TRANSP-based Optimization Towards Tokamak Scenario Development

Wehner, W. P.; Schuster, E.; Boyer, M. D.; Poli, F.

doi:10.11578/1562098

Title: TRANSP-based Optimization Towards Tokamak Scenario Development

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Other Related Research

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.

Authors:

Wehner, W. P.; Schuster, E.; Boyer, M. D.; Poli, F.

OSTI

Publication Date:: Mon Apr 01 00:00:00 EDT 2019

Research Org.:: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)

Sponsoring Org.:: U. S. Department of Energy

Subject:: DIII-D; NSTX-U; TRANSP; optimal control design; optimal plasma scenario planning; scenario development

OSTI Identifier:: 1562098

DOI:: https://doi.org/10.11578/1562098

Citation Formats


                    Wehner, W. P., Schuster, E., Boyer, M. D., and Poli, F. TRANSP-based Optimization Towards Tokamak Scenario Development.  United States: N. p., 2019. 
        Web.  doi:10.11578/1562098.

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

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                    Wehner, W. P., Schuster, E., Boyer, M. D., and Poli, F. 2019.  
"TRANSP-based Optimization Towards Tokamak Scenario Development".  United States.  doi:https://doi.org/10.11578/1562098.  https://www.osti.gov/servlets/purl/1562098. Pub date:Mon Apr 01 00:00:00 EDT 2019

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@article{osti_1562098,

  title        = {TRANSP-based Optimization Towards Tokamak Scenario Development},

  author       = {Wehner, W. P. and Schuster, E. and Boyer, M. D. and Poli, F.},

  abstractNote = {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.},

  doi          = {10.11578/1562098},

  journal      = {},

  number       = ,

  volume       = ,

  place        = {United States},

  year         = {Mon Apr 01 00:00:00 EDT 2019},

  month        = {Mon Apr 01 00:00:00 EDT 2019}

}

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DOI: https://doi.org/10.11578/1562098

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