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# 27th IAEA Fusion Energy Conference - IAEA CN-258

22-27 October 2018
Mahatma Mandir Conference Centre
Asia/Kolkata timezone
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## Safety factor profile control with reduced CS flux consumption during plasma current ramp-up phase using reinforcement learning technique

24 Oct 2018, 08:30
4h
Mahatma Mandir Conference Centre

Poster

### Speaker

Dr Takuma Wakatsuki (National Institutes for Quantum and Radiological Science and Technology)

### Description

Safety factor profile control via active feedback control of electron temperature profile during a plasma current ramp-up phase of a DEMO reactor is investigated to minimize the magnetic flux consumption of a central solenoid (CS) for wide range of *q* profiles. It is shown that *q* profiles with positive, weak and reversed magnetic shear can be obtained with less than half of the empirical estimation of the resistive flux consumption ($\Psi_{\rm res}$). For the optimization of time dependent feedback gain, we introduced a reinforcement learning technique. This enables to follow a rapid change in the target profile of the electron temperature by changing the feedback gain adaptively. With this adaptive feature of the reinforcement learning, we also confirmed that $T_{\rm e}$ profile can be controlled in the plasma simulation with various thermal transport property by one control system.
Country or International Organization Japan EX/P3-25

### Primary author

Dr Takuma Wakatsuki (National Institutes for Quantum and Radiological Science and Technology)

### Co-authors

Dr Naoyuki Oyama (National Institutes for Quantum and Radiological Science and Technology) Dr Nobuhiko Hayashi (National Institutes for Quantum and Radiological Science and Technology) Dr Shunsuke Ide (National Institutes for Quantum and Radiological Science and Technology) Dr Takahiro Suzuki (National Institutes for Quantum and Radiological Science and Technology) Dr Yutaka Kamada (National Institutes for Quantum and Radiological Science and Technology)