TY - CONF AU - Turner, D.A. AU - Gallifa Terricabras, A. AU - González Díaz-Palacio, I. AU - Hillert, W. AU - Koettig, T. AU - Macpherson, A. AU - Rosaz, G.J. AU - Stapley, N. AU - Wenskat, M. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Flux Expulsion Lens: Concept and Measurements 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 - A magnetic flux expulsion lens (MFEL) has been designed and built at CERN. This device uses closed topology conduction cooling of samples to quantify magnetic flux expulsion of superconductors, and allows for systematic measurements of the cooling dynamics and the magnetic response during the superconducting transition. Measurements for bulk Nb, cold worked Nb, sputtered Nb on Cu, and SIS multilayer structures are given. Preliminary results for both sample characterization of expulsion dynamics, and observation of an enhanced flux expulsion in SIS samples are also reported. PB - JACoW Publishing CP - Geneva, Switzerland SP - 56 EP - 61 KW - FEL KW - cavity KW - niobium KW - site KW - SRF DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-MOPMB003 UR - https://jacow.org/srf2023/papers/mopmb003.pdf ER - TY - CONF AU - Swieszek, J.S. AU - Gallifa Terricabras, A. AU - Garlasché, M. AU - Smakulska, D. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Novel Approaches in Characterization and Modelling of Fabrication Processes for SRF Components 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 - In the past years, Finite Element Methods have been increasingly applied at CERN, with the aim of modelling fabrication processes for SRF components. Currently, many large deformation processes such as deep drawing, forging, hydroforming, and spinning, are being simulat-ed. Taking the initial trials out of the workshop via simu-lation has proven very efficient for steering fabrication strategy, avoiding unnecessary trials, and helping to re-duce time and costs. This contribution will present a novel approach for studying fabrication process feasibil-ity and failure prediction using numerical tools, based on the Forming Limit Diagram method, developed for OFE copper sheets. This contribution will show the applica-tion of the mentioned method on the study of tubular hydroforming, as an alternative way to produce seamless elliptical RF cavities. Analysis of past hydroforming trials is also discussed, together with the comparison of different fabrication strategies. PB - JACoW Publishing CP - Geneva, Switzerland SP - 490 EP - 495 KW - cavity KW - SRF KW - simulation KW - FEM KW - experiment DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-TUPTB038 UR - https://jacow.org/srf2023/papers/tuptb038.pdf ER - TY - CONF AU - Vega Cid, L. AU - Atieh, S. AU - Bellini, G. AU - Bianchi, A. AU - Ferreira, L.M.A. AU - Leith, S.B. AU - Pereira Carlos, C. AU - Rosaz, G.J. AU - Venturini Delsolaro, W. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Results of the R&D RF Testing Campaign of 1.3 GHz Nb/Cu Cavities 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 - In the context of the R&D program on Nb/Cu carried out at CERN, a total of 25 tests have been performed since 2021. This talk will present these results. Three different manufacturing techniques have been used to produce the copper substrates, in order to investigate which is the most suitable in terms of quality and economy of scale. On one hand, the focus has been on optimizing the surface resistance at 4.2K, as this will be the operating temperature of FCC. The results at this temperature are encouraging, showing repeatable and optimized RF performance. On the other hand, RF tests have been done at 1.85 K too aiming at deepening the knowledge of the mechanisms behind the Q slope. This is key to work on the mitigation of this phenomenon and ultimately to extend the application of this technology to high energy, high gradient accelerators. The influence of the thermal cycles has been thoroughly investigated. A systematic improvement has been observed of both the Q slope and the residual resistance with slow thermal cycles. PB - JACoW Publishing CP - Geneva, Switzerland SP - 621 EP - 626 KW - cavity KW - SRF KW - niobium KW - operation KW - cryogenics DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-WEIXA02 UR - https://jacow.org/srf2023/papers/weixa02.pdf ER - TY - CONF AU - Gallifa Terricabras, A. AU - Aviles Santillana, I. AU - Barrière, S. AU - Cano-Pleite, E. AU - Garlasché, M. AU - Narduzzi, M. AU - Pfeiffer, S. AU - Prever-Loiri, L. AU - Swieszek, J.S. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Optimizing the Manufacture of High-Purity Niobium SRF Cavities Using the Forming Limit Diagram: A Case Study of the HL-LHC Crab Cavities RFD Pole 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 Crab Cavities are key components of the High Luminosity Large Hadron Collider (HL-LHC) project at CERN, which aims to increase the integrated luminosity of the LHC, the world’s largest particle accelerator, by a factor of ten. This paper explores the application of the Forming Limit Diagram (FLD) to enhance the manufacturing process of complex-shape Nb-based cavities, with a focus on the formability challenges experienced with the pole of the Radio Frequency Dipole (RFD) Crab Cavities. The study includes the material characterization of ultra-high-purity niobium (Nb RRR300) sheets, namely mechanical tests and microstructural analysis; it also contains large-deformation Finite Element simulations of the pole deep drawing process, and the translation of the resulting strains in a FLD diagram, together with several suggestions on how to improve the manufacturing process of such deep drawn parts. The results of this study can provide valuable insights into improving the design and fabrication of complex-shaped superconducting radio-frequency cavities made by large-deformation metal-sheet forming processes. PB - JACoW Publishing CP - Geneva, Switzerland SP - 627 EP - 633 KW - cavity KW - simulation KW - niobium KW - SRF KW - luminosity DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-WEIXA03 UR - https://jacow.org/srf2023/papers/weixa03.pdf ER - TY - CONF AU - Kumar, A. AU - Araki, H. AU - Dohmae, T. AU - Ito, H. AU - Saeki, T. AU - Umemori, K. AU - Yamamoto, A. AU - Yamanaka, M. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Development of the Directly-Sliced Niobium Material for High Performance SRF Cavities 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 - For the purpose of cost reduction for the ILC, KEK has been conducting R&D on direct sliced Nb materials such as large grain and medium grain Nb. Single-cell, 3-cell, and 9-cell cavities have been manufactured, and each has demonstrated a high-performance accelerating gradient exceeding 35 MV/m. The results of applying high-Q/high-G recipes, such as two-step baking and furnace baking to these cavities are also shown. Moreover, mechanical tests have been carried out for the beforementioned materials to evaluate their strength for application to the High-Pressure Gas Safety Law. The status of development of these large grain and Medium grain Nb will be presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 634 EP - 640 KW - cavity KW - SRF KW - niobium KW - collider KW - linear-collider DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-WEIXA04 UR - https://jacow.org/srf2023/papers/weixa04.pdf ER - TY - CONF AU - Bira, S. AU - Ge, M. AU - Valente-Feliciano, A-M. AU - Vega Cid, L. AU - Venturini Delsolaro, W. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Geometry Optimization for a Quadrupole Resonator at Jefferson Lab 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 quadrupole resonator (QPR) is a sample characterization tool to measure the RF properties of superconducting materials using the calorimetry method at different temperatures, magnetic fields, and frequencies. Such resonators are currently operating at CERN and HZB but suffer from Lorentz force detuning and modes overlapping, resulting in higher uncertainties in surface resistance measurement. Using the two CERN’s QPR model iterations, the geometry was optimized via electromagnetic and mechanical simulations to eliminate these issues. The new QPR version was modeled for an increasing range of magnetic fields. The magnetic field is concentrated at the center of the sample to reduce the uncertainty in surface resistance measurements significantly. This paper will discuss the QPR geometry optimization for the new version of QPR, which is now progressing towards fabrication. PB - JACoW Publishing CP - Geneva, Switzerland SP - 670 EP - 673 KW - quadrupole KW - SRF KW - simulation KW - cavity KW - ECR DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-WEPWB048 UR - https://jacow.org/srf2023/papers/wepwb048.pdf ER - TY - CONF AU - Barbagallo, C. AU - Barriere, B.S. AU - Clement, C.S. AU - Duchesne, P. AU - Gerard, R.L.A. AU - Gerigk, F. AU - Henry, J. AU - Kaabi, W. AU - Maurin, P.M. AU - Olivier, G. AU - Olry, G. AU - Overstreet, S.A. AU - Park, G.-T. AU - Rimmer, R.A. AU - Roset, S. AU - Wang, H. AU - Zomer, Z.F. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Simulations and First RF Measurements of Coaxial HOM Coupler Prototypes for PERLE SRF Cavities 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 Radio-Frequency (SRF) linac cryomodules are foreseen for the high-current multi-turn energy recovery linac PERLE (Powerful Energy Recovery Linac for Experiments). Coaxial higher order mode (HOM) couplers are the primary design choice to absorb beam-induced power and avoid beam instabilities. We have used 3D-printed and copper-coated HOM couplers for the prototyping and bench RF measurements on the copper PERLE cavities. We have started a collaboration with JLab and CERN on this effort. This paper presents electromagnetic simulations of the cavity HOM-damping performance on those couplers. Bench RF measurements of the HOMs on an 801.58 MHz 2-cell copper cavity performed at JLab are detailed. The results are compared to eigenmode simulations in CST to confirm the design. RF-thermal simulations are conducted to investigate if the studied HOM couplers undergo quenching. PB - JACoW Publishing CP - Geneva, Switzerland SP - 831 EP - 834 KW - HOM KW - cavity KW - damping KW - coupling KW - simulation DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-WEPWB103 UR - https://jacow.org/srf2023/papers/wepwb103.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 - TY - CONF AU - McIntosh, P.A. AU - Belomestnykh, S.A. AU - Burt, G. AU - Calaga, R. AU - De Silva, S.U. AU - Delayen, J.R. AU - Gonin, I.V. AU - Khabiboulline, T.N. AU - Lunin, A. AU - Okugi, T. AU - Orlov, Y.M. AU - Verdú-Andrés, S. AU - Xiao, B.P. AU - Yakovlev, V.P. AU - Yamamoto, A. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Crab Cavities for ILC 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 - For the 14 mrad crossing angle proposed, crab cavity systems are fundamentally anticipated for the viable operation of the International Linear Collider (ILC), in order to maximise its luminosity performance. Since 2021, a specialist development team have been defining optimum crab cavity technologies which can fulfil the operational requirements for ILC, both for its baseline centre-of-mass energy of 250 GeV, but also extending those requirements out to higher beam collision intensities. Five design teams have established crab cavity technology solutions, which have the capability to also operate up to 1 TeV centre-of-mass. This presentation showcases the key performance capabilities of these designs and their associated benefits for both manufacture and integration into the ILC Interaction Region. The recommended outcome of the recently conducted crab cavity technology down-selection, will also be highlighted. PB - JACoW Publishing CP - Geneva, Switzerland SP - 990 EP - 998 KW - cavity KW - HOM KW - SRF KW - operation KW - impedance DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-FRIBA04 UR - https://jacow.org/srf2023/papers/friba04.pdf ER -