二次电子发射现象由于在现代分析仪器及微波器件中的重要影响,一直以来是物理电子领域研究的基础和重点。表面形貌是影响材料二次电子发射特性的关键参量,但目前对于金属二次电子产额(secondary electron yield,SEY)与表面形貌之间的定...二次电子发射现象由于在现代分析仪器及微波器件中的重要影响,一直以来是物理电子领域研究的基础和重点。表面形貌是影响材料二次电子发射特性的关键参量,但目前对于金属二次电子产额(secondary electron yield,SEY)与表面形貌之间的定量关系研究尚十分欠缺。矩形槽结构由于具有显著降低二次电子产额的特性,是加速器、高功率微波源等广泛应用的抑制结构,文章分析了表面结构特征对二次电子出射的遮挡作用和再入射过程,从理论上推导了电子正入射矩形槽结构时的二次电子产额。通过Monte Carlo模拟和实验结果的对比,所获得的解析模型均能很好的与仿真结果和实验结果相吻合。展开更多
For modern and future circular accelerators, especially high-intensity proton synchrotrons or colliders, the electron cloud effect is a key issue. So, in order to reduce the electron cloud effect, exploring very low s...For modern and future circular accelerators, especially high-intensity proton synchrotrons or colliders, the electron cloud effect is a key issue. So, in order to reduce the electron cloud effect, exploring very low secondary electron yield （SEY） material or coating used in vacuum tubes becomes necessary. In this article, we studied the SEY characteristics of graphene films with different thicknesses which were deposited on copper substrates using chemical vapor deposition. The SEY tests were done at temperatures of 25 ℃and vacuum pressure of （2-6）x 10-9 torr. The properties of the deposited graphene films were investigated by X-ray photoelectron spectroscopy （XPS） and Raman spectroscopy. The SEY curves show that the number of graphene layers has a great effect on the SEY of graphene films. The maximum SEY of graphene films decreases with the increase of the number of layers. The maximum SEY of 6-8 layers of graphene film is 1.25. These results have a great significance for next-generation particle accelerators.展开更多
文摘二次电子发射现象由于在现代分析仪器及微波器件中的重要影响,一直以来是物理电子领域研究的基础和重点。表面形貌是影响材料二次电子发射特性的关键参量,但目前对于金属二次电子产额(secondary electron yield,SEY)与表面形貌之间的定量关系研究尚十分欠缺。矩形槽结构由于具有显著降低二次电子产额的特性,是加速器、高功率微波源等广泛应用的抑制结构,文章分析了表面结构特征对二次电子出射的遮挡作用和再入射过程,从理论上推导了电子正入射矩形槽结构时的二次电子产额。通过Monte Carlo模拟和实验结果的对比,所获得的解析模型均能很好的与仿真结果和实验结果相吻合。
基金Supported by the National Natural Science Foundation of China(11475166)National Natural Science Foundation of China(11205155)National Natural Science Foundation of China(11575214)
文摘For modern and future circular accelerators, especially high-intensity proton synchrotrons or colliders, the electron cloud effect is a key issue. So, in order to reduce the electron cloud effect, exploring very low secondary electron yield （SEY） material or coating used in vacuum tubes becomes necessary. In this article, we studied the SEY characteristics of graphene films with different thicknesses which were deposited on copper substrates using chemical vapor deposition. The SEY tests were done at temperatures of 25 ℃and vacuum pressure of （2-6）x 10-9 torr. The properties of the deposited graphene films were investigated by X-ray photoelectron spectroscopy （XPS） and Raman spectroscopy. The SEY curves show that the number of graphene layers has a great effect on the SEY of graphene films. The maximum SEY of graphene films decreases with the increase of the number of layers. The maximum SEY of 6-8 layers of graphene film is 1.25. These results have a great significance for next-generation particle accelerators.
