Simulation of START shots with the canonical profile transport model

The canonical profile transport model, which has been benchmarked previously for tokamaks with a conventional aspect ratio, is applied to simulations of the spherical tokamak START. A set of Ohmic shots is used to modify the model so that it is appropriate for the specific conditions of the spherical tokamak plasma. The application of the model as a tool to analyze neutral beam-heated START shots allows the estimation of the neutral beam-injection power absorbed by the plasma, P-NB(abs), which is experimentally uncertain. The modeling shows that both P-NB(abs) and the energy confinement time increase with increasing the average density. Finally, the modified model is used to simulate the performance of the new megaampere spherical tokamak MAST at Culham. (C) 2000 MAIK "Nauka/Interperiodica".