TAE Technologies, Inc., 19631 Pauling, Foothill Ranch, California 92610, USA.
Rev Sci Instrum. 2021 May 1;92(5):053502. doi: 10.1063/5.0043820.
In TAE Technologies' current experimental fusion device, C-2W (also called "Norman"), record breaking, advanced beam-driven field-reversed configuration plasmas are produced and sustained in steady state utilizing variable-energy neutral beams, expander divertors, end-bias electrodes, and an active plasma control system. With a rapid shot-pace and an extensive number of data channels, the amount of data generated necessitates automated signal processing. To this end, a machine learning algorithm consisting of a multi-layered neural network as well as other data processing software has been designed for signal feature identification, allowing for accurate and fast signal classification, anomalous condition detection, and providing for signal pre-processing. With a small set of training data, the neural network can be "bootstrapped" to provide a robust classification system while minimizing human oversight. An example using data from the theta pinch plasma formation pulsed power system is presented. With an overall accuracy of ∼97%-having classified more than 5 × 10 pulsed power signals-the classification scheme is more than sufficient to fine-tune machine set points. However, this technique can be used for near-real-time preprocessing of any plasma physics signal and has wide ranging application in fusion experiments for the varied data produced by plasma diagnostics.
在 TAE 技术公司目前的实验性聚变设备 C-2W(也称为“诺曼”)中,利用可变能量中性束、扩展器偏滤器、末端偏置电极和主动等离子体控制系统,产生并稳定维持创纪录的先进束驱动场反转配置等离子体。由于快速的射击速度和大量的数据通道,生成的数据量需要自动化信号处理。为此,设计了一种由多层神经网络以及其他数据处理软件组成的机器学习算法,用于信号特征识别,从而实现准确快速的信号分类、异常情况检测,并提供信号预处理。通过使用一小部分训练数据,神经网络可以“自举”,从而提供一个强大的分类系统,同时最大限度地减少人工监督。使用来自 theta pinch 等离子体形成脉冲功率系统的数据示例进行了说明。该分类方案的总体准确性约为 97%,已经对超过 5×10 个脉冲功率信号进行了分类,足以微调机器的设定点。然而,该技术可用于任何等离子体物理信号的近实时预处理,并且在聚变实验中具有广泛的应用,可用于处理等离子体诊断产生的各种数据。