SRF2019 - List of Keywords (GUI)

Paper	Title	Other Keywords	Page
MOP036	Microphonics Suppression Study in ARIEL e-Linac Cryomodules	cavity, cryomodule, linac, pick-up	136
	Y. Ma, K. Fong, J.J. Keir, D. Kishi, S.R. Koscielniak, D. Lang, R.E. Laxdal, S.L. Liu, R.S. Sekhon, X. Wang TRIUMF, Vancouver, Canada
	Now the stage of the 30 MeV portion of ARIEL (The Advanced Rare Isotope Laboratory) e-Linac (1.3 GHz, SRF) is under commissioning which includes an injector cryomodule (ICM) with a single nine-cell cavity and the 1st accelerator cryomodule (ACM1) with two cavities configuration. The two ACM1 cavities are driven by a single klystron with vector-sum control and running in CW mode. We have observed a ponderomotive instability in ACM1 driven by the Lorentz force and seeded through microphonics that impacts beam stability [1-5]. Extensive damping has been implemented during a recent shut-down. The beam test results show 20 MeV acceleration gain can be reached by ACM1. A fast piezoelectric (Pie-zo) tuner is under development to allow a fast tuning compensation for the e-Linac cavities. In this paper, the progress of the microphonics suppression of Cryomod-ules is presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP036
About •	paper received ※ 24 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)

MOP077	Ceramic Study on RF Windows for Power Coupler, Waveguide, and Klystron in Particle Accelerator	electron, klystron, operation, multipactoring	255
	Y. Yamamoto, S. Michizono KEK, Ibaraki, Japan
	R&Ds on different types of ceramic used in power coupler, waveguide, and klystron for particle accelerators are under progress in Center of Innovation (COI) at KEK, and at some outside companies. There are five important parameters on the properties of ceramics; that is, relative permittivity, dielectric loss tangent, surface and volume resistivity, and secondary electron emission coefficient. For measurements of these parameters, eight kinds of ceramic samples supplied from five vendors have been measured using three different measurement systems since 2017. In this report, the recent results for these studies will be presented in detail.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP077
About •	paper received ※ 22 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)

TUP036	Commissioning of Klystron Transmitters with 270 kW_CW at 1.3 GHz	klystron, cavity, power-supply, SRF	499
	B. Schriefer, W. Anders, A. Heugel, H. Hoffmann, G. Mielczarek, H. Stein HZB, Berlin, Germany
	In Berlin-Adlershof the Helmholtz-Zentrum Berlin (HZB) is constructing the energy recovery linac ¿BERLinPro¿. Three klystron transmitters each 270 kWCW at 1.3 GHz are installed at the injection path of the ERL. The RF plant includes circulators and water loads. This paper describes the commissioning of the first klystron, calibration of the RF level control system as well as comparison with calorimetric output power measurements to verify the results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP036
About •	paper received ※ 03 November 2019 paper accepted ※ 03 November 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP081	Status of the HL-LHC Crab Cavity Tuner	cavity, cryomodule, SRF, vacuum	646
	K. Artoos, L. Arnaudon, R. Calaga, E. Cano-Pleite, O. Capatina, T. Capelli, D.F. Cartaxo dos Santos, M. Garlasché, D.C. Glenat, A. Krawczyk, R. Leuxe, P. Minginette, J.S. Swieszek CERN, Geneva, Switzerland T.J. Jones STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom A. Krawczyk, B. Prochal IFJ-PAN, Kraków, Poland J.A. Mitchell Lancaster University, Lancaster, United Kingdom S. Verdú-Andrés BNL, Upton, New York, USA
	Funding: Research supported by the HL-LHC project The resonance frequency of the HL-LHC Double Quarter Wave (DQW) and Radio Frequency Dipole (RFD) crab cavities is set to the operating frequency of 400.79 MHz by deforming the cavities. For both types of cavities, the tuning principle foresees a symmetric mechanical deformation of parts of the cavities in vertical direction, with the tuner motor placed outside on top of the vacuum vessel. The tuner design was successfully tested on the DQW prototype cryomodule with two cavities in 2018 in the SPS at CERN. This paper describes the design of DQW and RFD crab tuners. The experience and results of assembly and cold testing is given together with some required improvements. Finally, the final series crab tuners preparation is reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP081
About •	paper received ※ 21 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)

WETEB2	Identifying Specific Cryomodule and Cleanroom Particulate Contamination: Understanding Legacy Issues and Providing New Feedback Standards	cavity, cryomodule, SRF, feedback	758
	C.E. Reece, J.K. Spradlin, O. Trofimova, A-M. Valente-Feliciano JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. While the techniques used to provide "UHV clean" and "particle-free" beamline components, including SRF cavities, continue to evolve, "real-world" operating machines must deal with actual accumulated and latent contamination issues that produce non-trivial cryogenic heatload, radiation, activation, and degradation via field emission. We have developed a standardized and automated particulate contamination assay method for use in characterizing particulates found on beamline components and in cleanroom assembly environments. We present results from using this system to analyze samples taken from reworked cryomodules from CEBAF. Particle sizes are much larger than anticipated. Utility for feedback on sources to enable improved source reduction is explored.
	Slides WETEB2 [13.320 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-WETEB2
About •	paper received ※ 23 June 2019 paper accepted ※ 02 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WETEB9	Design Development for the 1.5 GHz Couplers for BESSY VSR	operation, cavity, coupling, diagnostics	795
	E. Sharples, M. Dirsat, J. Knobloch, Z. Muza, A.V. Vélez HZB, Berlin, Germany
	The Variable pulse length Storage Ring (BESSY VSR) is a superconducting radio frequency (SRF) upgrade to the existing BESSY II storage ring at Helmholtz-Zentrum Berlin (HZB). BESSY VSR uses the RF beating of superconducting cavities at 1.5 GHz and 1.75 GHz to produce simultaneously long and short bunches. Higher power couplers capable of handling 13 kW peak power at standing wave operation, are required to provide an average power of 1.5 kW for both the 1.5 GHz and 1.75 GHz cavities. These couplers must also provide variable coupling with a range of Q_ext from 6x10⁶ to 6x10⁷ to allow flexibility to adjust to operating conditions of BESSY VSR. Here the full design development process for the 1.5 GHZ BESSY VSR coupler is presented including the design for a diagnostic prototype to ensure comprehensive monitoring of critical components during testing and cool-down.
	Slides WETEB9 [8.085 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-WETEB9
About •	paper received ※ 23 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)

THP014	First Direct Imaging and Profiling TOF-SIMS Studies on Cutouts from Cavities Prepared by State-of-the-Art Treatments	cavity, niobium, SRF, superconductivity	866
	A.S. Romanenko, A. Grassellino, M. Martinello, Y. Trenikhina Fermilab, Batavia, Illinois, USA D. Bafia Illinois Institute of Technology, Chicago, Illinois, USA
	Funding: This work has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. Small amounts of interstitial impurities in the penetra-tion depth of superconducting radio frequency (SRF) cavities have a dramatic effect on the quality factors and maximum accelerating gradients. Here we report the first TOF-SIMS studies of cutouts from cavities prepared by all modern surface treatments, which allow a direct corre-lation of the impurity distribution with the observed cavity performance. Imaging capability of our instrument allows to avoid the possible issues associated with the ‘‘ghost’’ depth profiles appearing as a consequence of particulate surface contamination, which likely caused the inconclusive SIMS results on e.g. oxygen diffusion in the past.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP014
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)

THP025	Overview of Superconducting RF Cavity Reliability at Diamond Light Source	cavity, vacuum, operation, storage-ring	885
	C. Christou, P. Gu, P.J. Marten, S.A. Pande, A.F. Rankin, D. Spink, L.T. Stant, A. Tropp DLS, Oxfordshire, United Kingdom
	Diamond Light Source has been providing beam for users since January 2007. The electron beam in the storage ring is normally driven by two superconducting CESR-B cavities, with two similar cavities available as spares. Day-to-day reliability of the cavities, measured by storage ring MTBF, has improved enormously over the years. A full analysis of how this improvement has been achieved is given, with particular attention paid to cavity voltage and vacuum pressure management, and the scheduling and procedure of cavity conditioning. The benefits and risks of full and partial warm-ups of the cavities are discussed, and details and impacts of cavity failure and repair are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP025
About •	paper received ※ 21 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)

THP088	Updates on the Inspection System for SRF Cavities	cavity, controls, superconducting-cavity, interface	1111
	Y. Iwashita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan H. Hayano KEK, Ibaraki, Japan Y. Kuriyama Kyoto University, Research Reactor Institute, Osaka, Japan
	Optical inspections on superconducting cavities are familiar to those who are involved in the cavity fabrications. Further improvements on the Kyoto Camera have been carried out these years together with further processing technique developments, such as removing found defects by local grinding techniques. Improvements on Kyoto Camera includes implementation of color LEDs for illumination system, which improves the inspection efficiency. These progresses will be reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP088
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)

Paper

Title

Other Keywords

Page

MOP036

Microphonics Suppression Study in ARIEL e-Linac Cryomodules

cavity, cryomodule, linac, pick-up

136

Y. Ma, K. Fong, J.J. Keir, D. Kishi, S.R. Koscielniak, D. Lang, R.E. Laxdal, S.L. Liu, R.S. Sekhon, X. Wang
TRIUMF, Vancouver, Canada

Now the stage of the 30 MeV portion of ARIEL (The Advanced Rare Isotope Laboratory) e-Linac (1.3 GHz, SRF) is under commissioning which includes an injector cryomodule (ICM) with a single nine-cell cavity and the 1st accelerator cryomodule (ACM1) with two cavities configuration. The two ACM1 cavities are driven by a single klystron with vector-sum control and running in CW mode. We have observed a ponderomotive instability in ACM1 driven by the Lorentz force and seeded through microphonics that impacts beam stability [1-5]. Extensive damping has been implemented during a recent shut-down. The beam test results show 20 MeV acceleration gain can be reached by ACM1. A fast piezoelectric (Pie-zo) tuner is under development to allow a fast tuning compensation for the e-Linac cavities. In this paper, the progress of the microphonics suppression of Cryomod-ules is presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP036

About •

paper received ※ 24 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)

MOP077

Ceramic Study on RF Windows for Power Coupler, Waveguide, and Klystron in Particle Accelerator

electron, klystron, operation, multipactoring

255

Y. Yamamoto, S. Michizono
KEK, Ibaraki, Japan

R&Ds on different types of ceramic used in power coupler, waveguide, and klystron for particle accelerators are under progress in Center of Innovation (COI) at KEK, and at some outside companies. There are five important parameters on the properties of ceramics; that is, relative permittivity, dielectric loss tangent, surface and volume resistivity, and secondary electron emission coefficient. For measurements of these parameters, eight kinds of ceramic samples supplied from five vendors have been measured using three different measurement systems since 2017. In this report, the recent results for these studies will be presented in detail.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP077

About •

paper received ※ 22 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)

TUP036

Commissioning of Klystron Transmitters with 270 kW_CW at 1.3 GHz

klystron, cavity, power-supply, SRF

499

B. Schriefer, W. Anders, A. Heugel, H. Hoffmann, G. Mielczarek, H. Stein
HZB, Berlin, Germany

In Berlin-Adlershof the Helmholtz-Zentrum Berlin (HZB) is constructing the energy recovery linac ¿BERLinPro¿. Three klystron transmitters each 270 kWCW at 1.3 GHz are installed at the injection path of the ERL. The RF plant includes circulators and water loads. This paper describes the commissioning of the first klystron, calibration of the RF level control system as well as comparison with calorimetric output power measurements to verify the results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP036

About •

paper received ※ 03 November 2019 paper accepted ※ 03 November 2019 issue date ※ 14 August 2019

Export •

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

TUP081

Status of the HL-LHC Crab Cavity Tuner

cavity, cryomodule, SRF, vacuum

646

K. Artoos, L. Arnaudon, R. Calaga, E. Cano-Pleite, O. Capatina, T. Capelli, D.F. Cartaxo dos Santos, M. Garlasché, D.C. Glenat, A. Krawczyk, R. Leuxe, P. Minginette, J.S. Swieszek
CERN, Geneva, Switzerland
T.J. Jones
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
A. Krawczyk, B. Prochal
IFJ-PAN, Kraków, Poland
J.A. Mitchell
Lancaster University, Lancaster, United Kingdom
S. Verdú-Andrés
BNL, Upton, New York, USA

Funding: Research supported by the HL-LHC project
The resonance frequency of the HL-LHC Double Quarter Wave (DQW) and Radio Frequency Dipole (RFD) crab cavities is set to the operating frequency of 400.79 MHz by deforming the cavities. For both types of cavities, the tuning principle foresees a symmetric mechanical deformation of parts of the cavities in vertical direction, with the tuner motor placed outside on top of the vacuum vessel. The tuner design was successfully tested on the DQW prototype cryomodule with two cavities in 2018 in the SPS at CERN. This paper describes the design of DQW and RFD crab tuners. The experience and results of assembly and cold testing is given together with some required improvements. Finally, the final series crab tuners preparation is reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP081

About •

paper received ※ 21 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)

WETEB2

Identifying Specific Cryomodule and Cleanroom Particulate Contamination: Understanding Legacy Issues and Providing New Feedback Standards

cavity, cryomodule, SRF, feedback

758

C.E. Reece, J.K. Spradlin, O. Trofimova, A-M. Valente-Feliciano
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
While the techniques used to provide "UHV clean" and "particle-free" beamline components, including SRF cavities, continue to evolve, "real-world" operating machines must deal with actual accumulated and latent contamination issues that produce non-trivial cryogenic heatload, radiation, activation, and degradation via field emission. We have developed a standardized and automated particulate contamination assay method for use in characterizing particulates found on beamline components and in cleanroom assembly environments. We present results from using this system to analyze samples taken from reworked cryomodules from CEBAF. Particle sizes are much larger than anticipated. Utility for feedback on sources to enable improved source reduction is explored.

Slides WETEB2 [13.320 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-WETEB2

About •

paper received ※ 23 June 2019 paper accepted ※ 02 July 2019 issue date ※ 14 August 2019

Export •

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

WETEB9

Design Development for the 1.5 GHz Couplers for BESSY VSR

operation, cavity, coupling, diagnostics

795

E. Sharples, M. Dirsat, J. Knobloch, Z. Muza, A.V. Vélez
HZB, Berlin, Germany

The Variable pulse length Storage Ring (BESSY VSR) is a superconducting radio frequency (SRF) upgrade to the existing BESSY II storage ring at Helmholtz-Zentrum Berlin (HZB). BESSY VSR uses the RF beating of superconducting cavities at 1.5 GHz and 1.75 GHz to produce simultaneously long and short bunches. Higher power couplers capable of handling 13 kW peak power at standing wave operation, are required to provide an average power of 1.5 kW for both the 1.5 GHz and 1.75 GHz cavities. These couplers must also provide variable coupling with a range of Q_ext from 6x10⁶ to 6x10⁷ to allow flexibility to adjust to operating conditions of BESSY VSR. Here the full design development process for the 1.5 GHZ BESSY VSR coupler is presented including the design for a diagnostic prototype to ensure comprehensive monitoring of critical components during testing and cool-down.

Slides WETEB9 [8.085 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-WETEB9

About •

paper received ※ 23 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)

THP014

First Direct Imaging and Profiling TOF-SIMS Studies on Cutouts from Cavities Prepared by State-of-the-Art Treatments

cavity, niobium, SRF, superconductivity

866

A.S. Romanenko, A. Grassellino, M. Martinello, Y. Trenikhina
Fermilab, Batavia, Illinois, USA
D. Bafia
Illinois Institute of Technology, Chicago, Illinois, USA

Funding: This work has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
Small amounts of interstitial impurities in the penetra-tion depth of superconducting radio frequency (SRF) cavities have a dramatic effect on the quality factors and maximum accelerating gradients. Here we report the first TOF-SIMS studies of cutouts from cavities prepared by all modern surface treatments, which allow a direct corre-lation of the impurity distribution with the observed cavity performance. Imaging capability of our instrument allows to avoid the possible issues associated with the ‘‘ghost’’ depth profiles appearing as a consequence of particulate surface contamination, which likely caused the inconclusive SIMS results on e.g. oxygen diffusion in the past.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP014

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)

THP025

Overview of Superconducting RF Cavity Reliability at Diamond Light Source

cavity, vacuum, operation, storage-ring

885

C. Christou, P. Gu, P.J. Marten, S.A. Pande, A.F. Rankin, D. Spink, L.T. Stant, A. Tropp
DLS, Oxfordshire, United Kingdom

Diamond Light Source has been providing beam for users since January 2007. The electron beam in the storage ring is normally driven by two superconducting CESR-B cavities, with two similar cavities available as spares. Day-to-day reliability of the cavities, measured by storage ring MTBF, has improved enormously over the years. A full analysis of how this improvement has been achieved is given, with particular attention paid to cavity voltage and vacuum pressure management, and the scheduling and procedure of cavity conditioning. The benefits and risks of full and partial warm-ups of the cavities are discussed, and details and impacts of cavity failure and repair are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP025

About •

paper received ※ 21 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)

THP088

Updates on the Inspection System for SRF Cavities

cavity, controls, superconducting-cavity, interface

1111

Y. Iwashita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
H. Hayano
KEK, Ibaraki, Japan
Y. Kuriyama
Kyoto University, Research Reactor Institute, Osaka, Japan

Optical inspections on superconducting cavities are familiar to those who are involved in the cavity fabrications. Further improvements on the Kyoto Camera have been carried out these years together with further processing technique developments, such as removing found defects by local grinding techniques. Improvements on Kyoto Camera includes implementation of color LEDs for illumination system, which improves the inspection efficiency. These progresses will be reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP088

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)