TRANSP-based Optimization Towards Tokamak Scenario Development

W.P. Wehner, E. Schuster, M.D. Boyer, F. Poli
Issue date: April 2019
Cite as:
W.P. Wehner, E. Schuster, M.D. Boyer, F. Poli. (2019). TRANSP-based Optimization Towards Tokamak Scenario Development [Data set]. Princeton Plasma Physics Laboratory, Princeton University.
@electronic{wp_wehner_e_schuster_md_boyer_f_poli_2019,
  author      = {W.P. Wehner, E. Schuster, M.D. Boyer, F. Poli},
  title       = {{TRANSP-based Optimization Towards Tokama
                k Scenario Development}},
  publisher   = {{Princeton Plasma Physics Laboratory, Pri
                nceton University}},
  year        = 2019
}
Abstract:

An optimization approach that incorporates the predictive transport code TRANSP is proposed for tokamak scenario development. Optimization methods are often employed to develop open-loop control strategies to aid access to high performance tokamak scenarios. In general, the optimization approaches use control-oriented models, i.e. models that are reduced in complexity and prediction accuracy as compared to physics-oriented transport codes such as TRANSP. In the presented approach, an optimization procedure using the TRANSP code to simulate the tokamak plasma is considered for improved predictive capabilities. As a test case, the neutral beam injection (NBI) power is optimized to develop a control strategy that maximizes the non-inductive current fraction during the ramp-up phase for NSTX-U. Simulation studies towards the achievement of non-inductive ramp up in NSTX-U have already been carried out with the TRANSP code. The optimization-based approach proposed in this work is used to maximize the non-inductive current fraction during ramp-up in NSTX-U, demonstrating that the scenario development task can be automated. An additional test case considers optimization of the current ramp rate in DIII-D for obtaining a stationary plasma characterized by a flat loop voltage profile in the flattop phase.

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