SRF2019 - List of Authors (Laxdal, R.E.)

Paper	Title	Page
MOFAA3	The FRIB SC-Linac - Installation and Phased Commissioning	12
	J. Wei, H. Ao, S. Beher, B. Bird, N.K. Bultman, F. Casagrande, D. Chabot, W. Chang, S. Cogan, C. Compton, J. Curtin, K.D. Davidson, E. Daykin, K. Elliott, A. Facco, A. Fila, V. Ganni, A. Ganshyn, P.E. Gibson, T. Glasmacher, I. Grender, W. Hartung, L. Hodges, K. Holland, H.-C. Hseuh, A. Hussain, M. Ikegami, S. Jones, T. Kanemura, S.H. Kim, P. Knudsen, M.G. Konrad, J. LeTourneau, Z. Li, S.M. Lidia, G. Machicoane, P. Manwiller, F. Marti, T. Maruta, E.S. Metzgar, S.J. Miller, D.G. Morris, C. Nguyen, K. Openlander, P.N. Ostroumov, A.S. Plastun, J.T. Popielarski, L. Popielarski, J. Priller, M.A. Reaume, H.T. Ren, T. Russo, K. Saito, M. Shuptar, J.W. Stetson, D.R. Victory, R. Walker, X. Wang, J.D. Wenstrom, M. Wright, M. Xu, T. Xu, Y. Yamazaki, Q. Zhao, S. Zhao FRIB, East Lansing, Michigan, USA K. Dixon, M. Wiseman JLab, Newport News, Virginia, USA A. Facco INFN/LNL, Legnaro (PD), Italy K. Hosoyama KEK, Ibaraki, Japan M.P. Kelly ANL, Lemont, Illinois, USA R.E. Laxdal TRIUMF, Vancouver, Canada
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. The Facility for Rare Isotope Beams (FRIB) superconducting (SC) driver linac is designed to accelerate all stable ions including uranium to energies above 200 MeV/u primarily with 46 cryomodules containing 324 quarter-wave resonators (QWR) and half-wave (HWR) resonators. With the newly commissioned helium refrigeration system supplying liquid helium to the QWR and solenoids, heavy ion beams including Ne, Ar, Kr and Xe were accelerated to the charge stripper location above 20 MeV/u with the first linac segment consisting of 15 cryomodules containing 10⁴ QWRs of β=0.041 and 0.085 and 39 solenoids. Installation of cryomodules with β=0.29 and 0.53 HWRs is proceeding in parallel. Development of β=0.65 elliptical resonators is on-going supporting the FRIB energy upgrade to 400 MeV/u. This paper summarizes the SC-linac installation and phased commissioning status that is on schedule and on budget to the FRIB project.
	Slides MOFAA3 [46.571 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOFAA3
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)

MOP036	Microphonics Suppression Study in ARIEL e-Linac Cryomodules	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)

MOP072	FRIB Solenoid Package in Cryomodule and Local Magnetic Shield	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)

MOP076	Fundamental Power Coupler Design for a 325 MHz Balloon SSR Cavity	252
	R.E. Laxdal, Y. Ma, B. Matheson, B.S. Waraich, Z.Y. Yao, V. Zvyagintsev TRIUMF, Vancouver, Canada
	TRIUMF has designed, fabricated and tested the first balloon variant of the single spoke resonator at 325 MHz and β=0.3. TRIUMF has also designed a 6 kW fundamental power coupler as part of the development. The design of the coupler will be presented.
	Poster MOP076 [1.282 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP076
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)

TUFUA7	Review of Muon Spin Rotation Studies of SRF Materials	360
	T. Junginger Lancaster University, Lancaster, United Kingdom R.E. Laxdal TRIUMF, Vancouver, Canada
	Muons spin rotate in magnetic fields and emit a positron preferentially in spin direction after decay. These properties enable muon spin rotation (muSR) as a precise probe for local magnetism. muSR has been used to characterize SRF materials since 2010. At TRIUMF a so called surface beam implants muons at a material dependent depth of about 150 µm in the bulk. A dedicated spectrometer was developed for field of first vortex penetration and pinning strength measurements of SRF materials in parallel magnetic fields of up to 300 mT. A low energy beam available at PSI implants muons at variable depth in the London layer allowing for direct measurements of the London penetration depth from which the lower critical field and the superheating field can be calculated. This facility is limited to parallel magnetic fields of up to 25 mT. Here, surface and low energy muSR results on SRF materials are reviewed and cross-correlated to each other and to further results from additional experiments. Finally, we present the status of a new facility based on the similar beta-NMR technique enabling measurements in the London layer of SRF materials exposed to parallel magnetic fields above 200 mT.
	Slides TUFUA7 [4.063 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUFUA7
About •	paper received ※ 01 July 2019 paper accepted ※ 12 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP046	Low Frequency, Low Beta Cavity Performance Improvement Studies	527
	P. Kolb, R.E. Laxdal, Z.Y. Yao TRIUMF, Vancouver, Canada
	In recent years, new discoveries such as N₂ doping and infusion lead to a significant increases in Q₀ and accelerating gradient for 1.3 GHz, β=1 elliptical cavities. To understand and to adapt these treatments for lower frequency, \beta < 1 cavities, two coaxial test cavities, one quarter-wave resonator (QWR) and one half-wave resonator (HWR), have been built and put through a systematic study of these new treatments to show the effectiveness of these treatments at different frequencies. These cavities are tested in their fundamental mode and several higher order modes to study the frequency dependence of new cavity treatments such as N₂ doping and infusion. Results of these studies are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP046
About •	paper received ※ 22 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)

TUP106	Mechanical Tuner for a 325 MHz Balloon Single Spoke Resonator	730
	R.E. Laxdal, J.J. Keir, B. Matheson, N. Muller, Z.Y. Yao TRIUMF, Vancouver, Canada
	TRIUMF has designed, fabricated and tested the first balloon variant of the single spoke resonator at 325 MHz and β=0.3. TRIUMF has also designed and built a mechanical tuner as part of the development. The tuner employs a nutcracker lever pressing at the beam ports driven by a scissor jack. The scissor is actuated through a tube coupling to a warm ball-screw and servo-motor located outside the cryostat. The design and warm tests of the tuner will be presented.
	Poster TUP106 [1.089 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP106
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)

THP047	Progress of TRIUMF Beta-SRF Facility for Novel SRF Materials	964
SUSP003	use link to see paper's listing under its alternate paper code
	E. Thoeng UBC & TRIUMF, Vancouver, British Columbia, Canada R.A. Baartman, P. Kolb, R.E. Laxdal, B. Matheson, G. Morris, N. Muller, S. Saminathan TRIUMF, Vancouver, Canada T. Junginger UVIC, Victoria, Canada
	Funding: NSERC (Natural Sciences and Engineering Research Council of Canada) SRF cavities made with bulk Nb have been the backbone of high-power modern linear accelerators. Demands for higher energy and more efficient linear accelerators, however, have strained the capabilities of bulk Nb close to its fundamental limit. Several routes have been proposed using thin film novel superconductors (e.g. Nb₃Sn), SIS multilayer, and N-doping. Beta-NMR techniques are more suitable for the characterization of Meissner state in these materials, due to the capability of soft-landing radioactive ions on the nanometer scale of London penetration depth, as compared to micrometer probe of the muSR technique. Upgrade of the existing beta-NQR beamline, combined with the capability of high parallel magnetic field (200 mT) are the scope of the beta-SRF facility which has been fully funded. All hardware required for the upgrade has also been procured. The status of the commissioning, which is currently in phase I, is reported here, together with the future schedule of phase II with the fully installed beta-SRF beamline. Finally, the detail layout of the completed beamline and sample requirements will be included in this paper which might be of interest of future users.
	Poster THP047 [1.372 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP047
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)

FRCAA2	Balloon Single Spoke Resonator - A New Variant for Reduced Multipacting
	Z.Y. Yao, R.E. Laxdal TRIUMF, Vancouver, Canada
	Spoke resonators have been widely proposed and optimized for various applications. Good performance has been demonstrated by many cavity tests. Accompanying the great progress, the adverse impact of strong multipacting (MP) is also noted, consistent with modern 3D simulations. This paper will discuss MP behaviors in the single spoke resonator (SSR). In particular a phenomenological theory is developed to highlight the details of the geometry that affect MP. The analysis leads to an optimized geometry of a single spoke resonator defined here as the ’balloon’ geometry. TRIUMF has designed, fabricated and tested the first balloon SSR at 325 MHz and β=0.3. Cold tests proved the principle of the balloon concept, the elimination of MP barriers around the operational gradient. This paper will also report the details of the mechanical and RF design, the fabrication steps and recent cold test results.
	Slides FRCAA2 [19.831 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

The FRIB SC-Linac - Installation and Phased Commissioning

12

J. Wei, H. Ao, S. Beher, B. Bird, N.K. Bultman, F. Casagrande, D. Chabot, W. Chang, S. Cogan, C. Compton, J. Curtin, K.D. Davidson, E. Daykin, K. Elliott, A. Facco, A. Fila, V. Ganni, A. Ganshyn, P.E. Gibson, T. Glasmacher, I. Grender, W. Hartung, L. Hodges, K. Holland, H.-C. Hseuh, A. Hussain, M. Ikegami, S. Jones, T. Kanemura, S.H. Kim, P. Knudsen, M.G. Konrad, J. LeTourneau, Z. Li, S.M. Lidia, G. Machicoane, P. Manwiller, F. Marti, T. Maruta, E.S. Metzgar, S.J. Miller, D.G. Morris, C. Nguyen, K. Openlander, P.N. Ostroumov, A.S. Plastun, J.T. Popielarski, L. Popielarski, J. Priller, M.A. Reaume, H.T. Ren, T. Russo, K. Saito, M. Shuptar, J.W. Stetson, D.R. Victory, R. Walker, X. Wang, J.D. Wenstrom, M. Wright, M. Xu, T. Xu, Y. Yamazaki, Q. Zhao, S. Zhao
FRIB, East Lansing, Michigan, USA
K. Dixon, M. Wiseman
JLab, Newport News, Virginia, USA
A. Facco
INFN/LNL, Legnaro (PD), Italy
K. Hosoyama
KEK, Ibaraki, Japan
M.P. Kelly
ANL, Lemont, Illinois, USA
R.E. Laxdal
TRIUMF, Vancouver, Canada

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The Facility for Rare Isotope Beams (FRIB) superconducting (SC) driver linac is designed to accelerate all stable ions including uranium to energies above 200 MeV/u primarily with 46 cryomodules containing 324 quarter-wave resonators (QWR) and half-wave (HWR) resonators. With the newly commissioned helium refrigeration system supplying liquid helium to the QWR and solenoids, heavy ion beams including Ne, Ar, Kr and Xe were accelerated to the charge stripper location above 20 MeV/u with the first linac segment consisting of 15 cryomodules containing 10⁴ QWRs of β=0.041 and 0.085 and 39 solenoids. Installation of cryomodules with β=0.29 and 0.53 HWRs is proceeding in parallel. Development of β=0.65 elliptical resonators is on-going supporting the FRIB energy upgrade to 400 MeV/u. This paper summarizes the SC-linac installation and phased commissioning status that is on schedule and on budget to the FRIB project.

Slides MOFAA3 [46.571 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOFAA3

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)

MOP036

Microphonics Suppression Study in ARIEL e-Linac Cryomodules

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)

MOP072

FRIB Solenoid Package in Cryomodule and Local Magnetic Shield

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)

MOP076

Fundamental Power Coupler Design for a 325 MHz Balloon SSR Cavity

252

R.E. Laxdal, Y. Ma, B. Matheson, B.S. Waraich, Z.Y. Yao, V. Zvyagintsev
TRIUMF, Vancouver, Canada

TRIUMF has designed, fabricated and tested the first balloon variant of the single spoke resonator at 325 MHz and β=0.3. TRIUMF has also designed a 6 kW fundamental power coupler as part of the development. The design of the coupler will be presented.

Poster MOP076 [1.282 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP076

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)

TUFUA7

Review of Muon Spin Rotation Studies of SRF Materials

360

T. Junginger
Lancaster University, Lancaster, United Kingdom
R.E. Laxdal
TRIUMF, Vancouver, Canada

Muons spin rotate in magnetic fields and emit a positron preferentially in spin direction after decay. These properties enable muon spin rotation (muSR) as a precise probe for local magnetism. muSR has been used to characterize SRF materials since 2010. At TRIUMF a so called surface beam implants muons at a material dependent depth of about 150 µm in the bulk. A dedicated spectrometer was developed for field of first vortex penetration and pinning strength measurements of SRF materials in parallel magnetic fields of up to 300 mT. A low energy beam available at PSI implants muons at variable depth in the London layer allowing for direct measurements of the London penetration depth from which the lower critical field and the superheating field can be calculated. This facility is limited to parallel magnetic fields of up to 25 mT. Here, surface and low energy muSR results on SRF materials are reviewed and cross-correlated to each other and to further results from additional experiments. Finally, we present the status of a new facility based on the similar beta-NMR technique enabling measurements in the London layer of SRF materials exposed to parallel magnetic fields above 200 mT.

Slides TUFUA7 [4.063 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUFUA7

About •

paper received ※ 01 July 2019 paper accepted ※ 12 July 2019 issue date ※ 14 August 2019

Export •

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

TUP046

Low Frequency, Low Beta Cavity Performance Improvement Studies

527

P. Kolb, R.E. Laxdal, Z.Y. Yao
TRIUMF, Vancouver, Canada

In recent years, new discoveries such as N₂ doping and infusion lead to a significant increases in Q₀ and accelerating gradient for 1.3 GHz, β=1 elliptical cavities. To understand and to adapt these treatments for lower frequency, \beta < 1 cavities, two coaxial test cavities, one quarter-wave resonator (QWR) and one half-wave resonator (HWR), have been built and put through a systematic study of these new treatments to show the effectiveness of these treatments at different frequencies. These cavities are tested in their fundamental mode and several higher order modes to study the frequency dependence of new cavity treatments such as N₂ doping and infusion. Results of these studies are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP046

About •

paper received ※ 22 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)

TUP106

Mechanical Tuner for a 325 MHz Balloon Single Spoke Resonator

730

R.E. Laxdal, J.J. Keir, B. Matheson, N. Muller, Z.Y. Yao
TRIUMF, Vancouver, Canada

TRIUMF has designed, fabricated and tested the first balloon variant of the single spoke resonator at 325 MHz and β=0.3. TRIUMF has also designed and built a mechanical tuner as part of the development. The tuner employs a nutcracker lever pressing at the beam ports driven by a scissor jack. The scissor is actuated through a tube coupling to a warm ball-screw and servo-motor located outside the cryostat. The design and warm tests of the tuner will be presented.

Poster TUP106 [1.089 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP106

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)

THP047

Progress of TRIUMF Beta-SRF Facility for Novel SRF Materials

964

SUSP003

use link to see paper's listing under its alternate paper code

E. Thoeng
UBC & TRIUMF, Vancouver, British Columbia, Canada
R.A. Baartman, P. Kolb, R.E. Laxdal, B. Matheson, G. Morris, N. Muller, S. Saminathan
TRIUMF, Vancouver, Canada
T. Junginger
UVIC, Victoria, Canada

Funding: NSERC (Natural Sciences and Engineering Research Council of Canada)
SRF cavities made with bulk Nb have been the backbone of high-power modern linear accelerators. Demands for higher energy and more efficient linear accelerators, however, have strained the capabilities of bulk Nb close to its fundamental limit. Several routes have been proposed using thin film novel superconductors (e.g. Nb₃Sn), SIS multilayer, and N-doping. Beta-NMR techniques are more suitable for the characterization of Meissner state in these materials, due to the capability of soft-landing radioactive ions on the nanometer scale of London penetration depth, as compared to micrometer probe of the muSR technique. Upgrade of the existing beta-NQR beamline, combined with the capability of high parallel magnetic field (200 mT) are the scope of the beta-SRF facility which has been fully funded. All hardware required for the upgrade has also been procured. The status of the commissioning, which is currently in phase I, is reported here, together with the future schedule of phase II with the fully installed beta-SRF beamline. Finally, the detail layout of the completed beamline and sample requirements will be included in this paper which might be of interest of future users.

Poster THP047 [1.372 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP047

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)

FRCAA2

Balloon Single Spoke Resonator - A New Variant for Reduced Multipacting

Z.Y. Yao, R.E. Laxdal
TRIUMF, Vancouver, Canada

Spoke resonators have been widely proposed and optimized for various applications. Good performance has been demonstrated by many cavity tests. Accompanying the great progress, the adverse impact of strong multipacting (MP) is also noted, consistent with modern 3D simulations. This paper will discuss MP behaviors in the single spoke resonator (SSR). In particular a phenomenological theory is developed to highlight the details of the geometry that affect MP. The analysis leads to an optimized geometry of a single spoke resonator defined here as the ’balloon’ geometry. TRIUMF has designed, fabricated and tested the first balloon SSR at 325 MHz and β=0.3. Cold tests proved the principle of the balloon concept, the elimination of MP barriers around the operational gradient. This paper will also report the details of the mechanical and RF design, the fabrication steps and recent cold test results.

Slides FRCAA2 [19.831 MB]

Export •

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