Two-dimensional electromagnetic (EM) particle-in-cell (PIC) simulations of a radial magnetically-insulated-transmission-line are presented and compared to the model of E. M. Waisman, M. P. Desjarlais, and M. E. Cuneo [Phys. Rev. Accel. Beams 22, 030402 (2019) in the “high-enhancement” (WDC-HE) limit. The simulations use quasi-equilibrium current and voltage values based on the Sandia National Laboratories $Z$ accelerator, with prescribed injection of an electron sheath that gives electron density profiles qualitatively similar to those used in the WDC-HE model. We find that the WDC-HE model accurately predicts the quasiequilibrium ion current losses in the EM PIC simulations for a wide range of current and voltage values. For the case of two ion species where one is magnetically insulated by the ambient magnetic field and the other is not, the charge of the lighter insulated species in the anode-cathode gap can modify the electric field profile, reducing the ion current density enhancement for the heavier ion species. On the other hand, for multiple ion species, when the lighter ions are not magnetically insulated and are a significant fraction of the anode plasma, they dominate the current loss, producing loss currents which are a significant fraction of the lighter ion WDC values. The observation of this effect in the present work is new to the field and may significantly impact the analysis of ion current losses in the $Z$ machine inner MITL and convolute.

中文翻译：

---

加速器内部磁绝缘传输线中增加的离子电流损耗的数值模拟

提出了径向电磁绝缘传输线的二维电磁（EM）单元内粒子（PIC）模拟，并将其与EM Waisman，MP Desjarlais和ME Cuneo [ Phys。牧师 梁 22，030402（2019）中的“高的增强”（WDC-HE）的限制。该仿真基于桑迪亚国家实验室的准平衡电流和电压值$ž$加速器，按规定注入电子鞘，其电子密度曲线在质量上与WDC-HE模型中所用的相似。我们发现，WDC-HE模型可以在EM PIC仿真中针对广泛的电流和电压值准确预测准平衡离子电流损耗。对于两种离子物质，其中一种通过环境磁场进行磁绝缘，而另一种则不能的情况，阳极-阴极间隙中较轻的绝缘物质的电荷会改变电场分布，从而降低离子电流密度较重的离子种类。另一方面，对于多种离子，当较轻的离子没有磁绝缘并且占阳极等离子体的很大一部分时，它们将占电流损耗的主要部分，产生的损耗电流是较轻离子WDC值的很大一部分。在当前工作中观察到这种效应对本领域来说是新的，并且可能会显着影响离子阱中离子电流损耗的分析。$ž$ 机器内部的MITL和回旋。