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DOE OSTI · 1562098

TRANSP-based Optimization Towards Tokamak Scenario Development

Wehner, W. P.·Schuster, E.·Boyer, M. D.·Poli, F.
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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 bya flat loop voltage profile in the flattop phase.

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DIII-DNSTX-Uoptimal control designoptimal plasma scenario planningscenario developmentTRANSP

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Wehner, W. P., Schuster, E., Boyer, M. D., Poli, F.. 2019-04-01. TRANSP-based Optimization Towards Tokamak Scenario Development. https://doi.org/10.11578/1562098

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