TY - CONF AU - Ristori, L. AU - Berrutti, P. AU - Castilla, A. AU - De Silva, S.U. AU - Delayen, J.R. AU - Huque, N.A. AU - Li, Z. AU - Narduzzi, M. AU - Ratti, A. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Development and Performance of RFD Crab Cavity Prototypes for HL-LHC AUP 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 US will be contributing to the HL-LHC upgrade at CERN with the fabrication and qualification of RFD crabbing cavities in the framework of the HL-LHC Accelerator Upgrade Project (AUP) managed by Fermilab. AUP received Critical Decision 3 (CD-3) approval by DOE in December 2020 launching the project into the production phase. The electro-magnetic design of the cavity was inherited from the LHC Accelerator Research Program (LARP) but needed to be revised to meet new project requirements and to prevent issues encountered during beam tests performed at CERN in the R&D phase. Two prototype cavities were manufactured in industry and cold tested. Challenges specific to the RFD cavity were the stringent interface tolerances, the pole symmetry and the higher-order-mode impedance spectrum. Chemical processing and heat treatments were performed initially at FNAL/ANL and are now being transferred to industry for the production phase. HOM dampers are manufactured and validated by JLAB. A summary of cold test results with and without HOM dampers is presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 531 EP - 535 KW - cavity KW - HOM KW - impedance KW - niobium KW - higher-order-mode DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-TUPTB046 UR - https://jacow.org/srf2023/papers/tuptb046.pdf ER - TY - CONF AU - Li, Z. AU - De Silva, S.U. AU - Delayen, J.R. AU - Rimmer, R.A. AU - Wu, Q. AU - Xiao, B.P. AU - Xu, W. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - EIC 197 MHz Crab Cavity RF Optimization 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 - Crab cavities, operating at 197 MHz and 394 MHz respectively, will be used to compensate the loss of luminosity due to a 25 mrad crossing angle at the interaction point in the Electron Ion Collider (EIC). Both crab cavities are of the RF Dipole (RFD) shape. To meet the machine design requirements, there are a few important cavity design considerations that need to be addressed. First, to achieve stable cavity operation at the design voltages, cavity geometry details must be optimized to suppress potential multipacting. Incorporating strong HOM damping in the cavity design is required for the beam stability and quality. Furthermore, due to the finite pole width, the multipole fields, especially the sextupole and the decapole terms, need to be minimized to maintain an acceptable beam dynamic aperture. This paper will present the RF optimization details of the 197 MHz cavity. PB - JACoW Publishing CP - Geneva, Switzerland SP - 584 EP - 588 KW - cavity KW - HOM KW - multipactoring KW - GUI KW - impedance DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-TUPTB068 UR - https://jacow.org/srf2023/papers/tuptb068.pdf ER - TY - CONF AU - Pudasaini, U. AU - Kelley, M.J. AU - Lechner, E.M. AU - Reece, C.E. AU - Trofimova, O. AU - Valente-Feliciano, A-M. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Surface Roughness Reduction and Performance of Vapor-Diffusion Coating of Nb₃Sn Film for SRF Application 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 - Nb₃Sn offers the prospect of better RF performance (Q and E_{acc}) than niobium at any given temperature because of its superior superconducting properties. Nb₃Sn-coated SRF cavities are routinely produced by growing a few microns thick Nb₃Sn film on Nb cavities via tin vapor diffusion. It has been observed that a clean and smooth surface can enhance the performance of the Nb₃Sn-coated cavity, typically, the attainable acceleration gradient. The reduction of surface roughness is often linked with a correlative reduction in average coating thickness and grain size. Besides Sn supply’s careful tuning, the temperature profiles were varied to reduce the surface roughness as low as ~40 nm in 20 µm × 20 µm AFM scans, one-third that of the typical coating. Samples were systematically coated inside a mock single-cell cavity and examined using different material characterization techniques. A few sets of coating parameters were used to coat 1.3 GHz single-cell cavities to understand the effects of roughness variation on the RF performance. This presentation will discuss ways to reduce surface roughness with results from a systematic analysis of the samples and Nb₃Sn-coated single-cell cavities. PB - JACoW Publishing CP - Geneva, Switzerland SP - 593 EP - 599 KW - cavity KW - SRF KW - site KW - accelerating-gradient KW - factory DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-WEIAA03 UR - https://jacow.org/srf2023/papers/weiaa03.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 - Hryhorenko, O. AU - Antoine, C.Z. AU - Dohmae, T. AU - Keckert, S. AU - Knobloch, J. AU - Kugeler, O. AU - Longuevergne, D. AU - Proslier, Th. AU - Éozénou, F. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Recent Advances in Metallographic Polishing for SRF Application 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 - This talk is an overview of the metallographic polishing R&D program covering Niobium and Copper substrates treatment for thin film coating as an alternative fabrication pathway for 1.3 GHz elliptical cavities. The presented research is the result of a collaborative effort between IJCLab, CEA/Irfu, HZB, and KEK in order to develop innovative surface processing and cavity fabrication protocols capable of meeting stringent requirements for SRF surfaces, including the reduction of safety risks and ecological footprint, enhancing reliability, improving the surface roughness, and potentially allowing cost reduction. The research findings will be disclosed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 646 EP - 650 KW - cavity KW - SRF KW - niobium KW - laser KW - framework DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-WEIXA06 UR - https://jacow.org/srf2023/papers/weixa06.pdf ER -