A fluid model without an external circuit is used in simulating self-pulses in hollow cathode discharge under a He-Ar gas at 10 Torr. The average discharge current increases with anode potential, and three types of self-pulsing discharge modes are obtained: (a) regular self-pulse, (b) low amplitude self-pulse, and (c) damped oscillating pulses modes. The temporal and spatial distributions of plasma parameters in the self-pulsing discharge mode are studied. Results show that the electron density, electric potential, electric field, total net electron production rates integrated over the entire discharge cell and net positive charge density change periodically in a self-pulsing period. Self-pulsing frequency ranges from tens of kHz to more than 100 kHz, and increases linearly with the average discharge current approximately. In the present average discharge current range, the peak value and current amplitude of pulsing current increases and then decreases with the increasing average current, whereas the minimum pulsing current consistently increases. The change trend of extreme self-pulsing discharge current is consistent with the change trends of total net electron production rate and net positive charge density in the discharge space. Finally, the mechanism of self-pulse in a hollow cathode discharge is proposed. Simulated results show that the phases of different plasma parameters are different in different discharge regions in a self-pulsing period. Non-equilibrium fluctuation of plasma parameters in different discharge regions is one of important factors in the formation of self-pulse. Self-pulse does not depend on an external circuit and originates from the internal microcosmic mechanism of discharge: the enhancement and weakening of the positive charge layer.

没有外部电路的流体模型用于模拟在 10 Torr 的 He-Ar 气体下空心阴极放电的自脉冲。平均放电电流随着阳极电位的增加而增加，得到三种类型的自脉冲放电模式：（a）规则自脉冲，（b）低幅自脉冲，和（c）阻尼振荡脉冲模式。研究了自脉冲放电模式下等离子体参数的时空分布。结果表明，电子密度、电势、电场、在整个放电单元上积分的总净电子产生率和净正电荷密度在自脉冲周期内周期性变化。自脉冲频率范围从几十 kHz 到超过 100 kHz，并且大约随平均放电电流线性增加。在目前的平均放电电流范围内，脉冲电流的峰值和电流幅值随着平均电流的增大而先增大后减小，而最小脉冲电流则一直增大。极端自脉冲放电电流的变化趋势与放电空间中总净电子产率和净正电荷密度的变化趋势一致。最后，提出了空心阴极放电中的自脉冲机制。仿真结果表明，自脉冲周期内不同放电区域不同等离子体参数的相位不同。不同放电区域等离子体参数的非平衡波动是自脉冲形成的重要因素之一。