基于多元线性回归模型的中性束质子比分析

Analysis of neutral beam proton ratio based on multiple linear regressive model

中性束质子比的高低对其注入等离子体后的加热效果具有重要的影响。实验中,强流离子源的灯丝电压、弧压、进气量等宏观运行参数决定了中性束质子比的大小。以东方超环中性束注入测试台束引出实验为基础,利用多元线性回归模型对引出中性束质子比进行分析,建立了影响中性束质子比的预测方程,并对该模型的正确性进行了检验。结果表明,中性束质子比可利用以灯丝电压和弧压为自变量的多元线性回归模型进行分析,灯丝电压是影响质子比的关键参数,弧压次之。

Background： Neutral beam injection （NBI） has been widely used in thermal nuclear fusion experiments for auxiliary heating. The high proton ratio can improve the efficiency of plasma heating and current drive, so it is essential to know the variations of the neutral beam proton ratio with discharge parameters. In the experiment, the macro operation parameters of high current ion source, such as filament voltage, arc voltage and gas flow rate, determine the level of neutral beam proton ratio. Purpose： This study aims to study the effect of the filament voltage and the arc voltage on the neutral beam proton ratio. Methods： Based on the beam extraction experiments applied on Experimental Advanced Superconducting Tokamak （EAST） NBI test bed, the multiple linear regressive model is used to analyze extraction neutral beam proton ratio. Results： The filament voltage and the arc voltage are positively correlated with the neutral beam proton ratio, and to establish the prediction equation which can give the value and the trends of the neutral beam proton ratio and the correctness of the model is proved. Conclusion： The neutral beam proton ratio can be analyzed by the multiple linear regressive model with the dependent variables of filament voltage and arc voltage. Between the two parameters, the filament voltage plays a major role in influencing proton ratio, and arc voltage is less important.