Researchers from the National Institutes for Quantum Science and Technology in Japan, led by T. Wakatsuki, have made significant strides in the realm of nuclear fusion energy, focusing on the JT-60SA project. Their recent study, published in the journal Nuclear Fusion, explores a cutting-edge approach to plasma control that could enhance the feasibility of steady-state fusion reactors.
At the heart of their research is the internal transport barrier (ITB), a crucial feature that can improve plasma stability and confinement. Achieving and maintaining ITB plasma is essential for the efficiency of fusion reactions, but it comes with challenges, particularly the risk of magnetohydrodynamic instabilities. To navigate these complexities, the team has developed a sophisticated control system that simultaneously manages two key parameters: the safety factor profile (q) and the normalized beta (β_N).
The innovative control system employs a two-stage neural network (NN) framework. The first stage is responsible for estimating the strength of the ITB based on real-time measurements. The second stage consists of multiple NNs, each trained to manage the q profile and β_N for different ITB strengths. This tailored approach allows for precise adjustments based on the current state of the plasma. As Wakatsuki explains, “According to the ITB strength estimated by the NN in the first stage, the appropriate NN for control is selected from those in the second stage.”
This research has significant implications for the energy sector. Enhanced control over plasma behavior could lead to more stable and efficient fusion reactions, potentially paving the way for commercial fusion energy production. As fusion technology matures, it promises a cleaner and virtually limitless energy source, addressing global energy demands while reducing reliance on fossil fuels.
The study’s validation through simulations using integrated transport codes demonstrates the practicality of this control system. The ability to achieve stable control of the safety factor profile and normalized beta in ITB plasmas suggests that the methods developed could be applied to real-world fusion reactors in the near future.
In summary, Wakatsuki and his team’s work represents a promising advancement in the quest for sustainable fusion energy. As the world seeks innovative solutions to energy challenges, the findings published in Nuclear Fusion could play a pivotal role in shaping the future of energy production.
