加速器真空室内壁新型导电吸气剂薄膜的制备及性能研究

MBA (Multiple Bend Achromat) compact lattice of the diffraction-limited storage ring, which is combined with small magnet apertures, reduces the apertures of vacuum chambers to a few millimeters. Due to the limitation of vacuum conductance and collective instabilities associated with the impedance of small-aperture vacuum chambers, the research on vacuum performance and impedance of vacuum thin film getters become much important. In this study, the widely studied TiZrV non-evaporable getters will be alloyed with a conductive element X (Cu, Al, Ag) to enhance its conductivities while, at the same time, maintaining good vacuum pumping properties. However, such topic has been rarely studied. In this regards, TiZrV-X（Cu, Al, Ag）with various microstructure characteristics and chemical compositions will be produced by DC magnetron sputtering deposition through altering deposition parameters. The corresponding relationships between microstructure characteristics, chemical compositions, vacuum performance and vacuum impedances will be established. The expected outcomes of this project are to produce new conductive thin film getters with good vacuum performance and low impedance. This research will provide the strong technical base for achieving ultra-high vacuum of the future particle accelerators.

衍射极限储存环的MBA紧凑型磁聚焦结构，使真空室的尺寸降低到几个毫米。由于小孔径真空室流导的限制及其真空阻抗造成的束流不稳定性，使得对真空吸气剂薄膜的真空性能及真空阻抗的研究变得尤为重要。TiZrV-X（Cu，Al，Ag）薄膜作为一种新型非蒸散吸气剂薄膜，在传统的TiZrV薄膜中添加导电性好的元素X，保证其良好吸气性的同时兼具较低的阻抗，但目前国内外相关的研究资料还十分有限。本课题以TiZrV-X（Cu，Al，Ag）薄膜为研究对象，通过调控磁控溅射参数，制备具有不同微观组织特征及化学成分比例的TiZrV-X（Cu，Al，Ag）薄膜，通过对薄膜吸气性能、真空阻抗以及微观组织的对比分析，揭示直流磁控溅射工艺参数和薄膜成分对其真空吸气性能以及真空阻抗的影响。项目拟制备出具有良好真空性能和较低真空阻抗的新型导电吸气剂薄膜，研究成果可作为未来粒子加速器超高真空的技术基础。

具有极低发射度、高亮度的衍射极限储存环,其紧致型的多弯铁消色散结构设计，减小了真空室孔径的尺寸。由于小孔径真空室流导的限制和束流耦合阻抗的增加，增加真空室内部的压强梯度，恶化束流集体效应。因此，对真空吸气剂薄膜的真空性能及电性能的研究变得尤为重要。本项目以三元Ti-Zr-V和四元Ti-Zr-V-X（Cu，Al，Ag）薄膜作为研究对象，通过调控磁控溅射参数，制备具有不同微观组织特征及化学成分比例的三元Ti-Zr-V和四元Ti-Zr-V-X（Cu，Al，Ag）薄膜；通过对薄膜吸气性能、电性能以及微观组织的对比分析，揭示直流磁控溅射工艺参数-薄膜微观组织及成分-真空吸气性能以及电性能的内禀关系。研究结果表明，在传统的Ti-Zr-V薄膜中添加导电性好的元素X，虽然牺牲了薄膜部分的激活性能，但优化了薄膜的电性能。其中加入Ag的Ti-Zr-V四元导电吸气剂薄膜相较其他两类薄膜，展现了良好的激活性能，同时其电性能有了明显提升。本项目研究成果为未来粒子加速器超高真空系统的设计提供了理论依据和技术基础。