中性束注入(NBI)加速器短路故障时, 根据B-H曲线和高压缓冲器的结构尺寸, 在Fink的Snubber分析方法基础上, 分别导出高压缓冲器任意铁芯叠片层的感应电压、涡流电阻与铁芯叠片层饱和深度的关系；利用安培环路定律, 推出不同铁芯叠片层中涡流大小、饱和深度表达式, 从而导出整个高压缓冲器随铁芯饱和深度变化的等效涡流电阻的表达式。根据Snubber的等效涡流电阻及NBI系统的杂散电容, 分析故障时的瞬态短路电流回路, 得到了铁芯叠片饱和深度的指数时间常数与电弧电流的表达式；得出高压缓冲器铁芯叠片的最大宽度及最小厚度分别为28 mm和114 μm。经实验测试和理论计算对比分析可知, 铁芯叠片饱和深度的指数时间常数的测试值与理论值基本吻合。

According to the B-H curve and structure dimensions of the Snubber, induction voltage and eddy current of any core lamination with the thickness of saturated regions are derived by referring to Fink’s method, when accelerator breakdown occurs at the Experimental Advanced Superconducting Tokamak(EAST). Using Ampere’s law, in each core tape, the eddy current and the thickness of saturated regions are deduced. And then, the equivalent resistance of the Snubber is obtained. The transient eddy current due to stray capacitance is analyzed, and the exponential time constant and the arc current are obtained. Then the maximum width of the lamination and the minimum thickness of the core tape are 28 mm and 114 μm, respectively. The obtained experimental time constant is approximately the same as the calculated one, which proves the accuracy and efficiency of the analysis method.