# A machine-learning-based tool for last closed-flux surface reconstruction on tokamaks

arXiv: https://arxiv.org/abs/2207.05695 · HTML: https://mlsanity.com/paper/2207.05695/

## Key facts

- Cited by 3 papers in the map (data through 14 Oct 2026).
- Builds on 6 of its 64 references that are in the map.
- First posted on arXiv 12 Jul 2022.

## Builds on (most cited first, 6 of 6)

- [Attention Is All You Need](https://mlsanity.com/paper/1706.03762/) (2017)
- [BERT: Pre-training of Deep Bidirectional Transformers for Language Understanding](https://mlsanity.com/paper/1810.04805/) (2018)
- [Swin Transformer: Hierarchical Vision Transformer using Shifted Windows](https://mlsanity.com/paper/2103.14030/) (2021)
- [Super-Convergence: Very Fast Training of Neural Networks Using Large Learning Rates](https://mlsanity.com/paper/1708.07120/) (2017)
- [Deep neural network Grad-Shafranov solver constrained with measured magnetic signals](https://mlsanity.com/paper/1911.02882/) (2019)
- [Experiment data-driven modeling of tokamak discharge in EAST](https://mlsanity.com/paper/2007.10552/) (2020)

## Built on by (most cited first, 3 of 3)

- [TokaMark: A Comprehensive Benchmark for MAST Tokamak Plasma Models](https://mlsanity.com/paper/2602.10132/) (2026)
- [XiHeFusion: Harnessing Large Language Models for Science Communication in Nuclear Fusion](https://mlsanity.com/paper/2502.05615/) (2025)
- [FusionMAE: large-scale pretrained model to optimize and simplify diagnostic and control of fusion plasma](https://mlsanity.com/paper/2509.12945/) (2025)

## Abstract (arXiv)

Nuclear fusion represents one of the best alternatives for a sustainable source of clean energy. Tokamaks allow to confine fusion plasma with magnetic fields and one of the main challenges in the control of the magnetic configuration is the prediction/reconstruction of the Last Closed-Flux Surface (LCFS). The evolution in time of the LCFS is determined by the interaction of the actuator coils and the internal tokamak plasma. This task requires real-time capable tools able to deal with high-dimensional data as well as with high resolution in time, where the interaction between a wide range of input actuator coils with internal plasma state responses add additional layer of complexity. In this work, we present the application of a novel state of the art machine learning model to the LCFS reconstruction in the Experimental Advanced Superconducting Tokamak (EAST) that learns automatically from the experimental data of EAST. This architecture allows not only offline simulation and testing of a particular control strategy, but can also be embedded in the real-time control system for online magnetic equilibrium reconstruction and prediction. In the real-time modeling test, our approach achieves very high accuracies, with over 99% average similarity in LCFS reconstruction of the entire discharge process.