ITER: A Magnetically Confined Burning Plasma

Previous deuterium-tritium plasma research produced 10 MW fusion power on the TFTR facility and 16 MW on the JET facility for durations ~1s.  In these pioneering experiments, the ratio of fusion power to external heating power was 0.27 and 0.64 in TFTR and JET respectively.  ITER is projected to generate 500 MW fusion power for 300 s with 50 MW external heating power increasing the ratio of fusion power to external heating power to 10. The achievement of burning plasmas, in which the self heating from alpha particles is greater than from external heating, will be the result of substantial developments in both the science of plasmas and the key technologies for magnetic fusion ranging from fabrication of large superconducting coils to construction of the vacuum vessel to design of heating and current drive systems.   The status of the design and construction of the facility will be presented. Successful operation of ITER will establish key technologies for magnetic fusion power plants.

The ITER facility while a major extension of the scientific and technical accomplishments of the worldwide fusion program is based on an extensive set of research and technical data.  Recent experimental results, which affect the design, will be reviewed.  ITER will address key scientific issues critical to magnetic fusion development.  The confinement and stability of plasmas capable of achieving large values of fusion power and hence alpha heating will be the first goal.  The subsequent achievement of high values of fusion power relative to the heating power will enable the study of the physics of burning plasmas in regimes, which were not accessible previously in JET and TFTR. Not only will the self-heating of the plasma be studied in regimes where the self-heating is dominant but also the effect of large populations of energetic alpha particles on plasma stability will be assessed. The understanding of the physics of burning plasma will also be applicable to other toroidal configurations. ITER will resolve key questions regarding the ability to achieve and control burning plasmas.