Application of Data Assimilation to Transport Simulations of Tokamak Plasmas

Data assimilation, a technique that uses actual measurements to optimize simulation models, is a powerful approach for achieving fast and accurate predictions of fusion plasma behavior. In this study, we validate the effectiveness of the data assimilation technique in the integrated simulation of tokamak plasmas. We use the data assimilation system ASTI, which has been successfully applied to real-time prediction and control of helical plasmas. We extend ASTI for transport simulation of tokamak plasmas and introduce a new data assimilation method that incorporates measurement error information. In this paper, we present simulation results using measurements from JT-60U plasma heated by neutral beam injection. Comparisons of several turbulent transport models are also provided. The results demonstrate that the data assimilation method is effective in tokamak simulation as well and expected to be useful for real-time prediction and control in the future.