We use Letokhov’s concept of stochastic feedback to interpret experiments on X-ray spontaneous emission from a polydisperse plasma of a nanosecond vacuum discharge (NVD) with a virtual cathode. We develop a diffusion model of stochastic propagation of spontaneous X-ray radiation in the volume of randomly located reflecting clusters. The model provides qualitative explanation of both the experimentally observed effects of partial “trapping” and high-intensity bursts of X-ray quanta. The X-ray burst regime is a result of the photon density accumulation which, due to diffusion inside the inter-electrode volume, exceeds the losses from the surface, while the trapping regime corresponds to the slow developing diffusion, which characteristic time is larger than the discharge duration.

我们使用Letokhov的随机反馈概念来解释从具有虚拟阴极的纳秒级真空放电（NVD）的多分散等离子体的X射线自发发射的实验。我们建立了随机分布的反射簇中自发X射线辐射随机传播的扩散模型。该模型对实验观察到的部分“陷获”和X射线量子的高强度猝发效应提供了定性解释。X射线猝发机制是光子密度累积的结果，由于电极间体积内部的扩散，光子密度累积超过了来自表面的损耗，而捕获机制对应于缓慢发展的扩散，其特征时间大于放电持续时间。