TY - CONF AU - Leicester, N.L. AU - Burt, G. AU - Chyhyrynets, E. AU - Conlon, J.A. AU - Malyshev, O.B. AU - Marks, H.S. AU - Pira, C. AU - Seal, D.J. AU - Sian, B.S. AU - Valizadeh, R. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Development and Testing of Split 6 GHz Cavities With Niobium Coatings J2 - Proc. of SRF2023, Grand Rapids, MI, USA, 25-30 June 2023 CY - Grand Rapids, MI, USA T2 - International Conference on RF Superconductivity T3 - 21 LA - english AB - Superconducting thin-films on a copper substrate are used in accelerator RF cavities as an alternative to bulk Nb due to the high thermal conductivity of copper and the lower production costs. Although thin-film coated RF cavities can match, or even exceed the performance of bulk Nb, there are some challenges around the deposition. The RF cavities are often produced as two half-cells with a weld across the centre where the RF surface current is highest, which could reduce cavity performance. To avoid this, a cavity can be produced in 2 longitudinally split halves, with the join parallel to the surface current. As the current doesn’t cross the join a simpler weld can be performed far from the fields, simplifying the manufacturing process, and potentially improving the cavities performance. This additionally allows for different deposition techniques and coating materials to be used, as well as easier post-deposition quality control. This paper discusses the development and testing of 6 GHz cavities that have been designed and coated at the Cockcroft Institute, using low temperature RF techniques to characterise cavities with different substrate preparations and coating techniques. PB - JACoW Publishing CP - Geneva, Switzerland SP - 51 EP - 55 KW - cavity KW - SRF KW - coupling KW - target KW - site DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-MOPMB001 UR - https://jacow.org/srf2023/papers/mopmb001.pdf ER - TY - CONF AU - Benjamin, C. AU - Burt, G. AU - Conlon, J.A. AU - Leicester, N.L. AU - Malyshev, O.B. AU - Marks, H.S. AU - Seal, D.J. AU - Smith, L.G.P. AU - Valizadeh, R. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Deposition and Characterisation of V₃Si films for SRF Applications J2 - Proc. of SRF2023, Grand Rapids, MI, USA, 25-30 June 2023 CY - Grand Rapids, MI, USA T2 - International Conference on RF Superconductivity T3 - 21 LA - english AB - A15 superconducting materials, like V₃Si and Nb₃Sn, are potential alternatives to Nb for next generation thin film SRF cavities when operated at 4 K. Their relatively high Tc and superconducting properties could allow for higher accelerating gradients and elevated operating temperatures. We present work on the deposition of V₃Si thin films on planar Cu substrates and an open structure 6 GHz cavity, using physical vapour deposition (PVD) and a V₃Si single target. The surface structure, composition and DC superconducting properties of two planar samples were characterised via secondary electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX) and in a magnetic field penetration facility. Furthermore, the first deposition using PVD of a V₃Si film on a 6 GHz split cavity and the RF performance is presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 84 EP - 87 KW - cavity KW - SRF KW - site KW - target KW - vacuum DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-MOPMB011 UR - https://jacow.org/srf2023/papers/mopmb011.pdf ER - TY - CONF AU - Smith, L.G.P. AU - Burt, G. AU - Junginger, T. AU - Malyshev, O.B. AU - Turner, D.A. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Investigation, Using Nb Foils to Characterise the Optimal Dimensions of Samples Measured by the Magnetic Field Penetration Facility J2 - Proc. of SRF2023, Grand Rapids, MI, USA, 25-30 June 2023 CY - Grand Rapids, MI, USA T2 - International Conference on RF Superconductivity T3 - 21 LA - english AB - SRF cavities made of bulk Nb are reaching their theoretical limits in the maximum accelerating gradient, E_{acc}, where E_{acc} is limited by the maximum magnetic field, Bmax, that can be applied on the surface of the accelerating cavity wall. To increase E_{acc}, Bmax, which can be applied to the surface, must also be increased. The A15 materials or multilayer structures are the potential solution to increase Bmax. Since coating and RF testing of full size RF cavities is both expensive and time consuming, one need to evaluate new ideas in superconducting thin films quickly and at low cost. A magnetic field penetration experiment has been designed and built at Daresbury Laboratory to test small superconducting samples. The facility produces a parallel DC magnetic field, which applied from one side of the sample to the other similar to that in an RF cavity. The facility applies an increasing magnetic field at a set temperature to determine the field of full flux penetration which can give an insight into the quality and structure of the superconducting structure. The facility has been characterised using both type I and II superconductors and is now producing results from novel materials. PB - JACoW Publishing CP - Geneva, Switzerland SP - 88 EP - 91 KW - cavity KW - SRF KW - experiment KW - ECR KW - niobium DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-MOPMB012 UR - https://jacow.org/srf2023/papers/mopmb012.pdf ER - TY - CONF AU - Pira, C. AU - Antoine, C.Z. AU - Azzolini, O. AU - Benjamin, C. AU - Berry, S. AU - Berton, R. AU - Bertucci, M. AU - Bonesso, M. AU - Bradley, J.W. AU - Burt, G. AU - Caforio, R. AU - Candela, S. AU - Candela, V. AU - Chyhyrynets, E. AU - Dima, R. AU - Favero, G. AU - Fonnesu, D. AU - Ford, D. AU - Garcia, V.A. AU - Hryhorenko, O. AU - Jiang, X. AU - Kalboussi, Y. AU - Keckert, S. AU - Keppel, G. AU - Knobloch, J. AU - Kugeler, O. AU - Leicester, N.L. AU - Longuevergne, D. AU - Malyshev, O.B. AU - Marconato, G. AU - Marks, N. AU - Medvids, A. AU - Mychko, A. AU - Onufrijevs, P. AU - Paparella, R. AU - Pepato, A. AU - Piccoli, D. AU - Piccoli, F. AU - Proslier, Th. AU - Prucnal, S. AU - Rebesan, P. AU - Ries, R. AU - Romanato, M. AU - Salmaso, A. AU - Seal, D.J. AU - Seiler, E. AU - Sian, B.S. AU - Simon, S. AU - Smith, L.G.P. AU - Squizzato, G. AU - Staedler, T. AU - Stivanello, F. AU - Telatin, F. AU - Turner, D.A. AU - Valente-Feliciano, A-M. AU - Valizadeh, R. AU - Zhou, S. AU - Zubtsovskii, A.O. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Progress in European Thin Film Activities J2 - Proc. of SRF2023, Grand Rapids, MI, USA, 25-30 June 2023 CY - Grand Rapids, MI, USA T2 - International Conference on RF Superconductivity T3 - 21 LA - english AB - Thin-film cavities with higher Tc superconductors (SC) than Nb promise to move the operating temperature from 2 to 4.5 K with savings 3 orders of magnitude in cryogenic power consumption. Several European labs are coordinating their efforts to obtain a first 1.3 GHz cavity prototype through the I.FAST collaboration and other informal collaborations with CERN and DESY. R&D covers the entire production chain. In particular, new production techniques of seamless Copper and Niobium elliptical cavities via additive manufacturing are studied and evaluated. New acid-free polishing techniques to reduce surface roughness in a more sustainable way such as plasma electropolishing and metallographic polishing have been tested. Optimization of coating parameters of higher Tc SC than Nb (Nb₃Sn, V₃Si, NbTiN) via PVD and multilayer via ALD are on the way. Finally, rapid heat treatments such as Flash Lamp Annealing and Laser Annealing are used to avoid or reduce Cu diffusion in the SC film. The development and characterization of SC coatings is done on planar samples, 6 GHz cavities, choke cavities, QPR and 1.3 GHz cavities. This work presents the progress status of these coordinated efforts. PB - JACoW Publishing CP - Geneva, Switzerland SP - 607 EP - 614 KW - cavity KW - SRF KW - target KW - niobium KW - laser DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-WECAA01 UR - https://jacow.org/srf2023/papers/wecaa01.pdf ER - TY - CONF AU - Turaj, K. AU - Bastard, J. AU - Calaga, R. AU - Calvo, S.J. AU - Capatina, O. AU - Castilla, A. AU - Chiodini, M. AU - Duval, C. AU - Edwards, A.V. AU - Ferreira, L.M.A. AU - Gourragne, M. AU - Kohler, P. AU - Montesinos, E. AU - Pasquino, C. AU - Pechaud, G. AU - Stapley, N. AU - Valverde Alonso, N. AU - Walker, J.D. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - RF Performance Results of RF Double Quarter Wave Resonators for LHC High Luminosity Project J2 - Proc. of SRF2023, Grand Rapids, MI, USA, 25-30 June 2023 CY - Grand Rapids, MI, USA T2 - International Conference on RF Superconductivity T3 - 21 LA - english AB - The LHC High Luminosity (HL-LHC) project includes, among other key items, the installation of superconducting crab cavities in the LHC machine. The Double Quarter Wave (DQW) crab cavity will be utilised to compensate for the effects of the vertical crossing angle. Two bare DQW series cavities were manufactured in Germany by RI Research Instruments and validated successfully at CERN through a cold test at 2K. Two DQW series cavities were produced in-house at CERN, integrated into a titanium helium tank, and equipped with RF ancillaries. This paper addresses the cavities preparation processes and summarizes the results of cryogenic tests of DQW cavities at CERN PB - JACoW Publishing CP - Geneva, Switzerland SP - 925 EP - 931 KW - cavity KW - HOM KW - luminosity KW - vacuum KW - radiation DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-THIAA02 UR - https://jacow.org/srf2023/papers/thiaa02.pdf ER -