Co-deposition of carbon atoms with hydrogen isotopes and hydrogenated carbon radicals and molecules is recognized as the main mechanism for tritium retention in the graphite walls of the previous tokamak fusion devices. Significant tritium retention would be a serious concern for safe and economic long-term operation of future fusion test reactors and fusion energy systems. Similar deposits are observed on the surface of the engineered components in a tritium-producing assembly, known as a Tritium-Producing Burnable Absorber Rod (TPBAR). Characterization of the deposits can help understand the tritium transport, accumulation history and distribution in TPBARs. This study reports our recent results from the carbonaceous deposits formed on an aluminide-coated cladding in the lower plenum of a TPBAR following thermal neutron irradiation. The observed deposits are amorphous in nature, consisting of flakes of interconnected nanoscale features. They contain primarily double-bonded carbon (e.g., alkene) and carbonyl carbon, as well as a minor fraction of aliphatic carbon, all of which are likely tritiated. A similar co-deposition process that occurred in previous fusion devices is responsible for the formation and growth of the carbonaceous deposits.

碳原子与氢同位素以及氢化的碳自由基和分子的共沉积被认为是tri保留在以前的托卡马克聚变装置的石墨壁中的主要机理。对于未来的聚变测试反应堆和聚变能源系统的安全和经济的长期运行，tri的显着保留将是一个严重的问题。在生产tri的组件（称为a生产的可燃吸收棒（TPBAR））中，在工程组件的表面上观察到了类似的沉积物。沉积物的表征可以帮助了解T的迁移，积累历史和TPBAR中的分布。这项研究报告了我们最近的结果，这些结果来自热中子辐照后在TPBAR下部集气室中铝化物涂层覆盖层上形成的碳质沉积物。观察到的沉积物本质上是无定形的，由相互连接的纳米级特征的薄片组成。它们主要包含双键碳（例如烯烃）和羰基碳，以及少量脂族碳，所有这些都可能被tri化了。在以前的熔融装置中发生的类似的共沉积过程是碳质沉积物形成和生长的原因。