Abstract Breakdown voltages of helium between needle-plane copper electrodes were measured to obtain the base data for insulation design of the electrical equipment working in high temperature and pressure helium gas in the High Temperature Gas-cooled Reactor (HTGR). The measurements were performed at a gap length between 1.02 mm and 5.30 mm, temperature and pressure varying from 0.01 to 7 MPa and 25–180 °C, respectively. Some abnormal “U-shapes” were found to appear especially at pressure over 3 MPa, which can be explained by the effects of space charge on the corona layer. COMSOL Multiphysics was used to simulate the discharge with a two-dimensional drift–diffusion model. The results agree well with the experimental data on the whole, but the errors rise when the pressure and gap length become very large. Evolutions of the current and particle number densities were also obtained. These breakdown voltages and characteristics of helium discharge is considered much valuable to the insulation design in HTGR.

中文翻译：

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非均匀电场高压高温氦击穿实验与模拟

摘要 测量针平面铜电极间氦气的击穿电压，为高温气冷堆（HTGR）中在高温高压氦气中工作的电气设备的绝缘设计提供基础数据。测量是在 1.02 毫米和 5.30 毫米之间的间隙长度、温度和压力分别从 0.01 到 7 兆帕和 25-180 °C 变化的情况下进行的。一些异常的“U 形”被发现特别是在超过 3 MPa 的压力下出现，这可以通过空间电荷对电晕层的影响来解释。COMSOL Multiphysics 用于通过二维漂移-扩散模型来模拟放电。结果总体上与实验数据吻合较好，但当压力和间隙长度变大时，误差增大。还获得了电流和粒子数密度的演变。氦气放电的这些击穿电压和特性被认为对 HTGR 中的绝缘设计非常有价值。