TY  - CONF
AU  - Schmidt, Ch.
AU  - Bousonville, M.
AU  - Branlard, J.
AU  - Diomede, M.
AU  - Göller, S.
AU  - Kostin, D.
AU  - Scholz, M.
AU  - Vogel (Fogel), V.
AU  - Walker, N.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - Operational Experience with the European XFEL SRF Linac
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 European X-ray Free Electron laser (EuXFEL) is a 3.4 km long research facility which generates ultrashort X-ray flashes of outstanding brilliance since 2017. Up to 27000 electron bunches per second are accelerated in a 1.3 km long superconducting radio frequency (SRF) linac to a maximum energy of 17.6 GeV. Within this time, operational experience with a pulsed RF machine has been gained and new operation modes simultaneously delivering electron bunches to 3 different SASE undulator beamlines have been successfully implemented. Recent activities on increasing the linac availability, power efficiency and duty cycle are discussed.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 43
EP  - 50
KW  - operation
KW  - cavity
KW  - FEL
KW  - linac
KW  - LLRF
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-MOIXA06
UR  - https://jacow.org/srf2023/papers/moixa06.pdf
ER  - 

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  - Ghanbari, R.
AU  - Bate, C.
AU  - Deyu, G.K.
AU  - Hillert, W.
AU  - Monroy-Villa, R.
AU  - Reschke, D.
AU  - Steder, L.
AU  - Wenskat, M.
AU  - Wolff, J.C.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - Correlating Lambda Shift Measurements with RF Performance in Mid-T Heat Treated 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  - Heat treatment procedures have been identified as cru-cial for the performance of niobium SRF cavities, which are the key technology of modern accelerators. The so called "mid-T heat treatments", invert the dependence of losses on the applied accelerating field (anti-Q slope) and significantly reduce the absolute value of losses. The mechanism behind these improvements is still under investigation, and further research is needed to fully understand the principle processes involved. Anomalies in the frequency shift near the transition temperature (Tc), known as "dip" can provide insight into fundamental material properties and allow us to study the relation-ship of frequency response with surface treatments. Therefore, we have measured the frequency versus temperature of multiple mid-T heat treated cavities with different recipes and studied the correlation of SRF properties with frequency shift features. The maximum quality factor correlates with two such shift features, namely the dip magnitude per temperature width and the total frequency shift.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 124
EP  - 128
KW  - cavity
KW  - SRF
KW  - niobium
KW  - radio-frequency
KW  - ECR
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-MOPMB021
UR  - https://jacow.org/srf2023/papers/mopmb021.pdf
ER  - 

TY  - CONF
AU  - Bate, C.
AU  - Reschke, D.
AU  - Schaffran, J.
AU  - Steder, L.
AU  - Trelle, L.
AU  - Weise, H.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - Recent mid-T Single-Cell Treatments R&D at DESY
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 challenge of improving the performance of SRF cavities is being faced worldwide. One approach is to modify the superconducting surface properties through certain baking procedures. Recently a niobium retort furnace placed directly under an ISO4 clean room has been refurbished at DESY. Thanks to an inter-vacuum chamber and cryopumps, with high purity values in the mass spectrum it is working in the UHV range of 2·10⁻⁸ mbar. The medium temperature (mid-T) heat treatments around 300°C are promising and successfully deliver reproducible very high Q₀ values of 2-5·10¹0 at medium field strengths of 16 MV/m. Since the first DESY and ZRI mid-T campaign yielded promising results, further results of 1.3 GHz single-cell cavities are presented here after several modified treatments of the mid-T recipe. In addition, samples were added to each treatment, the RRR value change was examined, and surface analyses were subsequently performed. The main focus of the sample study is the precise role of the changes in the concentration of impurities on the surface. In particular, the change in oxygen content due to diffusion processes is suspected to be the cause of enhancing the performance.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 129
EP  - 134
KW  - cavity
KW  - niobium
KW  - SRF
KW  - vacuum
KW  - controls
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-MOPMB022
UR  - https://jacow.org/srf2023/papers/mopmb022.pdf
ER  - 

TY  - CONF
AU  - Wiencek, M.
AU  - Kasprzak, K.
AU  - Kostin, D.
AU  - Reschke, D.
AU  - Steder, L.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - Summary of the Superconducting Rf Measurements in AMTF Hall at DESY
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 AMTF (Accelerator Module Test Facility) in DESY was built for the tests of all superconducting cavities and cryomodules for the EuXFEL linac. After successful commissioning of the EuXFEL, the AMTF has been adapted in order to perform SRF (super conducting radio frequency) measurements of cavities and accelerating modules for different projects. Several SRF cavities related projects are still ongoing, while other were just finished. Some of those projects are dedicated to test components for the infrastructure of accelerators which are under construction, while the other ones are devoted to new R&D paths aiming for cavities and modules with high performance which are under investigation at DESY. This paper describes present activities performed at AMTF with special emphasis on performing SRF measurements for the ongoing cavities production. Most of the presented data is related to vertical cryostat cavity testing. However, some data about cryomodules and a new coupler test stand will be shown as well. Detailed statistics about the number of vertical tests performed within the last two years are also presented.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 248
EP  - 252
KW  - cavity
KW  - SRF
KW  - cryomodule
KW  - FEL
KW  - superconductivity
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-MOPMB058
UR  - https://jacow.org/srf2023/papers/mopmb058.pdf
ER  - 

TY  - CONF
AU  - Wheelhouse, A.E.
AU  - Akintola, A.E.T.
AU  - Blackett-May, A.J.
AU  - Ellis, M.J.
AU  - Hitchen, S.
AU  - Hornickel, P.C.
AU  - Jenkins, C.R.
AU  - Lowe, M.
AU  - Mason, D.A.
AU  - McIntosh, P.A.
AU  - Middleman, K.J.
AU  - Miller, G.
AU  - Mutch, J.
AU  - Oates, A.
AU  - Pattalwar, S.M.
AU  - Pendleton, M.D.
AU  - Poynton, J.O.W.
AU  - Reschke, D.
AU  - Skachko, I.M.
AU  - Smith, P.A.
AU  - Steder, L.
AU  - Templeton, N.
AU  - Wiencek, M.
AU  - Wilde, S.
AU  - Wilson, J.T.G.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - Provision of High Beta Cavities for European Spallation Source by UKRI-STFC Daresbury Laboratory
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  - As part of the requirement for the European Spallation Source (ESS) facility in Lund, Sweden, a project has been undertaken by Accelerator Science and Technology Cen-tre (ASTeC) as part of a UK In Kind Contribution to pro-vide 84 704 MHz High-Beta superconducting RF cavities. The project has included the procurement of niobium and the testing of cavities at Daresbury Laboratory and Deutsches Elektronen-Synchrotron (DESY), in prepara-tion for integration into the cryomodules which is being performed at Commissariat à l¿Energie Atomique et aux Energies Alternatives (CEA) Saclay, France. To date all the cavities have been manufactured in industry apart from the final cavity and 3 cavities remain to be tested. An overview of the experiences for the provision of these cavities is described.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 286
EP  - 289
KW  - cavity
KW  - radiation
KW  - ion-source
KW  - cryomodule
KW  - accelerating-gradient
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-MOPMB075
UR  - https://jacow.org/srf2023/papers/mopmb075.pdf
ER  - 

TY  - CONF
AU  - Kostin, D.
AU  - Barbanotti, S.
AU  - Eschke, J.
AU  - Jensch, K.
AU  - Krupka, N.
AU  - Muhs, A.
AU  - Reschke, D.
AU  - Saegebarth, S.
AU  - Schaffran, J.
AU  - Schilling, P.
AU  - Schmökel, M.
AU  - Steder, L.
AU  - Steinhau-Kühl, N.
AU  - Sulimov, A.
AU  - Vogel, E.
AU  - Weise, H.
AU  - Wiencek, M.
AU  - van der Horst, B.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - SRF Accelerating Modules Upgrade for Flash Linac at DESY
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 accelerating modules with 8 TESLA-type 1.3 GHz SRF cavities are the main part of the linear accelerators currently in user operation at DESY, FLASH [1, 2] and the European XFEL [3, 4]. For the FLASH upgrade in 2022 [5] two accelerating modules have been exchanged in order to enhance the beam energy to 1.3 GeV. The two modules have been prototype modules for the European XFEL. After reassembly both modules were successfully tested and installed in the FLASH linac. Data taken during the commissioning at the end of 2022 did confirm the test results. This paper presents described efforts and their conclusions since last two years and continues the presentation given at SRF 2021 [6].
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 306
EP  - 310
KW  - cavity
KW  - SRF
KW  - FEL
KW  - linac
KW  - radiation
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-MOPMB082
UR  - https://jacow.org/srf2023/papers/mopmb082.pdf
ER  - 

TY  - CONF
AU  - Barbanotti, S.
AU  - Abassi, DESY.
AU  - Bozhko, Y.
AU  - Honkavaara, K.
AU  - Jensch, K.
AU  - Kostin, D.
AU  - Lederer, S.
AU  - Roßbach, J.
AU  - Schnautz, T.
AU  - Schreiber, S.
AU  - Wagner, A.
AU  - Weise, H.
AU  - Zajac, J.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - Twenty Years of Cryogenic Operation of the Flash Superconducting Linac
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 FLASH superconducting linac is in operation at DESY since more than 20 years. Many changes and upgrades took place to transform a test stand for single cryomodules to a successful free electron laser. We summarize here the main steps of the FLASH history from the cryogenic point of view including the latest major upgrade that took place in 2022. We also give an overview of cryomodule performances like cavity gradient and heat load measurements and their evolution over the time.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 347
EP  - 353
KW  - cryomodule
KW  - linac
KW  - cavity
KW  - FEL
KW  - operation
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-TUIAA01
UR  - https://jacow.org/srf2023/papers/tuiaa01.pdf
ER  - 

TY  - CONF
AU  - Vogt, M.
AU  - Ferrari, E.
AU  - Gerth, C.
AU  - Honkavaara, K.
AU  - Rönsch-Schulenburg, J.
AU  - Schaper, L.
AU  - Schreiber, S.
AU  - Zemella, J.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - The FLASH 2020+ Upgrade 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  - FLASH, the Soft X-Ray and Extreme-UV Free Electron Laser at DESY, is undergoing a substantial upgrade and refurbishment project, called FLASH2020+. The project will finally enable external seeded and SASE FEL operation for a wavelength range down to 4 nm with the EEHG method. A key ingredient of the upgrade was replacing two early TTF-type L-band RF cryo accelerator modules by modern, high-gradient XFEL-type ones. The beam energy range of the injector has been increased by 100 MeV. This was achieved in the first of two long shutdowns from November 2021 to August 2022. The energy increase together with an afterburner APPLE III type undulator for variable circular polarization in the FLASH2 beamline will make it possible to reach the oxygen K-edge (530 eV). This talk will report on the project and the first shutdown with emphasis on the upgraded modules.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 354
EP  - 360
KW  - laser
KW  - FEL
KW  - electron
KW  - undulator
KW  - operation
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-TUIAA02
UR  - https://jacow.org/srf2023/papers/tuiaa02.pdf
ER  - 

TY  - CONF
AU  - Trelle, L.
AU  - Bate, C.
AU  - Remde, H.
AU  - Reschke, D.
AU  - Schaffran, J.
AU  - Steder, L.
AU  - Weise, H.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - Refurbishment and Reactivation of a Niobium Retort Furnace at DESY
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 research in the field of heat treatments of supercon-ducting cavities, a niobium ultra-high vacuum furnace built in 1992 - originally used for the titanization of 1.3 GHz nine-cell cavities - and later shut down was recently refurbished and reactivated. A significant upgrade is the ability to run the furnace in partial pressure mode with nitrogen. The furnace is connected directly to the ISO4 area of the clean room for cavity handling. At room temperature vacuum values of around 3×10⁻⁸ mbar are achieved. The revision included the replacement of the complete control system and a partial renewal of the pump technology. The internal mounting structures are optimized for single-cell operation including tandem operation (two single-cell cavities at once) and corresponding accessories such as witness-samples and caps for the cavities. The installation of additional thermocouples for a detailed monitoring of the temperature curves is also possible at the mounting structure. Due to the furnace design, its location and the strict routines in handling, very high purity levels are achieved in comparison to similar setups and hence provide a mighty tool for SRF cavity R&D at DESY.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 485
EP  - 489
KW  - cavity
KW  - vacuum
KW  - controls
KW  - niobium
KW  - target
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-TUPTB037
UR  - https://jacow.org/srf2023/papers/tuptb037.pdf
ER  - 

TY  - CONF
AU  - Wolff, J.C.
AU  - Eschke, J.
AU  - Gössel, A.
AU  - Hillert, W.
AU  - Kasprzak, K.
AU  - Reschke, D.
AU  - Steder, L.
AU  - Trelle, L.
AU  - Wiencek, M.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - Impact of Medium Temperature Heat Treatments on the Magnetic Flux Expulsion Behavior of 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  - Medium temperature (mid-T) heat treatments at 300 °C are used to enhance the intrinsic quality factor of superconducting radio frequency (SRF) cavities. Unfortunately, such treatments potentially increase the sensitivity to trapped magnetic flux and consequently the surface resistance of the cavity. For this reason, it is crucial to maximize the expulsion of magnetic flux during the cool down. The flux expulsion behavior is next to the heat treatment mainly determined by the geometry, the niobium grain size and the grain orientation. However, it is also affected by parameters of the cavity performance tests like the cool down velocity, the spatial temperature gradient along the cavity surface and the magnetic flux density during the transition of the critical temperature. To improve the flux expulsion behavior and hence the efficiency of future accelerator facilities, the impact of these adjustable parameters as well as the mid-T heat treatment on 1.3 GHz TESLA-Type single-cell cavities is investigated by a new approach of a magnetometric mapping system. In this contribution first performance test results of cavities before- and after mid-T heat treatment are presented.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 731
EP  - 735
KW  - cavity
KW  - SRF
KW  - controls
KW  - niobium
KW  - experiment
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-WEPWB065
UR  - https://jacow.org/srf2023/papers/wepwb065.pdf
ER  - 

TY  - CONF
AU  - Kasprzak, K.
AU  - Buettner, Th.
AU  - Gössel, A.
AU  - Klinke, D.
AU  - Kostin, D.
AU  - Müller, C.
AU  - Vogel, E.
AU  - Wiencek, M.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - Test-Stand for Conditioning of Fundamental Power Couplers at DESY
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  - During the construction of the European-XFEL, activities related to Fundamental Power Couplers (FPCs) were outsourced to external partners and the former FPC test-stand area at DESY was given up due to infrastructure rearrangements. For the study of various XFEL upgrade scenarios a new test-stand for conditioning of FPCs at DESY is required. It will be used for evaluation of new coupler preparation methods with particular emphasis on Continuous Wave (CW) and long RF pulse operation. The new test-stand has been recently commissioned. Four FPCs have been prepared and tested. RF pulses were applied to the couplers, starting with the shortest possible pulse and increasing it’s power until maximum power was reached. The process was repeated with several pulse lengths until the maximum RF pulse length was reached. A review of the commissioning and first operation experience of the RF system are presented here.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 797
EP  - 800
KW  - FEL
KW  - vacuum
KW  - GUI
KW  - cavity
KW  - MMI
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-WEPWB092
UR  - https://jacow.org/srf2023/papers/wepwb092.pdf
ER  - 

TY  - CONF
AU  - Wenskat, M.
AU  - Bate, C.
AU  - Ghanbari, R.
AU  - Hillert, W.
AU  - Martens, C.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - A New Ultra-High Vacuum Furnace for SRF R&D
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 new vacuum furnace has been designed and purchased by the University of Hamburg and is operating in an ISO5 cleanroom. This furnace can anneal single-cell TESLA cavities at temperatures up to 1000°C and with a pressure of less than 10-7mbar or in a nitrogen atmosphere of up to 10-2mbar. We will lay out the underlying design ideas, based on the gained experience from our previous annealing research, and present the commissioning of the furnace itself. Additionally, we will show for the first time the results of sample and cavity tests after annealing in the furnace. This will be accompanied by an overview of the intended R&D process and scientific questions to be addressed.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 855
EP  - 858
KW  - cavity
KW  - vacuum
KW  - niobium
KW  - operation
KW  - SRF
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-WEPWB111
UR  - https://jacow.org/srf2023/papers/wepwb111.pdf
ER  - 

TY  - CONF
AU  - Monroy-Villa, R.
AU  - Gössel, A.
AU  - Hillert, W.
AU  - Martens, C.
AU  - Reschke, D.
AU  - Röhling, M.
AU  - Schmökel, M.
AU  - Thie, J.H.
AU  - Wenskat, M.
AU  - Wiencek, M.
ED  - Saito, Kenji
ED  - Xu, Ting
ED  - Sakamoto, Naruhiko
ED  - Schaa, Volker R.W.
ED  - Thomas, Paul W.
TI  - Commissioning of the UHH Quadrupole Resonator at DESY
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  - Pushing the limits of the accelerating field or quality factor of SRF cavities beyond pure Nb requires the implementation of specific inner surface treatments, which are yet to be studied and optimized. One of the fundamental challenges in exploring alternative materials is that only samples or cavity cuts can be fully characterized from a material point of view. On the other hand, complete cavities allow for the SRF characterization of the inner surface, while samples can usually only be analyzed using DC methods. To address this problem, a test resonator for samples, called "Quadrupole Resonator", was designed and operated at CERN and later at HZB. It allows for a full RF characterization of samples at frequencies of 0.42 GHz, 0.86 GHz, and 1.3 GHz, within a temperature range of 2-20 K and at magnetic fields up to 120 mT. This work presents the design process, which incorporated improvements motivated by mechanical and RF studies and experience, and the results from both warm and cold commissioning are discussed. More important, the results for the RF tests of a Nb sample after undergoing a series of heat treatments and an outlook of the further usage of the QPR is presented.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 952
EP  - 959
KW  - cavity
KW  - quadrupole
KW  - SRF
KW  - dipole
KW  - operation
DA  - 2023/09
PY  - 2023
SN  - 2673-5504
SN  - 978-3-95450-234-9
DO  - doi:10.18429/JACoW-SRF2023-THCAA02
UR  - https://jacow.org/srf2023/papers/thcaa02.pdf
ER  -