{"title":"一个紧凑,低场,宽带匹配部分,用于外部供电的x波段介电负载加速结构","authors":"Yelong Wei, A. Grudiev, B. Freemire, C. Jing","doi":"10.18429/JACOW-IPAC2021-MOPAB142","DOIUrl":null,"url":null,"abstract":"It has been technically challenging to efficiently couple external radiofrequency (RF) power to cylindrical dielectric-loaded accelerating (DLA) structures, especially when the DLA structure has a high dielectric constant. This paper presents a novel design of matching section for coupling the RF power from a circular waveguide to an X-band DLA structure with a dielectric constant epsilon_r=16.66 and a loss tangent tan_delta=0.0000343. It consists of a very compact dielectric disk with a width of 2.035 mm and a tilt angle of 60 degree, resulting in a broadband coupling at a low RF field which has the potential to survive in the high-power environment. To prevent a sharp dielectric corner break, a 45 degree chamfer is also added. A microscale vacuum gap, caused by metallic clamping between the thin coating and the outer thick copper jacket, is also studied in detail. Through optimizations, more than 99% of RF power is coupled into the DLA structure, with the maximum electromagnetic fields located at a DLA structure. Tolerance studies on the geometrical parameters and mechanical design of the full-assembly structure are also carried out as a reference for realistic fabrication.","PeriodicalId":8436,"journal":{"name":"arXiv: Accelerator Physics","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":"{\"title\":\"A compact, low field, broadband matching section for externally-powered X-band dielectric-loaded accelerating structures\",\"authors\":\"Yelong Wei, A. Grudiev, B. Freemire, C. Jing\",\"doi\":\"10.18429/JACOW-IPAC2021-MOPAB142\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"It has been technically challenging to efficiently couple external radiofrequency (RF) power to cylindrical dielectric-loaded accelerating (DLA) structures, especially when the DLA structure has a high dielectric constant. This paper presents a novel design of matching section for coupling the RF power from a circular waveguide to an X-band DLA structure with a dielectric constant epsilon_r=16.66 and a loss tangent tan_delta=0.0000343. It consists of a very compact dielectric disk with a width of 2.035 mm and a tilt angle of 60 degree, resulting in a broadband coupling at a low RF field which has the potential to survive in the high-power environment. To prevent a sharp dielectric corner break, a 45 degree chamfer is also added. A microscale vacuum gap, caused by metallic clamping between the thin coating and the outer thick copper jacket, is also studied in detail. Through optimizations, more than 99% of RF power is coupled into the DLA structure, with the maximum electromagnetic fields located at a DLA structure. Tolerance studies on the geometrical parameters and mechanical design of the full-assembly structure are also carried out as a reference for realistic fabrication.\",\"PeriodicalId\":8436,\"journal\":{\"name\":\"arXiv: Accelerator Physics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2020-08-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"3\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv: Accelerator Physics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.18429/JACOW-IPAC2021-MOPAB142\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv: Accelerator Physics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.18429/JACOW-IPAC2021-MOPAB142","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
A compact, low field, broadband matching section for externally-powered X-band dielectric-loaded accelerating structures
It has been technically challenging to efficiently couple external radiofrequency (RF) power to cylindrical dielectric-loaded accelerating (DLA) structures, especially when the DLA structure has a high dielectric constant. This paper presents a novel design of matching section for coupling the RF power from a circular waveguide to an X-band DLA structure with a dielectric constant epsilon_r=16.66 and a loss tangent tan_delta=0.0000343. It consists of a very compact dielectric disk with a width of 2.035 mm and a tilt angle of 60 degree, resulting in a broadband coupling at a low RF field which has the potential to survive in the high-power environment. To prevent a sharp dielectric corner break, a 45 degree chamfer is also added. A microscale vacuum gap, caused by metallic clamping between the thin coating and the outer thick copper jacket, is also studied in detail. Through optimizations, more than 99% of RF power is coupled into the DLA structure, with the maximum electromagnetic fields located at a DLA structure. Tolerance studies on the geometrical parameters and mechanical design of the full-assembly structure are also carried out as a reference for realistic fabrication.