SRF2015 - List of Authors (Laxdal, R.E.)

Paper	Title	Page
MOAA01	FRIB Project: Moving to Production Phase	1
	K. Saito, H. Ao, N.K. Bultman, E.E. Burkhardt, F. Casagrande, S. Chouhan, C. Compton, J.L. Crisp, K.D. Davidson, K. Elliott, F. Feyzi, A.D. Fox, P.E. Gibson, L. Hodges, K. Holland, G. Kiupel, S.M. Lidia, I.M. Malloch, D. Miller, S.J. Miller, D. Morris, D. Norton, J. Popielarski, L. Popielarski, A.P. Rauch, R.J. Rose, T. Russo, S. Shanab, M. Shuptar, S. Stark, G.J. Velianoff, D.R. Victory, J. Wei, T. Xu, T. Xu, Y. Yamazaki, Q. Zhao, Z. Zheng FRIB, East Lansing, Michigan, USA S.K. Chandrasekaran Fermilab, Batavia, Illinois, USA A. Facco INFN/LNL, Legnaro (PD), Italy K. Hosoyama, M. Masuzawa KEK, Ibaraki, Japan R.E. Laxdal TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada M.X. Xu IMP/CAS, Lanzhou, People's Republic of China
	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) is based upon a high power heavy ion driver linac under construction at Michigan State University under a cooperative agreement with the US DOE. The construction of conventional facilities already started in the summer, 2013, and the accelerator production began from the summer, 2014. FRIB will accelerate all the stable ion beams from proton to uranium beyond a beam energy of 200 MeV/u and up to a beam power of 400 kW to produce a great number of various rare isotopes using SRF linac. The FRIB SRF driver linac makes use of four kinds of SRF structures. Totally 332 two gap cavities and 48 cryomodules are needed. All SRF hardware components have been validated and are now moving to production. The SRF infrastructure also has been constructed in MSU campus. This talk will present FRIB project and challenges regarding SRF technologies. The status of SRF linac hardware validation and their production, SRF infrastructure status and plan shall be addressed. The information that can be relevant for future large scale proton/ion SRF linacs will also be provided.
	Slides MOAA01 [2.754 MB]
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MOPB050	Characterization of SRF Materials at the TRIUMF muSR Facility	205
	R.E. Laxdal, T.J. Buck, T. Junginger, P. Kolb, Y.Y. Ma, L. Yang, Z.Y. Yao TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada S.H. Abidi University of Toronto, Toronto, Ontario, Canada R. Kiefl UBC & TRIUMF, Vancouver, British Columbia, Canada
	MuSR is a powerful tool to probe local magnetism and hence can be used to diagnose flux penetration in Type-II superconductors. Samples produced at TRIUMF and with collaborators in both coin shaped and ellipsoidal geometries have been characterized by applying either transverse or parallel fields between 0 and 300mT and measuring flux entry as a function of applied field. Samples include Nb treated in standard ways including forming, chemistry, and heat treatments. Further, Nb samples have been doped with Nitrogen and coated with a 2 micron layer of Nb3Sn by collaborators from FNAL and Cornell respectively and measured in three field/geometry configurations. Analysis of the method in particular the effects of geometry and the role of pinning will be presented. Results of the measurements will be presented.
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MOPB051	Muon Spin Rotation on Treated Nb Samples in Parallel Field Geometry	210
	S. Gheidi UBC, Vancouver, B.C., Canada T.J. Buck, T. Junginger, R.E. Laxdal, G. Morris TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada M. Dehn TUM/Physik, Garching bei München, Germany R. Kiefl UBC & TRIUMF, Vancouver, British Columbia, Canada
	MuSR is a powerful tool to probe local magnetism and hence can be used to diagnose the entry of magnetic flux in superconductors. First measurements on SRF samples were done with an external DC field applied perpendicular to the sample1 (transverse geometry) with the muons applied to the sample face. Here the results are strongly impacted by demagnetization, pinning strength and edge effects. A new spectrometer has been developed to allow sample testing with a field varying from 0 to 300mT applied along the sample face (parallel geometry) analogous to rf fields in SRF resonators. The geometry is characterized by a small demagnetization factor reducing the impact of pinning and edge effects on field of first flux entry. The beamline installation and first results comparing transverse and parallel results will be presented. 1 Grassellino et al. Muon spin rotation studies of niobium for superconducting rf applications. Phys. Rev. ST Accel. Beams, 16:062002, Jun 2013.
	Poster MOPB051 [0.719 MB]
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MOPB071	Technology Readiness Levels Applied to Current SRF Accelerator Technology for ADS	276
	R. Edinger PAVAC, Richmond, B.C., Canada R.E. Laxdal, L. Yang TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	Accelerator Driven Systems (ADS) are comprised of high power accelerators supplying a proton beam to a reactor vessel. The reactor vessel could contain fuels such as used uranium nuclear fuels or Thorium. The proton beam will be used to produce Neutrons by spallation in the reactor vessel. Technology readiness levels (TRL’s) can be used to chart technology status with respect to end goal and as such can be used to outline a road map to complete an ADS system. TRL1 defines basic principles observed and reported, whereas TRL9 is defined as system ready for full scale deployment. SRF technology when applied to ADS reflects a mix of TRL levels since worldwide many SRF Accelerators are in operation. The paper will identify the building blocks of an ADS accelerator and analyze each for technical readiness for industrial scale deployment. The integrated ADS structure is far more complex than the individual systems, but the use of proven sub-systems allows to build SRF accelerators that could deliver the beam required. An analysis of the technical readiness of SRF technology for ADS will be presented.
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MOPB088	HOM Measurements on the ARIEL eLINAC Cryomodules	347
	P. Kolb, R.E. Laxdal, Y. Ma, Z.Y. Yao, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	The ARIEL eLINAC is a 50 MeV, 10 mA electron LINAC designed for the creation of rare isotopes via photo-fission. Future upgrade plans include the addition of a recirculating beam line to allow for either further energy increase of the beam beyond 50 MeV or to operate a free electron laser in an energy recovery mode. For both recirculating LINAC and ERL the higher order modes (HOM) have to be sufficiently suppressed to prevent beam-break-up. The design of the 1.3 GHz nine-cell cavity incorporated this requirement by including beam line absorbers on both ends of each cavity and an asymmetric beam pipe configuration on the cavity to allow trapped modes to propagate to the beam line absorbers. Measurements of the higher order modes on the completed injector cryomodule and the first cavity in the accelerating cryomodules will be shown and compared to simulations.
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MOPB089	1.3 GHz Cavity Test Program for ARIEL	350
	P. Kolb, P.R. Harmer, J.J. Keir, D. Kishi, D. Lang, R.E. Laxdal, H. Liu, Y. Ma, T. Shishido, B.S. Waraich, Z.Y. Yao, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada E. Bourassa, R.S. Orr, D. Trischuk University of Toronto, Toronto, Ontario, Canada T. Shishido KEK, Ibaraki, Japan
	The ARIEL eLINAC is a 50 MeV 10 mA electron LINAC. Once finished, five cavities will each provide 10MV of effective accelerating voltage. At the present time two cavities have been installed and successfully accelerated been above specifications of 10 MV/m at a Q0 of 10¹⁰. The next cavities are already in the pipeline and being processed. In addition, one additional cavity has been produced for our collaboration with VECC, India. This cavity has been tested and installed in a cryomodule identical to the eLINAC injector cryomodule. New developments for single cell testing at TRIUMF are a T-mapping system developed in collaboration with UoT and vertical EP for single cells. The progress of the performance after each treatment step has been measured and will be shown. measured and will be shown.
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MOPB096	Vertical Electro-Polishing at TRIUMF	378
	J.J. Keir, P.R. Harmer, D. Lang, R.E. Laxdal, T. Shishido, R. Smith TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada T. Shishido KEK, Ibaraki, Japan
	A setup for electropolishing of a superconducting niobium single-cell cavity has been installed at TRIUMF. A vertical method was selected to make the setup compact. To increase removal speed at the equator and remove hydrogen bubbles at the iris surface, 4 cathode paddles were rotated in the cavity cell during electropolishing. We will report on our first electropolishing result.
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TUAA02	Commissioning of the SRF Linac for ARIEL	457
	V. Zvyagintsev, Z.T. Ang, T. Au, S. Calic, K. Fong, P.R. Harmer, B. Jakovljevic, J.J. Keir, D. Kishi, P. Kolb, S.R. Koscielniak, A. Koveshnikov, C. Laforge, D. Lang, M.P. Laverty, R.E. Laxdal, Y. Ma, A.K. Mitra, N. Muller, R.R. Nagimov, W.R. Rawnsley, R.W. Shanks, R. Smith, B.S. Waraich, L. Yang, Z.Y. Yao, Q. Zheng TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	This paper is reporting commissioning results for the SRF linac of ARIEL facility at TRIUMF. The paper is focused on the SRF challenges: cavity design and performance, ancillaries design and preparation, cryomodule design and performance, RF system and final beam test results.
	Slides TUAA02 [4.004 MB]
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TUPB041	Testing Nb3Sn Coating Using muSR	651
	R.E. Laxdal, T.J. Buck TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada S. Gheidi UBC, Vancouver, B.C., Canada R. Kiefl UBC & TRIUMF, Vancouver, British Columbia, Canada M. Liepe, S. Posen Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	The SRF group at TRIUMF has tested samples relevant for SRF application since 2010 using the TRIUMF μSR facility. In this study collaborators at Cornell coat a Nb coin and a Nb ellipsoid sample with Nb3Sn for characterization using μSR at TRIUMF. Field of first flux entry measurements are performed at M20 on both samples. Measurements include the vortex nucleation field Hnucleate and Tc of both Nb3Sn and Nb. Interestingly the Nb3Sn increases the vortex nucleation field at 2K over standard Nb samples.
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TUPB096	Mechanical Damper Study for ISAC-II Quarter Wave Resonators	832
	L. Yang, R.E. Laxdal, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	ISAC-II superconducting quarter wave resonators are equipped with mechanical dampers to supress mechanical oscillations of the cavity structure. The study has been carried out to optimize the damper efficiency.
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TUPB103	Cryomodule Protection for ARIEL e-Linac	861
	Z.Y. Yao, R.E. Laxdal, W.R. Rawnsley, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	The e-Linac cryomodules require high RF power, cryogenics, ultra-high vacuum, and precise mechanical adjustment. They require protection against of failures, like quench in the cavity, bad vacuum or multipacting in power couplers, low liquid helium level or high temperatures. The protection unit should stop RF power in the cryomodule in case of the listed failures. A Interlock Box is developed to implement protection function for the cryomodule. The paper will describe the design of Interlock Box for e-Linac cryomodule protection. As quench protection required, quench evolution analysis with RF transient analysis is investigated. The details of quench detection for e-Linac will also be reported.
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TUPB114	Transient Study of Beam Loading and Feed-Forward LLRF Control of ARIEL Superconducting RF e-LINAC	902
	E. Thoeng UBC & TRIUMF, Vancouver, British Columbia, Canada R.E. Laxdal TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	ARIEL e-LINAC is a ½ MW-class SRF accelerator operated at 10 mA of average current. In the initial commissioning, e-LINAC will be tested with increasing duty factors from 0.1% up to CW mode. During the pulsed mode operation, beam loading causes cavity gradient fluctuation and therefore transient behaviour of SRF Cavity gradient needs to be studied in order to determine how the Low-level RF (LLRF) should be implemented. Performance of LLRF control system with and without non-adaptive feed-forward are simulated to determine the resulting beam energy spread and experimental measurements are proposed to measure the increase of beam size due to beam loading.
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TUPB120	The Cryogenic Infrastructure for SRF Testing at TRIUMF	919
	R.R. Nagimov, P.R. Harmer, D. Kishi, A. Koveshnikov, R.E. Laxdal, H. Liu, N. Muller TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	Funding: Canada Foundation for Innovation, British Columbia Knowledge Development Fund, and National Research Council Canada. At the moment TRIUMF operates one superconductive radio-frequency (SRF) accelerator and is building the second one. The superconducting heavy ion linear accelerator of the Isotope Separation and Acceleration (ISAC) facility utilizes medium beta quarter wave cavities cooled down to 4 K. The Advanced Rare IsotopE Laboratory (ARIEL) is a major expansion of the ISAC facility. ARIEL SRF electron linear accelerator (e-linac) operates nine-cell TESLA type cavities at 2 K. Both accelerators have dedicated cryogenic systems including liquid helium plants and distribution systems. In addition to accelerator cryogenic support, ISAC cryoplant provides liquid helium for the SRF testing facility at both 4 K and 2 K temperatures. TRIUMF’s SRF development involves both SRF testing facility and accelerators cryogenic support systems. This paper presents the details of the SRF testing cryogenic systems as well as recent commissioning results of the new e-linac cryogenic system.
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WEA1A03	Medium Field Q-Slope in Low Beta Resonators
	Z.Y. Yao, P. Kolb, R.E. Laxdal TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	A significant issue in low beta resonators is medium field Q-slope (MFQS) at 4K that in some cases has resulted in projects choosing to operate low frequency cavities at 2K. Recent measurements have been done on QWR (80MHz) and HWR (160MHz) cavities at TRIUMF to study the MFQS of Low Beta Resonators. Quality factor data taken in cooling from 4K to 2K is used to separate the rf surface resistance into BCS and residual components for different surface treatments. These measurements shed light on the mechanisms behind the field dependence in the rf surface resistance.
	Slides WEA1A03 [1.982 MB]
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THPB021	Balloon Variant of Single Spoke Resonator	1110
	Z.Y. Yao, R.E. Laxdal, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, 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 by recent test reports, consistent with modern 3D simulations. This paper will discuss MP behaviors in the single spoke resonator. 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’. A 325MHz β=0.3 single spoke resonator based on 'balloon' concept is under development by the RISP-TRIUMF Collaboration. The RF and mechanical design of this cavity will also be reported.
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THPB043	Alternative Fabrication Methods for the ARIEL e-Linac SRF Separator Cavity	1185
	D.W. Storey Victoria University, Victoria, B.C., Canada R.E. Laxdal, N. Muller TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	The ARIEL e-Linac RF deflecting cavity is a 650 MHz superconducting deflecting mode cavity that will allow simultaneous beam delivery to both the Rare Isotope Beam program and an Energy Recovery Linac. The cavity will be operated at 4 K and with deflecting voltages of up 0.6 MV, resulting in a dissipated RF power of less than 1 W. Due to the modest performance requirements, alternative methods are being employed for the fabrication of this cavity. These include fabricating the entire cavity from reactor grade Niobium and welding the cavity using tungsten inert gas (TIG) welding in a high purity Argon environment. A post purification heat treatment will be performed in an RF induction oven to increase the cavity performance.
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THPB044	A Superconducting RF Deflecting Cavity for the ARIEL e-Linac Separator	1187
	D.W. Storey Victoria University, Victoria, B.C., Canada R.E. Laxdal, L. Merminga, B.S. Waraich, Z.Y. Yao, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	A 650 MHz SRF deflecting mode cavity has been designed for the ARIEL e-Linac to separate interleaved beams heading towards either Rare Ion Beam production or a recirculation loop for energy recovery, allowing the e-Linac to provide beam delivery to multiple users simultaneously. The cavity geometry has been optimized for the ARIEL specifications, resulting in a very compact cavity with high shunt impedance and low dissipated power. Analyses have been performed on the susceptibility to multipacting, input coupling considering beam loading and microphonics, and extensive studies into the damping of transverse and longitudinal higher order modes. The pressure sensitivity, frequency tuning, and thermal behaviour have also been studied using ANSYS. The cavity design resulting from these considerations will be discussed here.
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THPB103	High Power Coupler Test for ARIEL SC Cavities	1390
	Y. Ma, P.R. Harmer, D. Lang, R.E. Laxdal, B.S. Waraich, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	TRIUMF ARIEL[1](The Advanced Rare Isotope Laboratory) project employs five 1.3 GHz 9-cell superconducting elliptical cavities[2] for acceleration of 10 mA electron beam up to energy of 50 MeV. 100 kW CW RF power will be delivered into each cavity by means of pair of Power Couplers: 50 kW per each coupler. Before installing the power couplers with the cavities, they have to be assembled on Power Coupler Test Stand(PCTS) and conditioned with a 30 kW IOT. Six couplers have been conditioned at room temperature and four of them have been installed to the cavities and tested during beam commissioning. Test results of the power couplers will be described and discussed in this paper. #mayanyun@triumf.ca
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THPB115	TRIUMF's Injector and Accelerator Cryomodules	1409
	N. Muller, P.R. Harmer, J.J. Keir, D. Kishi, P. Kolb, A. Koveshnikov, C. Laforge, D. Lang, R.E. Laxdal, Y. Ma, A.K. Mitra, R.R. Nagimov, R. Smith, B.S. Waraich, L. Yang, Z.Y. Yao, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	TRIUMF's ARIEL project includes a 50 MeV-10mA electron linear accelerator (e-Linac) using 1.3 GHz superconducting technology. The accelerator consists of three cryomodules; an injector cryomodule with one cavity and two accelerating cryomodules with two cavities each. One injector and one accelerator have been assembled and commissioned at TRIUMF with a second injector cryomodule being assembled for VECC in Kolkata. Both Injector and Accelerator cryomodules utilize a top-loaded cold mass design contained in a box-type cryomodule; design and early test results of both cryomodules are presented.
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Paper

Title

Page

FRIB Project: Moving to Production Phase

1

K. Saito, H. Ao, N.K. Bultman, E.E. Burkhardt, F. Casagrande, S. Chouhan, C. Compton, J.L. Crisp, K.D. Davidson, K. Elliott, F. Feyzi, A.D. Fox, P.E. Gibson, L. Hodges, K. Holland, G. Kiupel, S.M. Lidia, I.M. Malloch, D. Miller, S.J. Miller, D. Morris, D. Norton, J. Popielarski, L. Popielarski, A.P. Rauch, R.J. Rose, T. Russo, S. Shanab, M. Shuptar, S. Stark, G.J. Velianoff, D.R. Victory, J. Wei, T. Xu, T. Xu, Y. Yamazaki, Q. Zhao, Z. Zheng
FRIB, East Lansing, Michigan, USA
S.K. Chandrasekaran
Fermilab, Batavia, Illinois, USA
A. Facco
INFN/LNL, Legnaro (PD), Italy
K. Hosoyama, M. Masuzawa
KEK, Ibaraki, Japan
R.E. Laxdal
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
M.X. Xu
IMP/CAS, Lanzhou, People's Republic of China

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) is based upon a high power heavy ion driver linac under construction at Michigan State University under a cooperative agreement with the US DOE. The construction of conventional facilities already started in the summer, 2013, and the accelerator production began from the summer, 2014. FRIB will accelerate all the stable ion beams from proton to uranium beyond a beam energy of 200 MeV/u and up to a beam power of 400 kW to produce a great number of various rare isotopes using SRF linac. The FRIB SRF driver linac makes use of four kinds of SRF structures. Totally 332 two gap cavities and 48 cryomodules are needed. All SRF hardware components have been validated and are now moving to production. The SRF infrastructure also has been constructed in MSU campus. This talk will present FRIB project and challenges regarding SRF technologies. The status of SRF linac hardware validation and their production, SRF infrastructure status and plan shall be addressed. The information that can be relevant for future large scale proton/ion SRF linacs will also be provided.

Slides MOAA01 [2.754 MB]

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MOPB050

Characterization of SRF Materials at the TRIUMF muSR Facility

205

R.E. Laxdal, T.J. Buck, T. Junginger, P. Kolb, Y.Y. Ma, L. Yang, Z.Y. Yao
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
S.H. Abidi
University of Toronto, Toronto, Ontario, Canada
R. Kiefl
UBC & TRIUMF, Vancouver, British Columbia, Canada

MuSR is a powerful tool to probe local magnetism and hence can be used to diagnose flux penetration in Type-II superconductors. Samples produced at TRIUMF and with collaborators in both coin shaped and ellipsoidal geometries have been characterized by applying either transverse or parallel fields between 0 and 300mT and measuring flux entry as a function of applied field. Samples include Nb treated in standard ways including forming, chemistry, and heat treatments. Further, Nb samples have been doped with Nitrogen and coated with a 2 micron layer of Nb3Sn by collaborators from FNAL and Cornell respectively and measured in three field/geometry configurations. Analysis of the method in particular the effects of geometry and the role of pinning will be presented. Results of the measurements will be presented.

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MOPB051

Muon Spin Rotation on Treated Nb Samples in Parallel Field Geometry

210

S. Gheidi
UBC, Vancouver, B.C., Canada
T.J. Buck, T. Junginger, R.E. Laxdal, G. Morris
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
M. Dehn
TUM/Physik, Garching bei München, Germany
R. Kiefl
UBC & TRIUMF, Vancouver, British Columbia, Canada

MuSR is a powerful tool to probe local magnetism and hence can be used to diagnose the entry of magnetic flux in superconductors. First measurements on SRF samples were done with an external DC field applied perpendicular to the sample1 (transverse geometry) with the muons applied to the sample face. Here the results are strongly impacted by demagnetization, pinning strength and edge effects. A new spectrometer has been developed to allow sample testing with a field varying from 0 to 300mT applied along the sample face (parallel geometry) analogous to rf fields in SRF resonators. The geometry is characterized by a small demagnetization factor reducing the impact of pinning and edge effects on field of first flux entry. The beamline installation and first results comparing transverse and parallel results will be presented.
1 Grassellino et al. Muon spin rotation studies of niobium for superconducting rf applications.
Phys. Rev. ST Accel. Beams, 16:062002, Jun 2013.

Poster MOPB051 [0.719 MB]

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MOPB071

Technology Readiness Levels Applied to Current SRF Accelerator Technology for ADS

276

R. Edinger
PAVAC, Richmond, B.C., Canada
R.E. Laxdal, L. Yang
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

Accelerator Driven Systems (ADS) are comprised of high power accelerators supplying a proton beam to a reactor vessel. The reactor vessel could contain fuels such as used uranium nuclear fuels or Thorium. The proton beam will be used to produce Neutrons by spallation in the reactor vessel. Technology readiness levels (TRL’s) can be used to chart technology status with respect to end goal and as such can be used to outline a road map to complete an ADS system. TRL1 defines basic principles observed and reported, whereas TRL9 is defined as system ready for full scale deployment. SRF technology when applied to ADS reflects a mix of TRL levels since worldwide many SRF Accelerators are in operation. The paper will identify the building blocks of an ADS accelerator and analyze each for technical readiness for industrial scale deployment. The integrated ADS structure is far more complex than the individual systems, but the use of proven sub-systems allows to build SRF accelerators that could deliver the beam required. An analysis of the technical readiness of SRF technology for ADS will be presented.

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MOPB088

HOM Measurements on the ARIEL eLINAC Cryomodules

347

P. Kolb, R.E. Laxdal, Y. Ma, Z.Y. Yao, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

The ARIEL eLINAC is a 50 MeV, 10 mA electron LINAC designed for the creation of rare isotopes via photo-fission. Future upgrade plans include the addition of a recirculating beam line to allow for either further energy increase of the beam beyond 50 MeV or to operate a free electron laser in an energy recovery mode. For both recirculating LINAC and ERL the higher order modes (HOM) have to be sufficiently suppressed to prevent beam-break-up. The design of the 1.3 GHz nine-cell cavity incorporated this requirement by including beam line absorbers on both ends of each cavity and an asymmetric beam pipe configuration on the cavity to allow trapped modes to propagate to the beam line absorbers. Measurements of the higher order modes on the completed injector cryomodule and the first cavity in the accelerating cryomodules will be shown and compared to simulations.

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MOPB089

1.3 GHz Cavity Test Program for ARIEL

350

P. Kolb, P.R. Harmer, J.J. Keir, D. Kishi, D. Lang, R.E. Laxdal, H. Liu, Y. Ma, T. Shishido, B.S. Waraich, Z.Y. Yao, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
E. Bourassa, R.S. Orr, D. Trischuk
University of Toronto, Toronto, Ontario, Canada
T. Shishido
KEK, Ibaraki, Japan

The ARIEL eLINAC is a 50 MeV 10 mA electron LINAC. Once finished, five cavities will each provide 10MV of effective accelerating voltage. At the present time two cavities have been installed and successfully accelerated been above specifications of 10 MV/m at a Q0 of 10¹⁰. The next cavities are already in the pipeline and being processed. In addition, one additional cavity has been produced for our collaboration with VECC, India. This cavity has been tested and installed in a cryomodule identical to the eLINAC injector cryomodule. New developments for single cell testing at TRIUMF are a T-mapping system developed in collaboration with UoT and vertical EP for single cells. The progress of the performance after each treatment step has been measured and will be shown. measured and will be shown.

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MOPB096

Vertical Electro-Polishing at TRIUMF

378

J.J. Keir, P.R. Harmer, D. Lang, R.E. Laxdal, T. Shishido, R. Smith
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
T. Shishido
KEK, Ibaraki, Japan

A setup for electropolishing of a superconducting niobium single-cell cavity has been installed at TRIUMF. A vertical method was selected to make the setup compact. To increase removal speed at the equator and remove hydrogen bubbles at the iris surface, 4 cathode paddles were rotated in the cavity cell during electropolishing. We will report on our first electropolishing result.

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TUAA02

Commissioning of the SRF Linac for ARIEL

457

V. Zvyagintsev, Z.T. Ang, T. Au, S. Calic, K. Fong, P.R. Harmer, B. Jakovljevic, J.J. Keir, D. Kishi, P. Kolb, S.R. Koscielniak, A. Koveshnikov, C. Laforge, D. Lang, M.P. Laverty, R.E. Laxdal, Y. Ma, A.K. Mitra, N. Muller, R.R. Nagimov, W.R. Rawnsley, R.W. Shanks, R. Smith, B.S. Waraich, L. Yang, Z.Y. Yao, Q. Zheng
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

This paper is reporting commissioning results for the SRF linac of ARIEL facility at TRIUMF. The paper is focused on the SRF challenges: cavity design and performance, ancillaries design and preparation, cryomodule design and performance, RF system and final beam test results.

Slides TUAA02 [4.004 MB]

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TUPB041

Testing Nb3Sn Coating Using muSR

651

R.E. Laxdal, T.J. Buck
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
S. Gheidi
UBC, Vancouver, B.C., Canada
R. Kiefl
UBC & TRIUMF, Vancouver, British Columbia, Canada
M. Liepe, S. Posen
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

The SRF group at TRIUMF has tested samples relevant for SRF application since 2010 using the TRIUMF μSR facility. In this study collaborators at Cornell coat a Nb coin and a Nb ellipsoid sample with Nb3Sn for characterization using μSR at TRIUMF. Field of first flux entry measurements are performed at M20 on both samples. Measurements include the vortex nucleation field Hnucleate and Tc of both Nb3Sn and Nb. Interestingly the Nb3Sn increases the vortex nucleation field at 2K over standard Nb samples.

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TUPB096

Mechanical Damper Study for ISAC-II Quarter Wave Resonators

832

L. Yang, R.E. Laxdal, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

ISAC-II superconducting quarter wave resonators are equipped with mechanical dampers to supress mechanical oscillations of the cavity structure. The study has been carried out to optimize the damper efficiency.

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TUPB103

Cryomodule Protection for ARIEL e-Linac

861

Z.Y. Yao, R.E. Laxdal, W.R. Rawnsley, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

The e-Linac cryomodules require high RF power, cryogenics, ultra-high vacuum, and precise mechanical adjustment. They require protection against of failures, like quench in the cavity, bad vacuum or multipacting in power couplers, low liquid helium level or high temperatures. The protection unit should stop RF power in the cryomodule in case of the listed failures. A Interlock Box is developed to implement protection function for the cryomodule. The paper will describe the design of Interlock Box for e-Linac cryomodule protection. As quench protection required, quench evolution analysis with RF transient analysis is investigated. The details of quench detection for e-Linac will also be reported.

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TUPB114

Transient Study of Beam Loading and Feed-Forward LLRF Control of ARIEL Superconducting RF e-LINAC

902

E. Thoeng
UBC & TRIUMF, Vancouver, British Columbia, Canada
R.E. Laxdal
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

ARIEL e-LINAC is a ½ MW-class SRF accelerator operated at 10 mA of average current. In the initial commissioning, e-LINAC will be tested with increasing duty factors from 0.1% up to CW mode. During the pulsed mode operation, beam loading causes cavity gradient fluctuation and therefore transient behaviour of SRF Cavity gradient needs to be studied in order to determine how the Low-level RF (LLRF) should be implemented. Performance of LLRF control system with and without non-adaptive feed-forward are simulated to determine the resulting beam energy spread and experimental measurements are proposed to measure the increase of beam size due to beam loading.

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TUPB120

The Cryogenic Infrastructure for SRF Testing at TRIUMF

919

R.R. Nagimov, P.R. Harmer, D. Kishi, A. Koveshnikov, R.E. Laxdal, H. Liu, N. Muller
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

Funding: Canada Foundation for Innovation, British Columbia Knowledge Development Fund, and National Research Council Canada.
At the moment TRIUMF operates one superconductive radio-frequency (SRF) accelerator and is building the second one. The superconducting heavy ion linear accelerator of the Isotope Separation and Acceleration (ISAC) facility utilizes medium beta quarter wave cavities cooled down to 4 K. The Advanced Rare IsotopE Laboratory (ARIEL) is a major expansion of the ISAC facility. ARIEL SRF electron linear accelerator (e-linac) operates nine-cell TESLA type cavities at 2 K. Both accelerators have dedicated cryogenic systems including liquid helium plants and distribution systems. In addition to accelerator cryogenic support, ISAC cryoplant provides liquid helium for the SRF testing facility at both 4 K and 2 K temperatures. TRIUMF’s SRF development involves both SRF testing facility and accelerators cryogenic support systems. This paper presents the details of the SRF testing cryogenic systems as well as recent commissioning results of the new e-linac cryogenic system.

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WEA1A03

Medium Field Q-Slope in Low Beta Resonators

Z.Y. Yao, P. Kolb, R.E. Laxdal
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

A significant issue in low beta resonators is medium field Q-slope (MFQS) at 4K that in some cases has resulted in projects choosing to operate low frequency cavities at 2K. Recent measurements have been done on QWR (80MHz) and HWR (160MHz) cavities at TRIUMF to study the MFQS of Low Beta Resonators. Quality factor data taken in cooling from 4K to 2K is used to separate the rf surface resistance into BCS and residual components for different surface treatments. These measurements shed light on the mechanisms behind the field dependence in the rf surface resistance.

Slides WEA1A03 [1.982 MB]

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THPB021

Balloon Variant of Single Spoke Resonator

1110

Z.Y. Yao, R.E. Laxdal, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, 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 by recent test reports, consistent with modern 3D simulations. This paper will discuss MP behaviors in the single spoke resonator. 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’. A 325MHz β=0.3 single spoke resonator based on 'balloon' concept is under development by the RISP-TRIUMF Collaboration. The RF and mechanical design of this cavity will also be reported.

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THPB043

Alternative Fabrication Methods for the ARIEL e-Linac SRF Separator Cavity

1185

D.W. Storey
Victoria University, Victoria, B.C., Canada
R.E. Laxdal, N. Muller
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

The ARIEL e-Linac RF deflecting cavity is a 650 MHz superconducting deflecting mode cavity that will allow simultaneous beam delivery to both the Rare Isotope Beam program and an Energy Recovery Linac. The cavity will be operated at 4 K and with deflecting voltages of up 0.6 MV, resulting in a dissipated RF power of less than 1 W. Due to the modest performance requirements, alternative methods are being employed for the fabrication of this cavity. These include fabricating the entire cavity from reactor grade Niobium and welding the cavity using tungsten inert gas (TIG) welding in a high purity Argon environment. A post purification heat treatment will be performed in an RF induction oven to increase the cavity performance.

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THPB044

A Superconducting RF Deflecting Cavity for the ARIEL e-Linac Separator

1187

D.W. Storey
Victoria University, Victoria, B.C., Canada
R.E. Laxdal, L. Merminga, B.S. Waraich, Z.Y. Yao, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

A 650 MHz SRF deflecting mode cavity has been designed for the ARIEL e-Linac to separate interleaved beams heading towards either Rare Ion Beam production or a recirculation loop for energy recovery, allowing the e-Linac to provide beam delivery to multiple users simultaneously. The cavity geometry has been optimized for the ARIEL specifications, resulting in a very compact cavity with high shunt impedance and low dissipated power. Analyses have been performed on the susceptibility to multipacting, input coupling considering beam loading and microphonics, and extensive studies into the damping of transverse and longitudinal higher order modes. The pressure sensitivity, frequency tuning, and thermal behaviour have also been studied using ANSYS. The cavity design resulting from these considerations will be discussed here.

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THPB103

High Power Coupler Test for ARIEL SC Cavities

1390

Y. Ma, P.R. Harmer, D. Lang, R.E. Laxdal, B.S. Waraich, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

TRIUMF ARIEL[1](The Advanced Rare Isotope Laboratory) project employs five 1.3 GHz 9-cell superconducting elliptical cavities[2] for acceleration of 10 mA electron beam up to energy of 50 MeV. 100 kW CW RF power will be delivered into each cavity by means of pair of Power Couplers: 50 kW per each coupler. Before installing the power couplers with the cavities, they have to be assembled on Power Coupler Test Stand(PCTS) and conditioned with a 30 kW IOT. Six couplers have been conditioned at room temperature and four of them have been installed to the cavities and tested during beam commissioning. Test results of the power couplers will be described and discussed in this paper.
#mayanyun@triumf.ca

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THPB115

TRIUMF's Injector and Accelerator Cryomodules

1409

N. Muller, P.R. Harmer, J.J. Keir, D. Kishi, P. Kolb, A. Koveshnikov, C. Laforge, D. Lang, R.E. Laxdal, Y. Ma, A.K. Mitra, R.R. Nagimov, R. Smith, B.S. Waraich, L. Yang, Z.Y. Yao, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

TRIUMF's ARIEL project includes a 50 MeV-10mA electron linear accelerator (e-Linac) using 1.3 GHz superconducting technology. The accelerator consists of three cryomodules; an injector cryomodule with one cavity and two accelerating cryomodules with two cavities each. One injector and one accelerator have been assembled and commissioned at TRIUMF with a second injector cryomodule being assembled for VECC in Kolkata. Both Injector and Accelerator cryomodules utilize a top-loaded cold mass design contained in a box-type cryomodule; design and early test results of both cryomodules are presented.

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