Spoke射频超导腔的等离子后处理技术研究

In the fields of advanced nuclear energy technology and nuclear fuel cycle technology, high intensity proton linac is the focus of attention, while the Spoke RF superconducting cavity is the most important technology used for intense beam proton accelerator. Currently, difficulties appeared in post treatment process of the 600-800MHz Spoke cavity. Plasma processing technique is put forward to specifically deal with the problem. Through several aspects of research, the application of plasma post treatment on the Spoke cavity will be realized, and the overall effect of the post treatment will also be investigated. The research aspects conclude as: (1) Local plasma processing is combined to complete entire plasma treatment of the cavity, inspects the field emission, Q value and acceleration performance; (2) The interactions between plasma and niobium metal surface will be researched by experimental and theoretical studies, the laws of physics in plasma removing carbon, acid and hydrogen gas residue will be explored; (3) Plasma etching technology on the Nb surface will be researched to inhibit of field emission of surface, and modify the morphology of Nb surface. Since the technology of plasma processing has Characteristics of clean, simple, local control, low cost, safe and reliable, its application has a great advantage.

现今的先进核能和核燃料循环技术领域中,强流质子直线加速器是倍受关注的焦点,而Spoke射频超导加速腔则是用于强流质子加速器的核心技术。目前600 ～ 800MHz的Spoke腔在后处理技术方面遇到困难，本课题提出了用等离子体后处理技术专门解决Spoke腔的后处理问题。我将通过几方面的研究，实现该技术在Spoke腔上的应用，检测Spoke腔经过等离子后处理后的整体效果。（1）用局部等离子处理的组合完成整腔的等离子后处理，考察整腔的场致发射，Q值和加速性能的改善效果；（2）开展等离子体和铌金属表面相互作用的基础实验和理论研究，研究等离子体去除碳、酸液和氢气气体的残留的物理规律。（3）等离子体刻蚀技术对Nb表面的修饰功能，研究等离子体抑制Nb表面场致发射和改变Nb表面形貌的规律。由于等离子后处理技术具有洁净、简单、可进行局部控制、成本低廉、安全可靠等特点，在推广应用方面有很大的优势。