Yutthapong Pianroj and Thawatchai Onjun

pp. 77 - 91

Abstract

The investigation of bootstrap current formation in ITER is carried out using BALDUR integrated predictive modeling
code. The combination of Mixed B/gB anomalous transport model and NLCASS module together with the pedestal model is
used in BALDUR code to simulate the time evolution of temperature, density, and plasma current profiles. It was found in
the simulations that without the presence of ITB, a minimal fraction of bootstrap current (as well as low fusion performance)
was achieved. The enhancement due to ITB depends sensitively on the strength of toroidal velocity. A sensitivity study was
also carried out to optimize the bootstrap current fraction and plasma performance. It was found that the bootstrap current
fraction slightly improved; while the plasma performance greatly improved with increasing of NBI power or pedestal temperature. On the other hand, higher impurity concentration resulted in a significant degradation of fusion performance, but
a smaller degradation in bootstrap current.