A new paradigm for real-time plasma profile reconstruction is demonstrated in the TCV tokamak. Predictions based on physics models are merged with available real-time diagnostic data to construct a self-consistent profile state estimate compatible with a timedependent model of transport processes in the plasma. This is enabled by a new RApid Plasma Transport simulatOR (RAPTOR), implemented in the new TCV real-time control system. RAPTOR simulates the radial current diffusion including the ohmic coil transformer voltage and non-inductive sources in real-time, while the plasma physically evolves in the tokamak. This makes available an extensive set of quantities which are normally not known in real-time such as the bootstrap current fraction, safety factor, magnetic shear and loop voltage profiles. This approach represents a generalization of existing approaches for real-time equilibrium reconstruction with measurement-constrained current density profile, as transport physics knowledge is now included in the reconstruction. The same rapid transport code is also used in predictive mode, including a model of the electron temperature evolution, for off-line studies of optimal actuator trajectories during plasma ramp-up scenarios. Constraints are included in the optimization to reflect realistic operational limits. These studies show that a plasma current overshoot combined with appropriately timed heating are beneficial for rapidly reaching a stationary q profile with flat central shear. The demonstration of this new paradigm paves the way for further integration of real-time tokamak plasma simulations for prediction, scenario monitoring, disruption avoidance and feedback control.
[1]
K. Miyamoto,et al.
Plasma physics and controlled nuclear fusion
,
1979
.
[2]
D K Smith,et al.
Numerical Optimization
,
2001,
J. Oper. Res. Soc..
[3]
L. C. Woods.
Physics of plasmas
,
2003
.
[4]
Carlos Varandas.
17th IEEE NPSS Real Time Conference – RT-2010
,
2010
.
[5]
T.K. Fowler,et al.
Nuclear fusion
,
1989,
IEEE Potentials.
[6]
W. Dorland,et al.
Plasma Physics and Controlled Fusion
,
1984
.
[7]
S. WEINTROUB,et al.
A Review of Scientific Instruments
,
1932,
Nature.