to study burning plasma physics. Possible operational modes studying physics and technical issues of burning plasmas are overviewed.