The Compact Ignition Tokamak Project

A review is presented of the Compact Ignition Tokamak (CIT) design. This design calls for a liquid-nitrogen-cooled, copper-coil ignition tokamak to utilize the TFTR facilities. The 1.75-m major radius machine will have a baseline magnetic field of 10.0 T and a double- diverted plasma current of 9 MA. The flattop magnetic-field pulse will be 5 s in duration. The peak temperature in the coils reaches about 300 K. The requirement for 3000 full-field, full-ignition pulses results in an integrated neutron dose near the limits for the unshielded organic insulators. The baseline toroidal field (TF) design uses pure wedging to support the TF inward loads, and locates the bulk of the poloidal field (PF) coils external to the TF coil. Internal PF coils are provided for control. Potential disruption of the large plasma current results in severe mechanical and thermal loading of the vacuum vessel. In-vessel divertors and wall protection are designed for efficient replacement by in-vessel remote maintenance equipment. The baseline machine will have the capacity to allow a 20% increase in magnetic field (with the option of additional power and mechanical preload) to provide margin, and a larger operating window, should it prove necessary.