SRF2015 - List of Authors (Yao, Z.Y.)

Paper	Title	Page
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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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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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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TUPB072	Report of Vertical Test of the β=0.12 Half-Wave Resonator at RISP	747
	G.-T. Park, H.J. Cha, H. Kim, W.K. Kim IBS, Daejeon, Republic of Korea Z.Y. Yao TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	β=0.12, f=162.5 MHz half-wave resonator for Rare Isotope Science Project (RISP) was recently tested at TRIUMF. We briefly report the vertical test result: At 2K, the cavity achieved Q₀=2·10⁹ at E_acc=6.4 MV/m and the performance was limited at E_acc=7.8 MV/m by intense field emission. The surface processing was standard: 120 micron buffered chemical polishing followed by high pressure rinsing. After first cold test, 120C baking was done and the corresponding result was also obtained.
	Poster TUPB072 [0.414 MB]
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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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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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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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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

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.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

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.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

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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reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

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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TUPB072

Report of Vertical Test of the β=0.12 Half-Wave Resonator at RISP

747

G.-T. Park, H.J. Cha, H. Kim, W.K. Kim
IBS, Daejeon, Republic of Korea
Z.Y. Yao
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

β=0.12, f=162.5 MHz half-wave resonator for Rare Isotope Science Project (RISP) was recently tested at TRIUMF. We briefly report the vertical test result: At 2K, the cavity achieved Q₀=2·10⁹ at E_acc=6.4 MV/m and the performance was limited at E_acc=7.8 MV/m by intense field emission. The surface processing was standard: 120 micron buffered chemical polishing followed by high pressure rinsing. After first cold test, 120C baking was done and the corresponding result was also obtained.

Poster TUPB072 [0.414 MB]

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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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reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

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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reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

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.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

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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