EFDA-JET-PR(04)61

Fully Predictive Simulations of Current and Temperature Profile Control in JET Advanced Tokamak Plasmas and Comparison with Experiments

For the first time fully predictive, time-dependent transport simulations with a non-linear plasma model (Bohm/GyroBohm transport model) have been used in closed-loop simulations to control the q-profile and the strength and location of the ITB. Five transport equations (Te, Ti, q, ne,vΦ) are solved, and the power levels of LHCD, NBI and ICRH are calculated in a feedback loop determined by the feedback controller matrix. The real-time control technique and algorithms used in the transport simulations are identical to those implemented and used in JET experiments. The closed-loop simulations with real-time control demonstrate that varieties of q-profiles and pressure profiles in the ITB can be achieved and controlled simultaneously. The simulations also showed that with the same real-time control technique as used in JET experiments, it is possible to sustain the q-profiles and pressure profiles close to their set-point profiles for longer than the current diffusion time. The importance of being able to handle the multiple time scales to control the location and strength of the ITB is demonstrated. Several future improvements and perspectives of the real-time control scheme are presented.
Name Size  
EFDP04061 1.50 Mb