SRF2023 - List of Keywords (FEL)

Paper	Title	Other Keywords	Page
MOIXA06	Operational Experience with the European XFEL SRF Linac	operation, cavity, linac, LLRF	43
	Ch. Schmidt, M. Bousonville, J. Branlard, M. Diomede, S. Göller, D. Kostin, M. Scholz, V. Vogel (Fogel), N. Walker DESY, Hamburg, Germany
	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.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA06
About •	Received ※ 19 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 06 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB003	Flux Expulsion Lens: Concept and Measurements	cavity, niobium, site, SRF	56
	D.A. Turner European Organization for Nuclear Research (CERN), Geneva, Switzerland A. Gallifa Terricabras, T. Koettig, A. Macpherson, G.J. Rosaz, N. Stapley CERN, Meyrin, Switzerland I. González Díaz-Palacio University of Hamburg, Hamburg, Germany W. Hillert University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany M. Wenskat DESY, Hamburg, Germany
	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.
	Poster MOPMB003 [2.459 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB003
About •	Received ※ 27 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 14 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB058	Summary of the Superconducting Rf Measurements in AMTF Hall at DESY	cavity, SRF, cryomodule, superconductivity	248
	M. Wiencek, K. Kasprzak, D. Kostin, D. Reschke, L. Steder DESY, Hamburg, Germany
	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.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB058
About •	Received ※ 16 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 02 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB080	Dedicate SRF Cryomodule Test Facilities for S3FEL	cryomodule, electron, linac, SRF	298
	H. Li, C.F. He Institute of Advanced Science Facilities, Shenzhen, People’s Republic of China X.L. Wang, W.M. Yue, W.Q. Zhang IASF, Shenzhen, Guangdong, People’s Republic of China
	Shenzhen Superconducting Soft-X-Ray Free Electron Laser (S3FEL) has been proposed to build a continuous wave (CW) superconducting linear accelerator and produce FEL in the soft X-ray wavelength region. The proposed S3FEL LINAC consists of twenty-eight SRF cryomodules to accelerate beam energy up to 2.5 GeV. Prior to the cryomodules installed in the tunnel, SRF cavities and cryomodules will be conditioned and tested at a delicate SRF Cryomodule Test Facility (SMTF).The SMTF for S3FEL is currently under design which equipped with two vertical cryostats and three horizontal test benches. R&D work for the SMTF and its corresponding cryomodule assembly procedure is now on going. This paper describes the full set of layout design and implementation of the SMTF for S3FEL project as well as its latest status.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB080
About •	Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 07 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB082	SRF Accelerating Modules Upgrade for Flash Linac at DESY	cavity, SRF, linac, radiation	306
	D. Kostin, S. Barbanotti, J. Eschke, K. Jensch, N. Krupka, A. Muhs, D. Reschke, S. Saegebarth, J. Schaffran, P. Schilling, M. Schmökel, L. Steder, N. Steinhau-Kühl, A. Sulimov, E. Vogel, H. Weise, M. Wiencek, B. van der Horst DESY, Hamburg, Germany
	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].
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB082
About •	Received ※ 16 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 27 June 2023
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TUIAA01	Twenty Years of Cryogenic Operation of the Flash Superconducting Linac	cryomodule, linac, cavity, operation	347
	S. Barbanotti, DESY. Abassi, Y. Bozhko, K. Honkavaara, K. Jensch, D. Kostin, S. Lederer, T. Schnautz, S. Schreiber, A. Wagner, H. Weise DESY, Hamburg, Germany J. Roßbach University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany J. Zajac Linde Kryotechnik AG, Büro DESY Hamburg, Hamburg, Germany
	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.
	Slides TUIAA01 [6.861 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUIAA01
About •	Received ※ 16 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 20 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUIAA02	The FLASH 2020+ Upgrade Project	laser, electron, undulator, operation	354
	M. Vogt, E. Ferrari, C. Gerth, K. Honkavaara, J. Rönsch-Schulenburg, L. Schaper, S. Schreiber, J. Zemella DESY, Hamburg, Germany
	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.
	Slides TUIAA02 [15.921 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUIAA02
About •	Received ※ 21 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 07 July 2023
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WEPWB044	Realization of Accelerating Gradient Larger than 25 MV/m on High-Q 1.3 GHz 9-Cell Cavities for SHINE	cavity, accelerating-gradient, SRF, experiment	658
	Y. Zong, Q.X. Chen, X. Huang, Z. Wang SINAP, Shanghai, People’s Republic of China J.F. Chen, P.C. Dong, H.T. Hou, X.Y. Pu, J. Shi, S. Sun, D. Wang, J.N. Wu, S. Xing, S.J. Zhao, Y.L. Zhao SARI-CAS, Pudong, Shanghai, People’s Republic of China Y.W. Huang ShanghaiTech University, Shanghai, People’s Republic of China X.W. Wu Zhangjiang Lab, Shanghai, People’s Republic of China
	Funding: This work was supported by Shanghai Municipal Science and Technology Major Project (No. 2017SHZDZX02). We present our studies on the optimized nitrogen-doping and medium-temperature baking recipes applied on 1.3GHz SRF cavities, aiming at meeting the requirements of the SHINE project. The optimized nitrogen-doping process resulted in achieving a Q₀ of over 4.0×10¹⁰ at medium field and a maximum accelerating gradient exceeding 35 MV/m on single cell cavities, and a Q₀ of over 2.8×10¹⁰ at medium field and a maximum accelerating gradient exceeding 26 MV/m in 9-cell cavities. For 1.3 GHz 9-cell cavities subjected to medium-temperature baking, Q₀ values exceeding 3.5×10¹⁰ at 16 MV/m and maximum accelerating gradients surpassing 25 MV/m were achieved. These studies provide two options of high-Q recipes for SHINE cavities. The treatment processes of cavities and their vertical test results are described in this paper. *chenjinfang@sari.ac.cn
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB044
About •	Received ※ 19 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 26 June 2023
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WEPWB092	Test-Stand for Conditioning of Fundamental Power Couplers at DESY	vacuum, GUI, cavity, MMI	797
	K. Kasprzak, Th. Buettner, A. Gössel, D. Klinke, D. Kostin, C. Müller, E. Vogel, M. Wiencek DESY, Hamburg, Germany
	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.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB092
About •	Received ※ 15 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 16 July 2023
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WEPWB102	Recent Progress of Fundamental Power Couplers for the SHINE Project	vacuum, cryomodule, cavity, electron	827
	Z.Y. Ma, J.F. Chen, H.T. Hou, B. Liu, Y. Liu, S. Sun, D. Wang, L. Yin, M. Zhang, S.J. Zhao, Y.B. Zhao, Z.T. Zhao, X. Zheng SARI-CAS, Pudong, Shanghai, People’s Republic of China
	Funding: Project supported by Shanghai Municipal Science and Technology Major Project (Grant No.2017SHZDZX02). The superconducting radio-frequency electron linear accelerator of the Shanghai HIgh repetition rate XFEL aNd Extreme light facility (SHINE) contains 610 1.3 GHz fundamental power couplers which are assembled in 77 superconducting cryomodules used for beam acceleration, and 16 3.9 GHz fundamental power couplers, which are assembled in two third harmonic superconducting cryomodules used for linearizing the longitudinal phase space. The first batch of 26 1.3 GHz coupler prototypes and two 3.9 GHz coupler prototypes have been fabricated from three domestic manufacturers for basic research. Several key manufacturing processes have been developed and qualified, including high residual resistivity ratio (RRR) copper plating, vacuum brazing of ceramic windows, electron beam welding and titanium nitride coating. All the 1.3 GHz coupler prototypes have been power conditioned with 14 kW travelling wave (TW) and 7 kW standing wave (SW) RF in continuous-wave (CW) mode. Even higher power levels have been demonstrated with 20 kW TW and 10 kW SW RF, which indicates their robustness. Both 3.9 GHz coupler prototypes have been power conditioned with 2.2 kW TW and 2 kW SW RF in CW mode.
	Poster WEPWB102 [2.361 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB102
About •	Received ※ 16 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 05 July 2023
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WEPWB104	RF Conditioning of MYRRHA Couplers at IJCLab	vacuum, electron, cavity, multipactoring	835
	N. ElKamchi, S. Berthelot, P. Duchesne, C. Joly, W. Kaabi, C. Magueur Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France Y. Gómez Martínez LPSC, Grenoble Cedex, France C. Lhomme IJCLab, ORSAY, France
	Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA) is an experimental accelerator-driven system in development at SCK•CEN. It will allow fuel developments, material developments for GEN IV systems, material developments for fusion reactors and radioisotope production for medical and industrial applications1. The IJCLab has in charge the industrial monitoring, the quality control and the RF conditioning of the power couplers up to 80KW at 352Mhz. This paper presents the conditioning bench adapted from the successful experience of IJCLab in the conditioning of the XFEL couplers2. The results of the conditioning of prototype couplers are described and discussed. 1. Abderrahim, P. MYRRHA a multi-purpose hybrid research reactor for high-tech applications. United States: N. p., 2012. Web 2. H. Guler, Proceedings of IPAC2016, Busan, Korea
	Poster WEPWB104 [0.875 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB104
About •	Received ※ 26 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 08 August 2023
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WEPWB135	A Novel Twin Drive Tuner Mechanism for 1.3 GHz ILC Cavity	cavity, SRF, operation, site	914
	M. Yamanaka KEK, Ibaraki, Japan
	A tuner is a device that adjusts the resonant frequency of a cavity. Here we propose a new tuner mechanism for the 1.3 GHz ILC cavity. A bellow is provided in the central portion of the helium tank in the longitudinal direction, and flanges are provided on both sides of the bellows. A linear motion actuator is fixed to the flange on one side, and the frequency is changed by pushing and pulling the flange on the opposite side. Significantly, two linear motion actuators are placed in circumference and working simultaneously. It is named a twin-drive tuner. According to the ILC specification, the cavity has a spring constant of 3 KN/mm, requiring a stroke of 2 mm to adjust the 600 kHz range. A loading force of 6 kN is required. This is shared by two linear motion actuators. We developed a prototype actuator with a loading force of 4 kN per unit. It consists of a stepping motor and a sliding screw with a plastic nut. An experimental device was constructed using this actuator and a 1.3 GHz cavity with a helium tank, and the frequency tuning was evaluated. The displacement between the flanges and the frequency are proportional, both have good linearity, and the slope is 296 kHz/mm.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB135
About •	Received ※ 17 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 17 July 2023
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THIAA01	Development of 3.9 GHz 9-Cell Cavities at SHINE	cavity, electron, linac, laser	921
	X.W. Wu Zhangjiang Lab, Shanghai, People’s Republic of China J.F. Chen, P.C. Dong, Y.F. Liu, X.H. Ouyang, S. Sun, J.N. Wu, S. Xing, Y.X. Zhang, S.J. Zhao, Y.L. Zhao SARI-CAS, Pudong, Shanghai, People’s Republic of China X. Huang, Z. Wang, Y. Zong SINAP, Shanghai, People’s Republic of China Y.W. Huang, R.Z. Xia ShanghaiTech University, Shanghai, People’s Republic of China
	The Shanghai high-repetition-rate XFEL and extreme light facility (SHINE) Linac requires two 3.9~GHz crymodules to linearize energy distribution before the bunch compressor. As a key component to the project, studies of 3.9~GHz cavities were conducted in the past few years. The first 3.9~GHz 9-cell prototype cavity has been fabricated, tested, and qualified. It reached Q₀=3.5×10⁹ at 13.1~MV/m and a maximum accelerating gradient of 25.0~MV/m during the vertical test of the bare cavity. The prototype has been helium tank integrated and reached Q₀=2.9×10⁹ at 13.1~MV/m in the vertical test, with a large margin with respect to the SHINE specification. The second prototype has been fabricated and is planned to be tested in 2023. This paper will cover the fabrication, surface treatment, and RF test of the 3.9~GHz cavities.
	Slides THIAA01 [7.573 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-THIAA01
About •	Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 18 July 2023
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Paper

Title

Other Keywords

Page

MOIXA06

Operational Experience with the European XFEL SRF Linac

operation, cavity, linac, LLRF

43

Ch. Schmidt, M. Bousonville, J. Branlard, M. Diomede, S. Göller, D. Kostin, M. Scholz, V. Vogel (Fogel), N. Walker
DESY, Hamburg, Germany

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.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA06

About •

Received ※ 19 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 06 July 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB003

Flux Expulsion Lens: Concept and Measurements

cavity, niobium, site, SRF

56

D.A. Turner
European Organization for Nuclear Research (CERN), Geneva, Switzerland
A. Gallifa Terricabras, T. Koettig, A. Macpherson, G.J. Rosaz, N. Stapley
CERN, Meyrin, Switzerland
I. González Díaz-Palacio
University of Hamburg, Hamburg, Germany
W. Hillert
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
M. Wenskat
DESY, Hamburg, Germany

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.

Poster MOPMB003 [2.459 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB003

About •

Received ※ 27 June 2023 — Revised ※ 28 June 2023 — Accepted ※ 30 June 2023 — Issue date ※ 14 July 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB058

Summary of the Superconducting Rf Measurements in AMTF Hall at DESY

cavity, SRF, cryomodule, superconductivity

248

M. Wiencek, K. Kasprzak, D. Kostin, D. Reschke, L. Steder
DESY, Hamburg, Germany

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.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB058

About •

Received ※ 16 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 02 July 2023

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MOPMB080

Dedicate SRF Cryomodule Test Facilities for S3FEL

cryomodule, electron, linac, SRF

298

H. Li, C.F. He
Institute of Advanced Science Facilities, Shenzhen, People’s Republic of China
X.L. Wang, W.M. Yue, W.Q. Zhang
IASF, Shenzhen, Guangdong, People’s Republic of China

Shenzhen Superconducting Soft-X-Ray Free Electron Laser (S3FEL) has been proposed to build a continuous wave (CW) superconducting linear accelerator and produce FEL in the soft X-ray wavelength region. The proposed S3FEL LINAC consists of twenty-eight SRF cryomodules to accelerate beam energy up to 2.5 GeV. Prior to the cryomodules installed in the tunnel, SRF cavities and cryomodules will be conditioned and tested at a delicate SRF Cryomodule Test Facility (SMTF).The SMTF for S3FEL is currently under design which equipped with two vertical cryostats and three horizontal test benches. R&D work for the SMTF and its corresponding cryomodule assembly procedure is now on going. This paper describes the full set of layout design and implementation of the SMTF for S3FEL project as well as its latest status.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB080

About •

Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 07 July 2023

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB082

SRF Accelerating Modules Upgrade for Flash Linac at DESY

cavity, SRF, linac, radiation

306

D. Kostin, S. Barbanotti, J. Eschke, K. Jensch, N. Krupka, A. Muhs, D. Reschke, S. Saegebarth, J. Schaffran, P. Schilling, M. Schmökel, L. Steder, N. Steinhau-Kühl, A. Sulimov, E. Vogel, H. Weise, M. Wiencek, B. van der Horst
DESY, Hamburg, Germany

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].

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB082

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Received ※ 16 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 27 June 2023

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUIAA01

Twenty Years of Cryogenic Operation of the Flash Superconducting Linac

cryomodule, linac, cavity, operation

347

S. Barbanotti, DESY. Abassi, Y. Bozhko, K. Honkavaara, K. Jensch, D. Kostin, S. Lederer, T. Schnautz, S. Schreiber, A. Wagner, H. Weise
DESY, Hamburg, Germany
J. Roßbach
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
J. Zajac
Linde Kryotechnik AG, Büro DESY Hamburg, Hamburg, Germany

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.

Slides TUIAA01 [6.861 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUIAA01

About •

Received ※ 16 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 20 July 2023

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TUIAA02

The FLASH 2020+ Upgrade Project

laser, electron, undulator, operation

354

M. Vogt, E. Ferrari, C. Gerth, K. Honkavaara, J. Rönsch-Schulenburg, L. Schaper, S. Schreiber, J. Zemella
DESY, Hamburg, Germany

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.

Slides TUIAA02 [15.921 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUIAA02

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Received ※ 21 June 2023 — Revised ※ 23 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 07 July 2023

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WEPWB044

Realization of Accelerating Gradient Larger than 25 MV/m on High-Q 1.3 GHz 9-Cell Cavities for SHINE

cavity, accelerating-gradient, SRF, experiment

658

Y. Zong, Q.X. Chen, X. Huang, Z. Wang
SINAP, Shanghai, People’s Republic of China
J.F. Chen, P.C. Dong, H.T. Hou, X.Y. Pu, J. Shi, S. Sun, D. Wang, J.N. Wu, S. Xing, S.J. Zhao, Y.L. Zhao
SARI-CAS, Pudong, Shanghai, People’s Republic of China
Y.W. Huang
ShanghaiTech University, Shanghai, People’s Republic of China
X.W. Wu
Zhangjiang Lab, Shanghai, People’s Republic of China

Funding: This work was supported by Shanghai Municipal Science and Technology Major Project (No. 2017SHZDZX02).
We present our studies on the optimized nitrogen-doping and medium-temperature baking recipes applied on 1.3GHz SRF cavities, aiming at meeting the requirements of the SHINE project. The optimized nitrogen-doping process resulted in achieving a Q₀ of over 4.0×10¹⁰ at medium field and a maximum accelerating gradient exceeding 35 MV/m on single cell cavities, and a Q₀ of over 2.8×10¹⁰ at medium field and a maximum accelerating gradient exceeding 26 MV/m in 9-cell cavities. For 1.3 GHz 9-cell cavities subjected to medium-temperature baking, Q₀ values exceeding 3.5×10¹⁰ at 16 MV/m and maximum accelerating gradients surpassing 25 MV/m were achieved. These studies provide two options of high-Q recipes for SHINE cavities. The treatment processes of cavities and their vertical test results are described in this paper.
*chenjinfang@sari.ac.cn

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB044

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Received ※ 19 June 2023 — Revised ※ 22 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 26 June 2023

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WEPWB092

Test-Stand for Conditioning of Fundamental Power Couplers at DESY

vacuum, GUI, cavity, MMI

797

K. Kasprzak, Th. Buettner, A. Gössel, D. Klinke, D. Kostin, C. Müller, E. Vogel, M. Wiencek
DESY, Hamburg, Germany

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.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB092

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Received ※ 15 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 16 July 2023

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WEPWB102

Recent Progress of Fundamental Power Couplers for the SHINE Project

vacuum, cryomodule, cavity, electron

827

Z.Y. Ma, J.F. Chen, H.T. Hou, B. Liu, Y. Liu, S. Sun, D. Wang, L. Yin, M. Zhang, S.J. Zhao, Y.B. Zhao, Z.T. Zhao, X. Zheng
SARI-CAS, Pudong, Shanghai, People’s Republic of China

Funding: Project supported by Shanghai Municipal Science and Technology Major Project (Grant No.2017SHZDZX02).
The superconducting radio-frequency electron linear accelerator of the Shanghai HIgh repetition rate XFEL aNd Extreme light facility (SHINE) contains 610 1.3 GHz fundamental power couplers which are assembled in 77 superconducting cryomodules used for beam acceleration, and 16 3.9 GHz fundamental power couplers, which are assembled in two third harmonic superconducting cryomodules used for linearizing the longitudinal phase space. The first batch of 26 1.3 GHz coupler prototypes and two 3.9 GHz coupler prototypes have been fabricated from three domestic manufacturers for basic research. Several key manufacturing processes have been developed and qualified, including high residual resistivity ratio (RRR) copper plating, vacuum brazing of ceramic windows, electron beam welding and titanium nitride coating. All the 1.3 GHz coupler prototypes have been power conditioned with 14 kW travelling wave (TW) and 7 kW standing wave (SW) RF in continuous-wave (CW) mode. Even higher power levels have been demonstrated with 20 kW TW and 10 kW SW RF, which indicates their robustness. Both 3.9 GHz coupler prototypes have been power conditioned with 2.2 kW TW and 2 kW SW RF in CW mode.

Poster WEPWB102 [2.361 MB]

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reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB102

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Received ※ 16 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 05 July 2023

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WEPWB104

RF Conditioning of MYRRHA Couplers at IJCLab

vacuum, electron, cavity, multipactoring

835

N. ElKamchi, S. Berthelot, P. Duchesne, C. Joly, W. Kaabi, C. Magueur
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
Y. Gómez Martínez
LPSC, Grenoble Cedex, France
C. Lhomme
IJCLab, ORSAY, France

Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA) is an experimental accelerator-driven system in development at SCK•CEN. It will allow fuel developments, material developments for GEN IV systems, material developments for fusion reactors and radioisotope production for medical and industrial applications1. The IJCLab has in charge the industrial monitoring, the quality control and the RF conditioning of the power couplers up to 80KW at 352Mhz. This paper presents the conditioning bench adapted from the successful experience of IJCLab in the conditioning of the XFEL couplers2. The results of the conditioning of prototype couplers are described and discussed.
1. Abderrahim, P. MYRRHA a multi-purpose hybrid research reactor for high-tech applications. United States: N. p., 2012. Web
2. H. Guler, Proceedings of IPAC2016, Busan, Korea

Poster WEPWB104 [0.875 MB]

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reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB104

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Received ※ 26 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 08 August 2023

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WEPWB135

A Novel Twin Drive Tuner Mechanism for 1.3 GHz ILC Cavity

cavity, SRF, operation, site

914

M. Yamanaka
KEK, Ibaraki, Japan

A tuner is a device that adjusts the resonant frequency of a cavity. Here we propose a new tuner mechanism for the 1.3 GHz ILC cavity. A bellow is provided in the central portion of the helium tank in the longitudinal direction, and flanges are provided on both sides of the bellows. A linear motion actuator is fixed to the flange on one side, and the frequency is changed by pushing and pulling the flange on the opposite side. Significantly, two linear motion actuators are placed in circumference and working simultaneously. It is named a twin-drive tuner. According to the ILC specification, the cavity has a spring constant of 3 KN/mm, requiring a stroke of 2 mm to adjust the 600 kHz range. A loading force of 6 kN is required. This is shared by two linear motion actuators. We developed a prototype actuator with a loading force of 4 kN per unit. It consists of a stepping motor and a sliding screw with a plastic nut. An experimental device was constructed using this actuator and a 1.3 GHz cavity with a helium tank, and the frequency tuning was evaluated. The displacement between the flanges and the frequency are proportional, both have good linearity, and the slope is 296 kHz/mm.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB135

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Received ※ 17 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 17 July 2023

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THIAA01

Development of 3.9 GHz 9-Cell Cavities at SHINE

cavity, electron, linac, laser

921

X.W. Wu
Zhangjiang Lab, Shanghai, People’s Republic of China
J.F. Chen, P.C. Dong, Y.F. Liu, X.H. Ouyang, S. Sun, J.N. Wu, S. Xing, Y.X. Zhang, S.J. Zhao, Y.L. Zhao
SARI-CAS, Pudong, Shanghai, People’s Republic of China
X. Huang, Z. Wang, Y. Zong
SINAP, Shanghai, People’s Republic of China
Y.W. Huang, R.Z. Xia
ShanghaiTech University, Shanghai, People’s Republic of China

The Shanghai high-repetition-rate XFEL and extreme light facility (SHINE) Linac requires two 3.9~GHz crymodules to linearize energy distribution before the bunch compressor. As a key component to the project, studies of 3.9~GHz cavities were conducted in the past few years. The first 3.9~GHz 9-cell prototype cavity has been fabricated, tested, and qualified. It reached Q₀=3.5×10⁹ at 13.1~MV/m and a maximum accelerating gradient of 25.0~MV/m during the vertical test of the bare cavity. The prototype has been helium tank integrated and reached Q₀=2.9×10⁹ at 13.1~MV/m in the vertical test, with a large margin with respect to the SHINE specification. The second prototype has been fabricated and is planned to be tested in 2023. This paper will cover the fabrication, surface treatment, and RF test of the 3.9~GHz cavities.

Slides THIAA01 [7.573 MB]

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reference for this paper ※ doi:10.18429/JACoW-SRF2023-THIAA01

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Received ※ 19 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 18 July 2023

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