In particle-in-cell simulations, excessive or even unfeasible computational demands can be caused by the growth of particle number in the course of prolific ionization or cascaded pair production due to the effects of quantum electrodynamics. Here we discuss how one can arrange a dynamic shrinking of the macro-particle ensemble to maintain an acceptable sampling of arbitrary particle distribution. The approaches of merging and thinning as well as their variants are discussed and the aspects of their use are considered.

中文翻译：

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PIC 模拟中粒子重采样的策略

在细胞内粒子模拟中，由于量子电动力学的影响，在大量电离或级联对产生过程中，粒子数量的增长可能导致过多甚至不可行的计算需求。在这里，我们讨论如何安排宏观粒子系综的动态收缩，以保持任意粒子分布的可接受采样。讨论了合并和细化的方法及其变体，并考虑了它们的使用方面。