SRF2019 - List of Keywords (dipole)

Paper	Title	Other Keywords	Page
MOP072	FRIB Solenoid Package in Cryomodule and Local Magnetic Shield	solenoid, cavity, cryomodule, operation	235
	K. Saito, H. Ao, B. Bird, R. Bliton, N.K. Bultman, F. Casagrande, C. Compton, J. Curtin, K. Elliott, A. Ganshyn, W. Hartung, L. Hodges, K. Holland, S.H. Kim, S.M. Lidia, D. Luo, S.J. Miller, D.G. Morris, L. Nguyen, D. Norton, J.T. Popielarski, L. Popielarski, T. Russo, J.F. Schwartz, S.M. Shanab, M. Shuptar, D.R. Victory, C. Wei, J. Wei, M. Xu, T. Xu, Y. Yamazaki, C. Zhang, Q. Zhao FRIB, East Lansing, Michigan, USA A. Facco INFN/LNL, Legnaro (PD), Italy K. Hosoyama, M. Masuzawa KEK, Ibaraki, Japan R.E. Laxdal TRIUMF, Vancouver, Canada
	Funding: U.S. Department of Energy Office of Science under Cooperative Agreement DE -SC0000661 FRIB cryomodule design has a feature: solenoid package(s) and local magnetic shields in the cryomodule. In this design, exposing SRF cavities to a very strong fringe field from the solenoid is concerned. A tangled issue between solenoid package design and magnetic shield one has to be resolved. FRIB made intensive studies, designed, prototyped, validated the solenoid packages and magnetic shields, and finally certified them in the bunker test. This paper reports activity results, and LS1 commissioning results in FRIB tunnel. This is a FRIB success story.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP072
About •	paper received ※ 24 June 2019 paper accepted ※ 14 August 2019 issue date ※ 14 August 2019
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TUP018	New SRF Structures Processed at the ANL Cavity Processing Facility	cavity, cathode, SRF, niobium	434
	T. Reid, Z.A. Conway, B.M. Guilfoyle, M. Kedzie, M.P. Kelly, M.K. Ng ANL, Lemont, Illinois, USA
	Argonne National Laboratory (ANL) has extended high quality cavity processing techniques based on those developed for the International Linear Collider to several more complex superconducting RF cavities. Recently, these include a bunch lengthening harmonic cavity, a crabbing rf-dipole cavity, a compact half-wave cavity, and both medium and high frequency elliptical cavities. These systems are an improved version of the one originally developed for 1.3 GHz 9-cell cavities and include a second rotating electrical contact that can support multiple cathodes, necessary for optimum polishing in difficult cavity geometries. All include the possibility for external water cooling.
	Poster TUP018 [4.322 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP018
About •	paper received ※ 28 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)

THP048	Characterization of Flat Multilayer Thin Film Superconductors	superconducting-magnet, experiment, SRF, site	968
	D. Turner, A.J. May STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom G. Burt, L. Gurran Cockcroft Institute, Lancaster University, Lancaster, United Kingdom K.D. Dumbell, N. Pattalwar, S.M. Pattalwar STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom T. Junginger, O.B. Malyshev Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The maximum accelerating gradient of SRF cavities can be increased by raising the field of initial flux penetration, Hvp. Thin alternating layers of superconductors and insulators (SIS) can potentially increase Hvp. Magnetometry is commercially available but consists of limitations, such as SQUID measurements apply a field over both superconducting layers, so Hvp through the sample cannot be measured. If SIS structures are to be investigated a magnetic field must be applied locally, from one plane of the sample, with no magnetic field on the opposing side to allow Hvp to be measured. A magnetic field penetration experiment has been developed at Daresbury laboratory, where a VTI has been created for a cryostat where Hvp of a sample can be measured. The VTI has been designed to allow flat samples to be measured to reduce limitations such as edge effects by creating a DC magnetic field smaller than the sample. A small, parallel magnetic field is produced on the sample by the use of a ferrite yoke. The field is increased to determine Hvp by using 2 hall probes either side of the sample.
	Poster THP048 [0.327 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP048
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)

THP067	Cavity Tilt Measurement in a 1.3 GHz Superconducting Cryo-Module at FLASH	cavity, polarization, HOM, electron	1041
	J.H. Wei USTC/NSRL, Hefei, Anhui, People’s Republic of China N. Baboi DESY, Hamburg, Germany T. Hellert LBNL, Berkeley, California, USA
	TESLA superconducting (SC) cavities are used for the acceleration of electron bunches at FLASH. The Higher Order Modes (HOMs) excited by the beam in these cavities may cause emittance growth. The misalignment of the cavities in a cryo-module is one of the essential factors which enhance the coupling of the HOMs to the beam. The cavity offset and tilt are the two most relevant misalignments. These can be measured by help of dipole modes, based on their linear dependence on the beam offset. The cavity offset has been measured before in several modules at FLASH. However, the cavity tilt has so far proved to be difficult to be measured, because the angular dependence of the dipole mode is much weaker. By carefully targeting the beam through the middle of a cavity, the strong offset contribution to the dipole fields could be reduced. Careful data analysis based on a fitting method enabled us then to extract the information on the cavity tilt. This measurement has been implemented in the cavities in one cryo-module at FLASH. First results of the ongoing measurements from several cavities are presented in this paper. It is for the first time that the cavity tilt in several cavities has been measured.
	Poster THP067 [1.392 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP067
About •	paper received ※ 23 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)

THP104	Numerical Estimation of Beam Break-Up Instability in TESLA Cavities	cavity, solenoid, linac, focusing	1178
	V. Volkov, V.M. Petrov BINP SB RAS, Novosibirsk, Russia
	In this article the numerically estimated BBU instability behaviors of a 9 cell superconducting TESLA cavity are presented for first two pass-band trapped dipole modes (18 in all). The given BBU threshold current values are calculated by the method of beam energy gain averaging on phases of dipole mode fields. BBU instability behaviors in cases of applying the cavities in Linacs as well in Energy Recovery Linacs (ERLs) are considered. The BBU influence on beam emittance degradation is demonstrated. Examples for suppression of beam BBU oscillations by a solenoid focusing and applying of an external RF generator with a feedback are visualized.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP104
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)

Paper

Title

Other Keywords

Page

MOP072

FRIB Solenoid Package in Cryomodule and Local Magnetic Shield

solenoid, cavity, cryomodule, operation

235

K. Saito, H. Ao, B. Bird, R. Bliton, N.K. Bultman, F. Casagrande, C. Compton, J. Curtin, K. Elliott, A. Ganshyn, W. Hartung, L. Hodges, K. Holland, S.H. Kim, S.M. Lidia, D. Luo, S.J. Miller, D.G. Morris, L. Nguyen, D. Norton, J.T. Popielarski, L. Popielarski, T. Russo, J.F. Schwartz, S.M. Shanab, M. Shuptar, D.R. Victory, C. Wei, J. Wei, M. Xu, T. Xu, Y. Yamazaki, C. Zhang, Q. Zhao
FRIB, East Lansing, Michigan, USA
A. Facco
INFN/LNL, Legnaro (PD), Italy
K. Hosoyama, M. Masuzawa
KEK, Ibaraki, Japan
R.E. Laxdal
TRIUMF, Vancouver, Canada

Funding: U.S. Department of Energy Office of Science under Cooperative Agreement DE -SC0000661
FRIB cryomodule design has a feature: solenoid package(s) and local magnetic shields in the cryomodule. In this design, exposing SRF cavities to a very strong fringe field from the solenoid is concerned. A tangled issue between solenoid package design and magnetic shield one has to be resolved. FRIB made intensive studies, designed, prototyped, validated the solenoid packages and magnetic shields, and finally certified them in the bunker test. This paper reports activity results, and LS1 commissioning results in FRIB tunnel. This is a FRIB success story.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP072

About •

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

Export •

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

TUP018

New SRF Structures Processed at the ANL Cavity Processing Facility

cavity, cathode, SRF, niobium

434

T. Reid, Z.A. Conway, B.M. Guilfoyle, M. Kedzie, M.P. Kelly, M.K. Ng
ANL, Lemont, Illinois, USA

Argonne National Laboratory (ANL) has extended high quality cavity processing techniques based on those developed for the International Linear Collider to several more complex superconducting RF cavities. Recently, these include a bunch lengthening harmonic cavity, a crabbing rf-dipole cavity, a compact half-wave cavity, and both medium and high frequency elliptical cavities. These systems are an improved version of the one originally developed for 1.3 GHz 9-cell cavities and include a second rotating electrical contact that can support multiple cathodes, necessary for optimum polishing in difficult cavity geometries. All include the possibility for external water cooling.

Poster TUP018 [4.322 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP018

About •

paper received ※ 28 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)

THP048

Characterization of Flat Multilayer Thin Film Superconductors

superconducting-magnet, experiment, SRF, site

968

D. Turner, A.J. May
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
G. Burt, L. Gurran
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
K.D. Dumbell, N. Pattalwar, S.M. Pattalwar
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
T. Junginger, O.B. Malyshev
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The maximum accelerating gradient of SRF cavities can be increased by raising the field of initial flux penetration, Hvp. Thin alternating layers of superconductors and insulators (SIS) can potentially increase Hvp. Magnetometry is commercially available but consists of limitations, such as SQUID measurements apply a field over both superconducting layers, so Hvp through the sample cannot be measured. If SIS structures are to be investigated a magnetic field must be applied locally, from one plane of the sample, with no magnetic field on the opposing side to allow Hvp to be measured. A magnetic field penetration experiment has been developed at Daresbury laboratory, where a VTI has been created for a cryostat where Hvp of a sample can be measured. The VTI has been designed to allow flat samples to be measured to reduce limitations such as edge effects by creating a DC magnetic field smaller than the sample. A small, parallel magnetic field is produced on the sample by the use of a ferrite yoke. The field is increased to determine Hvp by using 2 hall probes either side of the sample.

Poster THP048 [0.327 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP048

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)

THP067

Cavity Tilt Measurement in a 1.3 GHz Superconducting Cryo-Module at FLASH

cavity, polarization, HOM, electron

1041

J.H. Wei
USTC/NSRL, Hefei, Anhui, People’s Republic of China
N. Baboi
DESY, Hamburg, Germany
T. Hellert
LBNL, Berkeley, California, USA

TESLA superconducting (SC) cavities are used for the acceleration of electron bunches at FLASH. The Higher Order Modes (HOMs) excited by the beam in these cavities may cause emittance growth. The misalignment of the cavities in a cryo-module is one of the essential factors which enhance the coupling of the HOMs to the beam. The cavity offset and tilt are the two most relevant misalignments. These can be measured by help of dipole modes, based on their linear dependence on the beam offset. The cavity offset has been measured before in several modules at FLASH. However, the cavity tilt has so far proved to be difficult to be measured, because the angular dependence of the dipole mode is much weaker. By carefully targeting the beam through the middle of a cavity, the strong offset contribution to the dipole fields could be reduced. Careful data analysis based on a fitting method enabled us then to extract the information on the cavity tilt. This measurement has been implemented in the cavities in one cryo-module at FLASH. First results of the ongoing measurements from several cavities are presented in this paper. It is for the first time that the cavity tilt in several cavities has been measured.

Poster THP067 [1.392 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP067

About •

paper received ※ 23 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)

THP104

Numerical Estimation of Beam Break-Up Instability in TESLA Cavities

cavity, solenoid, linac, focusing

1178

V. Volkov, V.M. Petrov
BINP SB RAS, Novosibirsk, Russia

In this article the numerically estimated BBU instability behaviors of a 9 cell superconducting TESLA cavity are presented for first two pass-band trapped dipole modes (18 in all). The given BBU threshold current values are calculated by the method of beam energy gain averaging on phases of dipole mode fields. BBU instability behaviors in cases of applying the cavities in Linacs as well in Energy Recovery Linacs (ERLs) are considered. The BBU influence on beam emittance degradation is demonstrated. Examples for suppression of beam BBU oscillations by a solenoid focusing and applying of an external RF generator with a feedback are visualized.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP104

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)