Plasma startup of the ARIES-III second stability advanced fuel tokamak

The ARIES-III conceptual reactor design utilizes D-³He fuel in a second stability tokamak configuration. The process of starting up the plasma and bringing it to the desired operating point was analyzed using a time-dependent particle and power balance code in conjunction with MHD (magnetohydrodynamic) equilibrium and stability, and neutral beam current drive calculations. Two different startup scenarios, one using D-T to assist reaching the D-³He operating point and one using only pure D-³He, were analyzed. In order to minimize the amount of ICRF (ion cyclotron range of frequencies) auxiliary heating required, one must program the plasma current so that the plasma enters second stability as soon as practical; it was assumed that confinement improves greatly when the plasma is in second stability. Seeding the plasma with tritium during startup reduces the amount of ICRF power required, but leads to a 14-MeV neutron pulse. The blanket and magnet heating due to this neutron pulse are within acceptable limits. The DT assisted startup was chosen as the reference procedure. Pure D-³He startup of ARIES-III can be achieved with 200 MW of heating power in addition to that available from the current drive system