Abstract Reliable mitigation is necessary to eliminate the detrimental effects of a disruption event in large high-current tokamaks such as ITER. To avoid serious damage to plasma-facing components during the thermal quench phase of a disruption, material is injected to radiate the plasma energy over the inner surface of the machine. The most promising method of material injection is a process known as shattered pellet injection (SPI). SPI utilizes cryogenic cooling to desublimate gas into the barrel of a pipe gun to form a solid pellet. High-pressure gas or a mechanical punch is used to dislodge the pellet and accelerate it into a bent tube to intentionally fracture it. Pellets made of a mixture of deuterium and neon are likely candidates for thermal mitigation. The survivability of these pellets throughout their flight path, before striking the shatter tube, is essential for reliable SPI operation. Experiments were conducted to determine intact speed limits for various mixtures. This paper outlines the details of brittle fracture theory and compares a theory-based model to experimental results from various mixtures of deuterium and neon pellets.

中文翻译：

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用于托卡马克热缓解的氘-氖混合物低温颗粒的破碎阈值和碎片尺寸分布

摘要 可靠的缓解措施对于消除大型高电流托卡马克（如 ITER）中断事件的不利影响是必要的。为了避免在中断的热淬火阶段对面向等离子体的组件造成严重损坏，注入材料以在机器的内表面上辐射等离子体能量。最有前途的材料注射方法是一种称为破碎颗粒注射 (SPI) 的工艺。SPI 利用低温冷却将气体凝华到管枪的枪管中以形成固体颗粒。使用高压气体或机械冲头将颗粒移出并加速进入弯曲的管以故意将其破碎。由氘和氖混合物制成的颗粒很可能是热缓解的候选者。这些弹丸在整个飞行路径中的生存能力，在撞击破碎管之前，对于可靠的 SPI 操作至关重要。进行实验以确定各种混合物的完整速度限制。本文概述了脆性断裂理论的详细信息，并将基于理论的模型与各种氘和氖弹丸混合物的实验结果进行了比较。