SRF2019 - List of Keywords (radiation)

Paper	Title	Other Keywords	Page
MOP035	Cryogenic Infrastructure at BESSY II – Current Installations and Future Developments	cryogenics, cavity, storage-ring, gun	131
	S. Heling, W. Anders, J. Heinrich, A. Hellwig, K. Janke, S. Rotterdam HZB, Berlin, Germany
	In Berlin-Adlershof the Helmholtz-Zentrum Berlin (HZB) is operating the synchrotron radiation source BESSY II. Two superconducting wave-length shifter magnets are built-in the storage ring of BESSY II which are cooled with liquid helium. Additionally several test facilities for superconducting cavities are operated at HZB needing helium at 1.8 K. The required helium is supplied by two helium liquefiers. Parallel to operation of the existing facilities the BERLinPro project will qualify as test facility for ERL science and technology. In order to guarantee the required supply with helium at different temperature levels one of the existing helium liquefiers has been relocated to the new accelerator building and the existing cryogenic infrastructure has been upgraded with a new 10 000 L dewar, three valve boxes, a cold compressor box, warm pumps and a 80 K helium system. This paper specifies the setup of the above described helium cryoplants in detail and gives insight into the challenges of development. The paper concludes with an outlook of the upcoming developments of the cryogenic infrastructure at HZB.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP035
About •	paper received ※ 20 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP047	Progress of IFMIF/EVEDA Project and Prospects for A-FNS	neutron, rfq, SRF, cavity	159
	S. Ishida, A. Kasugai, K. Sakamoto QST, Aomori, Japan P. Cara IFMIF/EVEDA, Rokkasho, Japan H. Dzitko F4E, Germany
	International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based D-Li neutron source, in which two 40 MeV Deuteron(D) beams with a total current 250 mA impact on a liquid Li stream flowing at 15 m/s. In the IFMIF/EVEDA project under the Broader Approach (BA) agreement, the Li target was continuously operated with the cold trap and satisfied the stability requirement throughout the continuous operation. The Linear IFMIF Prototype Accelerator (LIPAc) is currently under development in Rokkasho, Japan, to demonstrate the 9 MeV/125 mA D⁺ beam acceleration. Recently, the first proton beam was injected into the RFQ with more than 90 % of transmission, followed by the first D⁺ beam accelerated at 5 MeV. The SRF linac necessary for the 9-MeV D⁺ beam is nearing completion of the manufacturing phase and will be assembled in Rokkasho. Based on these results, a conceptual design of the Advanced Fusion Neutron Source (A-FNS) for its construction in Rokkasho is underway to obtain material irradiation data for a DEMO reactor. The A-FNS is designed to be composed of an accelerator facility with a 40 MeV/125 mA D⁺ beam, a test facility including a liquid Li target system and a post irradiation examination facility, and to enable multipurpose utilization for neutron application.
	Poster MOP047 [2.327 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP047
About •	paper received ※ 29 June 2019 paper accepted ※ 12 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP051	3.9 GHz SRF Production Cavities for LCLS-II	cavity, cryomodule, linac, vacuum	173
	S. Aderhold, A. Burrill SLAC, Menlo Park, California, USA D.J. Bice, C.M. Ginsburg, C.J. Grimm, T.N. Khabiboulline, O.S. Melnychuk, D.A. Sergatskov, N. Solyak, G. Wu Fermilab, Batavia, Illinois, USA
	Funding: This work was supported by the US DOE and the LCLS-II Project. The main part of the SRF linac for the Linac Coherent Light Source II (LCLS-II) at SLAC will consist of 35 cryomodules with superconducting RF cavities operating at 1.3 GHz. In addition, two cryomodules with 3.9 GHz cavities will be installed and help to linearize the longitudinal phase space of the beam. During the design verification phase, four prototype 9-cell 3.9 GHz cavities had been built by industry and then processed, including chemical surface removal and heat treatment, and tested at Fermi National Accelerator Laboratory. Based on the resulting cavity treatment recipe, 24 cavities (for two cryomodules to be installed in the linac and one spare cryomodule) have been built by industry and tested at Fermilab prior to cryomodule string assembly. We present an overview of the cavity production and the results of the vertical acceptance tests for the LCLS-II 3.9 GHz cavities.
	Poster MOP051 [1.015 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP051
About •	paper received ※ 02 July 2019 paper accepted ※ 03 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP041	SRF testing for Mainz Energy Recovering Superconducting Accelerator MESA	cavity, cryomodule, SRF, controls	508
	T. Stengler, K. Aulenbacher, F. Hug, S.D.W. Thomas KPH, Mainz, Germany K. Aulenbacher GSI, Darmstadt, Germany K. Aulenbacher HIM, Mainz, Germany
	Funding: This work is supported by the German Research Foundation (DFG) under the Cluster of Excellence "PRISMA+" EXC 2118/2019 The two superconducting radio frequency acceleration cryomodules for the new multiturn ERL ’Mainz Energy Recovering Superconducting Accelerator’ MESA at Johannes Gutenberg-Universität Mainz have been fabricated and are currently under testing at the Helmholtz Institut Mainz. These modules are based on the ELBE modules of the Helmholtz Center Dresden-Rossendorf but are modified to suit the high current and energy-recovering operation at MESA. The energy gain per module per turn should be 25 MeV, provided by two TESLA cavities, which were vertically tested at DESY, Hamburg, Germany. These tests showed an excellent performance of the quench limit and quality factor for three out of the four cavities. The fourth cavity has a lower but still acceptable quench limit and quality factor. In order to validate the performance of the fully assembled cryomodules after delivery to Mainz a test stand has been set up at the Helmholtz Institut Mainz. The test stand is described in detail and the status of the module testing is reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP041
About •	paper received ※ 21 June 2019 paper accepted ※ 29 June 2019 issue date ※ 14 August 2019
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THP032	SRF Gun and SRF Linac Driven THz at ELBE Successfully in User Operation	gun, SRF, electron, linac	915
	R. Xiang, A. Arnold, P.E. Evtushenko, S. Kovalev, U. Lehnert, P.N. Lu, S. Ma, P. Michel, P. Murcek, A.A. Ryzhov, J. Schaber, Ch. Schneider, J. Teichert HZDR, Dresden, Germany H. Vennekate RI Research Instruments GmbH, Bergisch Gladbach, Germany I. Will MBI, Berlin, Germany
	Funding: The work was partly supported by the German Federal Ministry of Education and Research (BMBF) grant 05K12CR1 and Deutsche Forschungsgemeinschaft (DFG) project (XI 10⁶/2-1). The first all-SRF accelerator driven THz source has been operated as a user facility since 2018 at ELBE radiation center. The CW electron beam is extracted from SRF gun II, accelerated to relativistic energies and compressed to sub-ps length in the ELBE SRF linac with a chicane. THz pulses are produced by pass-ing the short electron bunches through a diffraction radiator (CDR) and an undulator. The coherent THz power increases quadratically with bunch charge. The pulse energy up to 10 µJ at 0.3 THz with 100 kHz has been generated.
	Poster THP032 [1.207 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP032
About •	paper received ※ 02 July 2019 paper accepted ※ 04 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP041	Impact of the Cu Substrate Surface Preparation on the Morphological, Superconductive and RF Properties of the Nb Superconductive Coatings	laser, cavity, SRF, niobium	935
	C. Pira, E. Chyhyrynets INFN/LNL, Legnaro (PD), Italy C.Z. Antoine CEA-IRFU, Gif-sur-Yvette, France X. Jiang, S.B. Leith, M. Vogel University Siegen, Siegen, Germany A. Katasevs, J. Kaupužs, A. Medvids, P. Onufrijevs Riga Technical University, Riga, Latvia O. Kugeler HZB, Berlin, Germany O.B. Malyshev, R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom R. Ries, E. Seiler Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic A. Sublet CERN, Meyrin, Switzerland
	Funding: This project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 730871. Nowadays, one of the main issues of the superconducting thin film resonant cavities is the Cu surface preparation. A better understanding of the impact of copper surface preparation on the morphological, superconductive (SC) and RF properties of the coating, is mandatory in order to improve the performances of superconducting cavities by coating techniques. ARIES H₂020 collaboration includes a specific work package (WP15) to study the influence of Cu surface polishing on the SRF performances of Nb coatings that involves a team of 8 research groups from 7 different countries. In the present work, a comparison of 4 different polishing processes for Cu (Tumbling, EP, SUBU, EP+SUBU) is presented through the evaluation of the SC and morphological properties of Nb thin film coated on Cu planar samples and QPR samples, polished with different procedures. Effects of laser annealing on Nb thin films have also been studied. Different surface characterizations have been applied: roughness measurements, SEM, EDS, XRD, AFM, and thermal and photo-stimulated exoelectrons measurements. SC properties were evaluated with PPMS, and QPR measurements will be carry out at HZB in the beginning of 2019.
	Poster THP041 [3.196 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP041
About •	paper received ※ 23 June 2019 paper accepted ※ 05 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP090	Characterization of SSR1 Cavities for PIP-II Linac	cavity, cryomodule, multipactoring, linac	1120
	A.I. Sukhanov, F.G. Garcia, B.M. Hanna, S. Kazakov, Y.M. Pischalnikov, O.V. Prokofiev, W. Schappert, I. Terechkine, V.P. Yakovlev, J.C. Yun Fermilab, Batavia, Illinois, USA C. Contreras-Martinez FRIB, East Lansing, Michigan, USA S. Samani Queen Mary University of London, London, United Kingdom
	A cryomodule of 325 MHz Single Spoke Resonator type 1 (SSR1) superconducting RF cavities is being built at Fermilab for the PIP-II project. Twelve SSR1 cavities were manufactured in industry in USA (10 cavities) and India (2 cavities) and delivered to Fermilab. In this paper we present results of characterization of fully integrated jacketed cavities with high power coupler and tuner at the Fermilab Spoke Test Cryostat (STC).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP090
About •	paper received ※ 23 June 2019 paper accepted ※ 01 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP093	Upgrade on the Experimental Activities for ESS at the LASA Vertical Test Facility	cavity, diagnostics, electron, detector	1133
	M. Bertucci, A. Bosotti, A. D’Ambros, P. Michelato, L. Monaco, C. Pagani, R. Paparella, D. Sertore INFN/LASA, Segrate (MI), Italy
	The LASA vertical test facility is equipped for the cold test of ESS medium-beta 704.42 MHz cavities, with and without He tank, and is integrated with several diagnostic tools allowing a careful analysis of cavity performance limitations. This paper reports the latest tests on ESS cavities - both prototypes and series - and a discussion on the experimental results. The recent instrumental upgrades implemented in the facility - and the ones foreseen for the future in view of a further improvement of cavity performances - are also pointed out.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP093
About •	paper received ※ 24 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP097	Field Emission Studies on ESS Elliptical Prototype Cavities at CEA Saclay	cavity, cryomodule, electron, detector	1147
	E. Cenni, M. Baudrier, G. Devanz, L. Maurice, O. Piquet, D. Roudier CEA-DRF-IRFU, France
	CEA Saclay is in charge of the cavity prototypes that is designing, manufacturing, testing and integrating them into demonstrator cryomodules. We have manufactured 6 medium beta and 5 high beta cavities. As part of these activities we are interested in field emission as one of the limiting factors for cavity performances. We are currently collecting data from cavities operated in vertical cryostat and inside cryomodules. Analysis are carried out by means of particle tracking simulation and comparison with radiation dose monitor and scintillators.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP097
About •	paper received ※ 27 June 2019 paper accepted ※ 01 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRCAB7	Plasma Processing to Reduce Field Emission in LCLS-II 1.3 GHz SRF Cavities	plasma, cavity, vacuum, HOM	1231
	B. Giaccone, J. Zasadzinski IIT, Chicago, Illinois, USA P. Berrutti, B. Giaccone, A. Grassellino, M. Martinello Fermilab, Batavia, Illinois, USA M. Doleans ORNL, Oak Ridge, Tennessee, USA D. Gonnella, G. Lanza, M.C. Ross SLAC, Menlo Park, California, USA
	Plasma cleaning for LCLS-II 9-cell 1.3 GHz cavities is under study at Fermilab. Starting from ORNL method, we have developed a new technique for plasma ignition using HOMs. Plasma processing is being applied to contaminated and field emitting cavities, here are discussed the first results in terms of Q and radiation vs E measured before and after treatment. Further studies are ongoing to optimize plasma parameters and to acquire statistics on plasma cleaning effectiveness.
	Slides FRCAB7 [14.701 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-FRCAB7
About •	paper received ※ 23 June 2019 paper accepted ※ 04 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOP035

Cryogenic Infrastructure at BESSY II – Current Installations and Future Developments

cryogenics, cavity, storage-ring, gun

131

S. Heling, W. Anders, J. Heinrich, A. Hellwig, K. Janke, S. Rotterdam
HZB, Berlin, Germany

In Berlin-Adlershof the Helmholtz-Zentrum Berlin (HZB) is operating the synchrotron radiation source BESSY II. Two superconducting wave-length shifter magnets are built-in the storage ring of BESSY II which are cooled with liquid helium. Additionally several test facilities for superconducting cavities are operated at HZB needing helium at 1.8 K. The required helium is supplied by two helium liquefiers. Parallel to operation of the existing facilities the BERLinPro project will qualify as test facility for ERL science and technology. In order to guarantee the required supply with helium at different temperature levels one of the existing helium liquefiers has been relocated to the new accelerator building and the existing cryogenic infrastructure has been upgraded with a new 10 000 L dewar, three valve boxes, a cold compressor box, warm pumps and a 80 K helium system. This paper specifies the setup of the above described helium cryoplants in detail and gives insight into the challenges of development. The paper concludes with an outlook of the upcoming developments of the cryogenic infrastructure at HZB.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP035

About •

paper received ※ 20 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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

MOP047

Progress of IFMIF/EVEDA Project and Prospects for A-FNS

neutron, rfq, SRF, cavity

159

S. Ishida, A. Kasugai, K. Sakamoto
QST, Aomori, Japan
P. Cara
IFMIF/EVEDA, Rokkasho, Japan
H. Dzitko
F4E, Germany

International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based D-Li neutron source, in which two 40 MeV Deuteron(D) beams with a total current 250 mA impact on a liquid Li stream flowing at 15 m/s. In the IFMIF/EVEDA project under the Broader Approach (BA) agreement, the Li target was continuously operated with the cold trap and satisfied the stability requirement throughout the continuous operation. The Linear IFMIF Prototype Accelerator (LIPAc) is currently under development in Rokkasho, Japan, to demonstrate the 9 MeV/125 mA D⁺ beam acceleration. Recently, the first proton beam was injected into the RFQ with more than 90 % of transmission, followed by the first D⁺ beam accelerated at 5 MeV. The SRF linac necessary for the 9-MeV D⁺ beam is nearing completion of the manufacturing phase and will be assembled in Rokkasho. Based on these results, a conceptual design of the Advanced Fusion Neutron Source (A-FNS) for its construction in Rokkasho is underway to obtain material irradiation data for a DEMO reactor. The A-FNS is designed to be composed of an accelerator facility with a 40 MeV/125 mA D⁺ beam, a test facility including a liquid Li target system and a post irradiation examination facility, and to enable multipurpose utilization for neutron application.

Poster MOP047 [2.327 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP047

About •

paper received ※ 29 June 2019 paper accepted ※ 12 July 2019 issue date ※ 14 August 2019

Export •

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

MOP051

3.9 GHz SRF Production Cavities for LCLS-II

cavity, cryomodule, linac, vacuum

173

S. Aderhold, A. Burrill
SLAC, Menlo Park, California, USA
D.J. Bice, C.M. Ginsburg, C.J. Grimm, T.N. Khabiboulline, O.S. Melnychuk, D.A. Sergatskov, N. Solyak, G. Wu
Fermilab, Batavia, Illinois, USA

Funding: This work was supported by the US DOE and the LCLS-II Project.
The main part of the SRF linac for the Linac Coherent Light Source II (LCLS-II) at SLAC will consist of 35 cryomodules with superconducting RF cavities operating at 1.3 GHz. In addition, two cryomodules with 3.9 GHz cavities will be installed and help to linearize the longitudinal phase space of the beam. During the design verification phase, four prototype 9-cell 3.9 GHz cavities had been built by industry and then processed, including chemical surface removal and heat treatment, and tested at Fermi National Accelerator Laboratory. Based on the resulting cavity treatment recipe, 24 cavities (for two cryomodules to be installed in the linac and one spare cryomodule) have been built by industry and tested at Fermilab prior to cryomodule string assembly. We present an overview of the cavity production and the results of the vertical acceptance tests for the LCLS-II 3.9 GHz cavities.

Poster MOP051 [1.015 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP051

About •

paper received ※ 02 July 2019 paper accepted ※ 03 July 2019 issue date ※ 14 August 2019

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

TUP041

SRF testing for Mainz Energy Recovering Superconducting Accelerator MESA

cavity, cryomodule, SRF, controls

508

T. Stengler, K. Aulenbacher, F. Hug, S.D.W. Thomas
KPH, Mainz, Germany
K. Aulenbacher
GSI, Darmstadt, Germany
K. Aulenbacher
HIM, Mainz, Germany

Funding: This work is supported by the German Research Foundation (DFG) under the Cluster of Excellence "PRISMA+" EXC 2118/2019
The two superconducting radio frequency acceleration cryomodules for the new multiturn ERL ’Mainz Energy Recovering Superconducting Accelerator’ MESA at Johannes Gutenberg-Universität Mainz have been fabricated and are currently under testing at the Helmholtz Institut Mainz. These modules are based on the ELBE modules of the Helmholtz Center Dresden-Rossendorf but are modified to suit the high current and energy-recovering operation at MESA. The energy gain per module per turn should be 25 MeV, provided by two TESLA cavities, which were vertically tested at DESY, Hamburg, Germany. These tests showed an excellent performance of the quench limit and quality factor for three out of the four cavities. The fourth cavity has a lower but still acceptable quench limit and quality factor. In order to validate the performance of the fully assembled cryomodules after delivery to Mainz a test stand has been set up at the Helmholtz Institut Mainz. The test stand is described in detail and the status of the module testing is reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP041

About •

paper received ※ 21 June 2019 paper accepted ※ 29 June 2019 issue date ※ 14 August 2019

Export •

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

THP032

SRF Gun and SRF Linac Driven THz at ELBE Successfully in User Operation

gun, SRF, electron, linac

915

R. Xiang, A. Arnold, P.E. Evtushenko, S. Kovalev, U. Lehnert, P.N. Lu, S. Ma, P. Michel, P. Murcek, A.A. Ryzhov, J. Schaber, Ch. Schneider, J. Teichert
HZDR, Dresden, Germany
H. Vennekate
RI Research Instruments GmbH, Bergisch Gladbach, Germany
I. Will
MBI, Berlin, Germany

Funding: The work was partly supported by the German Federal Ministry of Education and Research (BMBF) grant 05K12CR1 and Deutsche Forschungsgemeinschaft (DFG) project (XI 10⁶/2-1).
The first all-SRF accelerator driven THz source has been operated as a user facility since 2018 at ELBE radiation center. The CW electron beam is extracted from SRF gun II, accelerated to relativistic energies and compressed to sub-ps length in the ELBE SRF linac with a chicane. THz pulses are produced by pass-ing the short electron bunches through a diffraction radiator (CDR) and an undulator. The coherent THz power increases quadratically with bunch charge. The pulse energy up to 10 µJ at 0.3 THz with 100 kHz has been generated.

Poster THP032 [1.207 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP032

About •

paper received ※ 02 July 2019 paper accepted ※ 04 July 2019 issue date ※ 14 August 2019

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

THP041

Impact of the Cu Substrate Surface Preparation on the Morphological, Superconductive and RF Properties of the Nb Superconductive Coatings

laser, cavity, SRF, niobium

935

C. Pira, E. Chyhyrynets
INFN/LNL, Legnaro (PD), Italy
C.Z. Antoine
CEA-IRFU, Gif-sur-Yvette, France
X. Jiang, S.B. Leith, M. Vogel
University Siegen, Siegen, Germany
A. Katasevs, J. Kaupužs, A. Medvids, P. Onufrijevs
Riga Technical University, Riga, Latvia
O. Kugeler
HZB, Berlin, Germany
O.B. Malyshev, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
R. Ries, E. Seiler
Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic
A. Sublet
CERN, Meyrin, Switzerland

Funding: This project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 730871.
Nowadays, one of the main issues of the superconducting thin film resonant cavities is the Cu surface preparation. A better understanding of the impact of copper surface preparation on the morphological, superconductive (SC) and RF properties of the coating, is mandatory in order to improve the performances of superconducting cavities by coating techniques. ARIES H₂020 collaboration includes a specific work package (WP15) to study the influence of Cu surface polishing on the SRF performances of Nb coatings that involves a team of 8 research groups from 7 different countries. In the present work, a comparison of 4 different polishing processes for Cu (Tumbling, EP, SUBU, EP+SUBU) is presented through the evaluation of the SC and morphological properties of Nb thin film coated on Cu planar samples and QPR samples, polished with different procedures. Effects of laser annealing on Nb thin films have also been studied. Different surface characterizations have been applied: roughness measurements, SEM, EDS, XRD, AFM, and thermal and photo-stimulated exoelectrons measurements. SC properties were evaluated with PPMS, and QPR measurements will be carry out at HZB in the beginning of 2019.

Poster THP041 [3.196 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP041

About •

paper received ※ 23 June 2019 paper accepted ※ 05 July 2019 issue date ※ 14 August 2019

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

THP090

Characterization of SSR1 Cavities for PIP-II Linac

cavity, cryomodule, multipactoring, linac

1120

A.I. Sukhanov, F.G. Garcia, B.M. Hanna, S. Kazakov, Y.M. Pischalnikov, O.V. Prokofiev, W. Schappert, I. Terechkine, V.P. Yakovlev, J.C. Yun
Fermilab, Batavia, Illinois, USA
C. Contreras-Martinez
FRIB, East Lansing, Michigan, USA
S. Samani
Queen Mary University of London, London, United Kingdom

A cryomodule of 325 MHz Single Spoke Resonator type 1 (SSR1) superconducting RF cavities is being built at Fermilab for the PIP-II project. Twelve SSR1 cavities were manufactured in industry in USA (10 cavities) and India (2 cavities) and delivered to Fermilab. In this paper we present results of characterization of fully integrated jacketed cavities with high power coupler and tuner at the Fermilab Spoke Test Cryostat (STC).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP090

About •

paper received ※ 23 June 2019 paper accepted ※ 01 July 2019 issue date ※ 14 August 2019

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

THP093

Upgrade on the Experimental Activities for ESS at the LASA Vertical Test Facility

cavity, diagnostics, electron, detector

1133

M. Bertucci, A. Bosotti, A. D’Ambros, P. Michelato, L. Monaco, C. Pagani, R. Paparella, D. Sertore
INFN/LASA, Segrate (MI), Italy

The LASA vertical test facility is equipped for the cold test of ESS medium-beta 704.42 MHz cavities, with and without He tank, and is integrated with several diagnostic tools allowing a careful analysis of cavity performance limitations. This paper reports the latest tests on ESS cavities - both prototypes and series - and a discussion on the experimental results. The recent instrumental upgrades implemented in the facility - and the ones foreseen for the future in view of a further improvement of cavity performances - are also pointed out.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP093

About •

paper received ※ 24 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

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

THP097

Field Emission Studies on ESS Elliptical Prototype Cavities at CEA Saclay

cavity, cryomodule, electron, detector

1147

E. Cenni, M. Baudrier, G. Devanz, L. Maurice, O. Piquet, D. Roudier
CEA-DRF-IRFU, France

CEA Saclay is in charge of the cavity prototypes that is designing, manufacturing, testing and integrating them into demonstrator cryomodules. We have manufactured 6 medium beta and 5 high beta cavities. As part of these activities we are interested in field emission as one of the limiting factors for cavity performances. We are currently collecting data from cavities operated in vertical cryostat and inside cryomodules. Analysis are carried out by means of particle tracking simulation and comparison with radiation dose monitor and scintillators.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP097

About •

paper received ※ 27 June 2019 paper accepted ※ 01 July 2019 issue date ※ 14 August 2019

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FRCAB7

Plasma Processing to Reduce Field Emission in LCLS-II 1.3 GHz SRF Cavities

plasma, cavity, vacuum, HOM

1231

B. Giaccone, J. Zasadzinski
IIT, Chicago, Illinois, USA
P. Berrutti, B. Giaccone, A. Grassellino, M. Martinello
Fermilab, Batavia, Illinois, USA
M. Doleans
ORNL, Oak Ridge, Tennessee, USA
D. Gonnella, G. Lanza, M.C. Ross
SLAC, Menlo Park, California, USA

Plasma cleaning for LCLS-II 9-cell 1.3 GHz cavities is under study at Fermilab. Starting from ORNL method, we have developed a new technique for plasma ignition using HOMs. Plasma processing is being applied to contaminated and field emitting cavities, here are discussed the first results in terms of Q and radiation vs E measured before and after treatment. Further studies are ongoing to optimize plasma parameters and to acquire statistics on plasma cleaning effectiveness.

Slides FRCAB7 [14.701 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-FRCAB7

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paper received ※ 23 June 2019 paper accepted ※ 04 July 2019 issue date ※ 14 August 2019

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