Vacuum systems of neutral beam injectors have very demanding requirements in terms of pumping speed, throughput, and capacity. Due to their high affinity to hydrogenic species, porous sintered Non-Evaporable Getters (NEG) are a possible candidate for deployment in giant hydrogen ion sources and neutral beam injectors for fusion. This paper presents the numerical interpretation of experimental tests on a recently developed NEG cartridge, that is part of a modular pump under development for neutral beam injectors. The cartridge is composed of six stacks of ZAO® porous sintered NEG disks and a heater. It was tested under hydrogen loads relevant for neutral beam injectors, namely, at constant pressure or constant flow, such that the hydrogen pressure was in the range of 20 mPa-40 mPa. The result of the sorption test was reproduced by a three dimensional flow simulation in molecular regime to determine the actual pumping speed, the effective sticking coefficient, and the uniformity of the gas load on the various NEG disks. The procedure developed and the results obtained provide the basic understanding for interpreting the large-scale tests on the modular pump, consisting of 34 of these cartridges.

中文翻译：

---

在专为中性束喷射器应用设计的 ZAO® 非蒸发吸气泵上进行的实验测试的数值模拟

中性射束喷射器的真空系统在抽速、吞吐量和容量方面有非常苛刻的要求。由于它们对氢物质的高亲和力，多孔烧结非蒸发吸气剂 (NEG) 是部署在巨型氢离子源和中性束注入器中进行聚变的可能候选材料。本文介绍了最近开发的 NEG 墨盒的实验测试的数值解释，该墨盒是正在为中性束喷射器开发的模块化泵的一部分。滤芯由六叠 ZAO® 多孔烧结 NEG 盘和一个加热器组成。它在与中性射束喷射器相关的氢气负载下进行测试，即在恒压或恒流下，使得氢气压力在20 mPa-40 mPa的范围内。吸附测试的结果通过分子状态下的三维流动模拟再现，以确定实际抽速、有效粘附系数和各种 NEG 盘上气体负载的均匀性。开发的程序和获得的结果为解释模块化泵的大规模测试提供了基本的理解，模块化泵由 34 个这些墨盒组成。