TRANSP-based Optimization Towards Tokamak Scenario Development

Wehner, W. P.; Schuster, E.; Boyer, M. D. ; Poli, F.
Issue date: 2019
Rights:
Creative Commons Attribution 4.0 International (CC BY)
Cite as:
Wehner, W. P., Schuster, E., Boyer, M. D., & Poli, F. (2019). TRANSP-based Optimization Towards Tokamak Scenario Development [Data set]. Version 1. Princeton Plasma Physics Laboratory, Princeton University. https://doi.org/10.11578/1562098
@electronic{wehner_w_p_2019,
  author      = {Wehner, W. P. and
                Schuster, E. and
                Boyer, M. D. and
                Poli, F.},
  title       = {{TRANSP-based Optimization Towards Tokama
                k Scenario Development}},
  version     = 1,
  publisher   = {{Princeton Plasma Physics Laboratory, Pri
                nceton University}},
  year        = 2019,
  url         = {https://doi.org/10.11578/1562098}
}
Description:

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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