Elimination of defects in a welded joint in a niobium superconducting resonator
https://doi.org/10.29235/1561-8358-2023-68-1-18-23
Abstract
The possible reasons for the appearance of defects during welding of a niobium superconducting coaxial halfwave resonator (HWR) are investigated, which consist in the deviation of the shape of the welded surface from the given one, in the deviation of the angle of incidence of the beam from the perpendicular to the welded surface, in fluctuations in the thickness of the welded edges, and also the presence of some instability (pulsation) accelerating voltage, beam currents and focusing of the electron beam gun. The possibilities of preventing the appearance of defects during welding are determined, which consist in regulating the operating parameters of the electron beam gun depending on possible errors in the manufacture and preparation of the welded edges. Methods for elimination of defects in welding of niobium superconducting coaxial HWR are studied. A method has been developed for repairing defects in welded joints such as burn-throughs on the type of resonator under study using electron-beam deposition. The results of measuring the resonant frequency of the HWR before the onset and after the recovery of burn-through are presented, which showed that the melting of the hole did not lead to a change in the electrical characteristics. Vacuum and cryogenic tests at liquid nitrogen temperature confirmed the tightness of the welded joints. The results obtained can be used in the development of basic technologies for the restoration and repair of expensive and difficult-to-manufacture elements of accelerator technology – superconducting high-frequency resonators made of high-purity niobium sheet.
About the Authors
A. A. Burin
Physical-Technical Institute of the National Academy of Sciences
Belarus
Belarus
Alexander А. Burin – Researcher
10, Academician Kuprevich Str., 220084, Minsk
V. G. Zaleski
Physical-Technical Institute of the National Academy of Sciences
Belarus
Belarus
Vitali G. Zaleski – Dr. Sci. (Physics and Mathematics), Director
10, Academician Kuprevich Str., 220084, Minsk
I. L. Pobol
Physical-Technical Institute of the National Academy of Sciences
Russian Federation
Russian Federation
Igor L. Pobol – Dr. Sci. (Engineering), Professor, Head of the Department
10, Academician Kuprevich Str., 220084, Minsk
References
1. Pobol I. L., Yurevich S. V. Developing of superconducting niobium cavities for accelerators. Journal of Physics: Conference Series, 2015, vol. 653, no. 1, art. ID 012008. http://doi.org/10.1088/1742-6596/653/1/012008
2. Butenko A. V., Emelianov N. E., Sidorin A. O., Syresin E. M., Trubnikov G. V., Gusarova M. A., Kulevoy T. V., et al. Status of R&D on new superconducting injector linac for Nuclotron-NICA. 61st ICFA Advanced Beam Dynamics Workshop on HighIntensity and High-Brightness Hadron Beams, Daejeon, Korea, 17–22 June 2018: Proceedings. Daejeon, 2018, рp. 83–87. http://doi.org/10.18429/JACoW-HB2018-TUA2WC02
3. Gusarova M. A., Lalayan M. V., Nemchenko R. E., Polozov S. M., Butenko A. V., Syresin E. M., Bychenok D. S., et al. Current state of work on the creation of superconducting accelerating cavities for the Nuclotron-Nica project. VII Mezhdunarodnaya konferentsiya “Lazernye, plazmennye issledovaniya i tekhnologii” (Laplaz-2021), Moskva, NIYaU MIFI, 24–26 marta 2021 g. [7th International Conference “Laser, Plasma Research and Technologies” (Laplaz-2021), Moscow, MEPhI Research Institute, March 24–26, 2021]. Moscow, 2021, pp. 112–114 (in Russian).
4. Gao J., Zhai J. Y., Li Z. Q., Zhao T. X., Dai J. P., Wang Q. Y., Guo Z. D., et al. IHEP low-loss large grain 9-cell cavity fabrication and processing. 1st International Particle Accelerator Conference (IPAC’10), Kyoto, Japan, May 23–28, 2010: Proceedings. Geneva, 2010, pp. 2974–2976.
5. Navitski A., Elsen E., Foster B., Iversen J., Laasch R., Matheisen A., Reschke D., et al. ILC-higrade cavities as a tool of quality control for European XFEL. 16th International Conference on RF Superconductivity, SRF 2013, Paris, France, 23–27 September 2013: Proceedings. 2013, pp. 209–212.
6. Ristori L., Awida M. H., Berrutti P., Khabiboulline T. N., Merio M., Passarelli D., Rowe A., Sergatskov D. A., Suk hanov A. I. Fabrication and testing of SSR1 resonators for PXIE. 4th International Particle Accelerator Conference, IPAC 2013, Shanghai, China, 12–17 May, 2013: Proceedings. Geneva, JACOW, 2013, pp. 2429–2431.
7. Ristori L., Awida M. H., Berrutti P., Ginsburg C. M., Gonin I. V., Khabiboulline T. N., Merio M., et al. Development and performance of 325 MHz single spoke resonators for Project X. 16th International Conference on RF Superconductivity, SRF 2013, Paris, France, 23–27 September 2013: Proceedings, 2013, pp. 1187–1192.
8. Dohmae T., Inoue H., Umemori K., Watanabe Y., Yamanaka M. KEK Production and investigation of superconducting 9-cell cavity made of large grain Nb in KEK. 7th International Particle Accelerator Conference, IPAC 2016, Busan, Korea, 8–13 May, 2016: Proceedings. Geneva, 2016, pp. 2141–2144.
9. Ciovati G., Anderson A., Clemens W., Combs D., Davis K., Dail J., Dreyfuss C., et al. Experience with the fabrication, processing and testing of the prototype “C75” 5-cell cavities. JLAB-TN-17-029, May 17, 2017. Available at: https://indico.jlab.org/event/251/attachments/2501/3068/FabricationProcessTesting_of_C75-JLAB-TN-17-029.pdf (accessed 22 October 2022).
10. Singer W., Brinkmann A., Brinkmann R., Iversen J., Matheisen A., Moeller W.-D., Navitski A., et al. Production of superconducting 1.3-GHz cavities for the European X-ray Free Electron Laser. Physical Review Accelerators and Beams, 2016, vol. 19, art. ID 092001. https://doi.org/10.1103/PhysRevAccelBeams.19.092001
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