LINAC2018 - List of Keywords (accelerating-gradient)

Paper	Title	Other Keywords	Page
TUPO049	Nitrogen Doping Study With 1.3 GHz Single Cell Superconducting Cavities	cavity, vacuum, niobium, superconducting-cavity	442
	S. Chen, M. Chen, L.W. Feng, J.K. Hao, L. Lin, K.X. Liu, S.W. Quan, F. Wang, F. Zhu PKU, Beijing, People’s Republic of China
	Nitrogen doping studies were carried out at Peking University. A series of 1.3 GHz single cell cavities fabricated with OTIC large grain niobium material were annealed and doped in the furnace of Peking University, and electropolished by a simple EP device. Light doping recipe and heavy doping recipe are both adopted for comparison. The results and analysis are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO049
About •	paper received ※ 12 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPO065	Improvement of Cavity Performance by Nitrogen Doping at KEK	cavity, ECR, SRF, solenoid	480
	T. Okada, Y. Hori, E. Kako, T. Konomi, H. Sakai, K. Umemori, Y. Yamamoto Sokendai, Ibaraki, Japan T. Dohmae, Y. Hori, E. Kako, T. Konomi, T. Saeki, T. Saeki, H. Sakai, K. Umemori, Y. Yamamoto KEK, Ibaraki, Japan J. Kamiya JAEA/J-PARC, Tokai-mura, Japan S. Kurosawa, K. Takeishi JAEA, Ibaraki-ken, Japan
	Nitrogen doping experiments in single-cell and 3-cell niobium cavities were carried out at KEK. After annealing at 800 deg C for 3 hours, pure nitrogen gas with a pressure of 3 Pa for 20 minutes and 3 minutes were introduced for doping in a furnace in J-PARC, respectively. Removing surface in 5 um and 20 um by electropolishing were performed prior to the vertical tests, respectively. Increases of a quality factor at 2K and reduction of the BCS resistance with respect to an accelerating gradient were observed in both cavities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO065
About •	paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPO076	An Innovative Nb3Sn Film Approach and Its Potential for SRF Applications	cavity, SRF, site, cathode	513
	E.Z. Barzi, D. Turrioni, C. Ciaccia Fermilab, Batavia, Illinois, USA G.V. Eremeev, R.L. Geng, R.A. Rimmer, A-M. Valente-Feliciano JLab, Newport News, Virginia, USA S. Falletta Politecnico di Torino, Torino, Italy H. Hayano, T. Saeki KEK, Ibaraki, Japan H. Ito Sokendai, Ibaraki, Japan A. Kikuchi NIMS, Tsukuba, Ibaraki, Japan
	Funding: Work supported by U.S. DOE contract No. DE-AC02-07CH11359 A novel electro-chemical technique to produce Nb3Sn films on Nb substrates was developed and optimized at Fermilab. The Nb3Sn phase is obtained in a two-electrode cell, by electrodeposition from aqueous solutions of Sn layers and Cu intermediate layers onto Nb substrates. Subsequent thermal treatments in inert atmosphere are realized at a maximum temperature of 700°C to obtain the Nb3Sn superconducting phase. Several superconduct-ing Nb3Sn films were obtained on Nb substrates by study-ing and optimizing most parameters of the electro-plating process. Samples were characterized at Fermilab, NIMS, KEK and JLAB, including EPMA analyses, DC and in-ductive tests of critical temperature Tc0, and lower critical field Hc1(4.2 K) by SQUID. In parallel to sample devel-opment and fabrication at FNAL, at JLAB and KEK effort was put into etching and electro-polishing techniques adequate to remove the Cu and bronze phases from the samples’ outer surface. This is necessary prior to meas-urements at JLAB of the surface impedance of flat sam-ples in a setup that make use of an RF host cavity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO076
About •	paper received ※ 21 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPO113	Beam Dynamics Studies Through Dielectric THz Accelerating Structures	GUI, simulation, vacuum, linac	569
	R. Apsimon, G. Burt, A.L. Healy, S.P. Jamison Cockcroft Institute, Lancaster University, Lancaster, United Kingdom R.B. Appleby, E.J.H. Smith UMAN, Manchester, United Kingdom A. Latina CERN, Geneva, Switzerland
	As conventional RF accelerating schemes approach the physical limit of accelerating gradient, the accelerator community is increasingly looking at novel accelerating techniques to overcome these limitations. Moving from the RF to the THz frequency range, higher acceleration gradients of high energy beams can be achieved in compact structures. Beam dynamics studies are crucial as part of the design of novel accelerating structures to maximise the output beam current as well as the accelerating gradient. In this paper we present beam dynamics simulations through dielectric lined waveguide structures using novel techniques to simulate broadband signals for particle tracking studies in RF-Track. The beam parameters through the structure are optimised and we study the dynamics of general broadband accelerating structures.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO113
About •	paper received ※ 13 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPO066	First High Power Test of the ESS High Beta Elliptical Cavity	cavity, SRF, linac, flattop	841
	H. Li, L. Hermansson, M. Jobs, R.J.M.Y. Ruber, R. Santiago Kern Uppsala University, Uppsala, Sweden G. Devanz, T. Hamelin CEA/DSM/IRFU, France
	ESS, the European Spallation Source, will adopt elliptical multi-cell superconducting cavities with a beta value of 0.86 to accelerate the proton beam up to 2 GeV at the last section of the linac. A 5-cell high-beta cavity for ESS project was tested with high power at FREIA Laboratory. A pulse mode test stand based on a self-excited loop was used in this test. The qualification of the cavity package involved a 5-cell elliptical cavity, a fundamental power coupler, a cold tuning system, LLRF system and a RF station. These tests represented an important verification before the series production. This paper presents the test configuration, RF conditioning history, first high power performance and experience of this cavity package.
	Slides THPO066 [1.437 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO066
About •	paper received ※ 14 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPO072	Cryogenic Tests of the Superconducting β=0.069 CH-cavities for the HELIAC-project	cavity, linac, heavy-ion, cryogenics	855
	M. Basten, M. Busch, H. Podlech, M. Schwarz IAP, Frankfurt am Main, Germany K. Aulenbacher, W.A. Barth, F.D. Dziuba, V. Gettmann, T. Kürzeder, M. Miski-Oglu HIM, Mainz, Germany W.A. Barth, M. Heilmann, S. Yaramyshev GSI, Darmstadt, Germany
	In the future the existing UNILAC (UNIversal Linear Accelerator) at GSI will be most exclusively used as an injector for FAIR to provide short pulse high intensity heavy ion beams at low repetition rates [Barth3]. A new superconducting (sc) continuous wave (cw) high intensity heavy ion Linac should provide ion beams with max. duty factor above the coulomb barrier for the Super Heavy Element (SHE) program at GSI. The fundamental Linac design comprises a low energy beam transport (LEBT)-section followed by a sc Drift Tube Linac (DTL) consisting of sc Crossbar-H-mode (CH) structures for acceleration up to 7.3 MeV/u []. After the successful test and commissioning of the first demonstrator section with heavy ion beam from the HLI in 2017 [], the next two sc CH-structures have been constructed and the first one has been extensively tested at cryogenic temperatures at the Institute for Applied Physics (IAP) at Goethe University Frankfurt (GUF). The results of the final cold test of the first CH-structure as well as the next steps realizing a new sc cw heavy ion LINAC at GSI will be presented. []W. Barth et al., "Further investigations for a superconducting cw-Linac at GSI" [**]W. Barth et al., "First high intensity heavy ion beam tests with a superconducting multi gap CH-cavity"
	Poster THPO072 [1.150 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO072
About •	paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPO076	Multiphysics Design Studies of a Superconducting Quarter-wave Resonator at Peking University	cavity, multipactoring, simulation, SRF	863
	M. Chen, S. Chen, A.Q. Cheng, W. Cheng, J.K. Hao, S.W. Quan, F. Zhu PKU, Beijing, People’s Republic of China
	Funding: This work is supported by National Basic Research Program (2014CB845504) A 81.25MHz, geometric β=0.046 quarter-wave resonator has been designed and analysed at Peking University. This paper mainly presents the multi-physics studies of this cavity, include electromagnetic design, mechanical analysis and multipacting simulation, to predict its behaviour under practical operating process. Various transverse vibration modes of inner conductor were found under different fixed conditions and an asymmetric shorting plate was adopted to avoid high possibility of multipacting "quarter-wave resonator" "multiphysics" "multipacting" "frequency detuning" "stiffening design"
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO076
About •	paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPO115	Consolidation and Extension of the High-gradient LINAC RF Technology at PSI	FEL, linac, cavity, polarization	937
	P. Craievich, M. Bopp, H.-H. Braun, A. Citterio, H. Fitze, T. Garvey, T. Kleeb, F. Löhl, F. Marcellini, M. Pedrozzi, J.-Y. Raguin, L. Rivkin, K. Rolli, R. Zennaro PSI, Villigen PSI, Switzerland
	For SwissFEL a novel production process for high-gradient, high-precision C-band accelerating structures had been developed at PSI and was implemented for series production in collaboration with industry. The copper parts of the structures are machined and brazed relying on a ultra-high precision manufacturing process and tight mechanical tolerances; no RF tuning methods are applied during or after production. So far none of the structures of the series production failed during RF power conditioning and operation in the SwissFEL facility. After completing the series production for SwissFEL PSI started collaborations with CERN, ELETTRA and DESY for applying the production process and related know-how to other frequencies, namely S-band (3 GHz) and X-band (12 GHz). This paper gives an overview on the ongoing and planned R\&D activities and results obtained so far.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO115
About •	paper received ※ 11 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUPO049

Nitrogen Doping Study With 1.3 GHz Single Cell Superconducting Cavities

cavity, vacuum, niobium, superconducting-cavity

442

S. Chen, M. Chen, L.W. Feng, J.K. Hao, L. Lin, K.X. Liu, S.W. Quan, F. Wang, F. Zhu
PKU, Beijing, People’s Republic of China

Nitrogen doping studies were carried out at Peking University. A series of 1.3 GHz single cell cavities fabricated with OTIC large grain niobium material were annealed and doped in the furnace of Peking University, and electropolished by a simple EP device. Light doping recipe and heavy doping recipe are both adopted for comparison. The results and analysis are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO049

About •

paper received ※ 12 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019

Export •

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

TUPO065

Improvement of Cavity Performance by Nitrogen Doping at KEK

cavity, ECR, SRF, solenoid

480

T. Okada, Y. Hori, E. Kako, T. Konomi, H. Sakai, K. Umemori, Y. Yamamoto
Sokendai, Ibaraki, Japan
T. Dohmae, Y. Hori, E. Kako, T. Konomi, T. Saeki, T. Saeki, H. Sakai, K. Umemori, Y. Yamamoto
KEK, Ibaraki, Japan
J. Kamiya
JAEA/J-PARC, Tokai-mura, Japan
S. Kurosawa, K. Takeishi
JAEA, Ibaraki-ken, Japan

Nitrogen doping experiments in single-cell and 3-cell niobium cavities were carried out at KEK. After annealing at 800 deg C for 3 hours, pure nitrogen gas with a pressure of 3 Pa for 20 minutes and 3 minutes were introduced for doping in a furnace in J-PARC, respectively. Removing surface in 5 um and 20 um by electropolishing were performed prior to the vertical tests, respectively. Increases of a quality factor at 2K and reduction of the BCS resistance with respect to an accelerating gradient were observed in both cavities.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO065

About •

paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

Export •

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

TUPO076

An Innovative Nb3Sn Film Approach and Its Potential for SRF Applications

cavity, SRF, site, cathode

513

E.Z. Barzi, D. Turrioni, C. Ciaccia
Fermilab, Batavia, Illinois, USA
G.V. Eremeev, R.L. Geng, R.A. Rimmer, A-M. Valente-Feliciano
JLab, Newport News, Virginia, USA
S. Falletta
Politecnico di Torino, Torino, Italy
H. Hayano, T. Saeki
KEK, Ibaraki, Japan
H. Ito
Sokendai, Ibaraki, Japan
A. Kikuchi
NIMS, Tsukuba, Ibaraki, Japan

Funding: Work supported by U.S. DOE contract No. DE-AC02-07CH11359
A novel electro-chemical technique to produce Nb3Sn films on Nb substrates was developed and optimized at Fermilab. The Nb3Sn phase is obtained in a two-electrode cell, by electrodeposition from aqueous solutions of Sn layers and Cu intermediate layers onto Nb substrates. Subsequent thermal treatments in inert atmosphere are realized at a maximum temperature of 700°C to obtain the Nb3Sn superconducting phase. Several superconduct-ing Nb3Sn films were obtained on Nb substrates by study-ing and optimizing most parameters of the electro-plating process. Samples were characterized at Fermilab, NIMS, KEK and JLAB, including EPMA analyses, DC and in-ductive tests of critical temperature Tc0, and lower critical field Hc1(4.2 K) by SQUID. In parallel to sample devel-opment and fabrication at FNAL, at JLAB and KEK effort was put into etching and electro-polishing techniques adequate to remove the Cu and bronze phases from the samples’ outer surface. This is necessary prior to meas-urements at JLAB of the surface impedance of flat sam-ples in a setup that make use of an RF host cavity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO076

About •

paper received ※ 21 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019

Export •

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

TUPO113

Beam Dynamics Studies Through Dielectric THz Accelerating Structures

GUI, simulation, vacuum, linac

569

R. Apsimon, G. Burt, A.L. Healy, S.P. Jamison
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
R.B. Appleby, E.J.H. Smith
UMAN, Manchester, United Kingdom
A. Latina
CERN, Geneva, Switzerland

As conventional RF accelerating schemes approach the physical limit of accelerating gradient, the accelerator community is increasingly looking at novel accelerating techniques to overcome these limitations. Moving from the RF to the THz frequency range, higher acceleration gradients of high energy beams can be achieved in compact structures. Beam dynamics studies are crucial as part of the design of novel accelerating structures to maximise the output beam current as well as the accelerating gradient. In this paper we present beam dynamics simulations through dielectric lined waveguide structures using novel techniques to simulate broadband signals for particle tracking studies in RF-Track. The beam parameters through the structure are optimised and we study the dynamics of general broadband accelerating structures.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO113

About •

paper received ※ 13 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

Export •

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

THPO066

First High Power Test of the ESS High Beta Elliptical Cavity

cavity, SRF, linac, flattop

841

H. Li, L. Hermansson, M. Jobs, R.J.M.Y. Ruber, R. Santiago Kern
Uppsala University, Uppsala, Sweden
G. Devanz, T. Hamelin
CEA/DSM/IRFU, France

ESS, the European Spallation Source, will adopt elliptical multi-cell superconducting cavities with a beta value of 0.86 to accelerate the proton beam up to 2 GeV at the last section of the linac. A 5-cell high-beta cavity for ESS project was tested with high power at FREIA Laboratory. A pulse mode test stand based on a self-excited loop was used in this test. The qualification of the cavity package involved a 5-cell elliptical cavity, a fundamental power coupler, a cold tuning system, LLRF system and a RF station. These tests represented an important verification before the series production. This paper presents the test configuration, RF conditioning history, first high power performance and experience of this cavity package.

Slides THPO066 [1.437 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO066

About •

paper received ※ 14 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

Export •

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

THPO072

Cryogenic Tests of the Superconducting β=0.069 CH-cavities for the HELIAC-project

cavity, linac, heavy-ion, cryogenics

855

M. Basten, M. Busch, H. Podlech, M. Schwarz
IAP, Frankfurt am Main, Germany
K. Aulenbacher, W.A. Barth, F.D. Dziuba, V. Gettmann, T. Kürzeder, M. Miski-Oglu
HIM, Mainz, Germany
W.A. Barth, M. Heilmann, S. Yaramyshev
GSI, Darmstadt, Germany

In the future the existing UNILAC (UNIversal Linear Accelerator) at GSI will be most exclusively used as an injector for FAIR to provide short pulse high intensity heavy ion beams at low repetition rates [Barth3]. A new superconducting (sc) continuous wave (cw) high intensity heavy ion Linac should provide ion beams with max. duty factor above the coulomb barrier for the Super Heavy Element (SHE) program at GSI. The fundamental Linac design comprises a low energy beam transport (LEBT)-section followed by a sc Drift Tube Linac (DTL) consisting of sc Crossbar-H-mode (CH) structures for acceleration up to 7.3 MeV/u [*]. After the successful test and commissioning of the first demonstrator section with heavy ion beam from the HLI in 2017 [**], the next two sc CH-structures have been constructed and the first one has been extensively tested at cryogenic temperatures at the Institute for Applied Physics (IAP) at Goethe University Frankfurt (GUF). The results of the final cold test of the first CH-structure as well as the next steps realizing a new sc cw heavy ion LINAC at GSI will be presented.
[*]W. Barth et al., "Further investigations for a superconducting cw-Linac at GSI"
[**]W. Barth et al., "First high intensity heavy ion beam tests with a superconducting multi gap CH-cavity"

Poster THPO072 [1.150 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO072

About •

paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

Export •

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

THPO076

Multiphysics Design Studies of a Superconducting Quarter-wave Resonator at Peking University

cavity, multipactoring, simulation, SRF

863

M. Chen, S. Chen, A.Q. Cheng, W. Cheng, J.K. Hao, S.W. Quan, F. Zhu
PKU, Beijing, People’s Republic of China

Funding: This work is supported by National Basic Research Program (2014CB845504)
A 81.25MHz, geometric β=0.046 quarter-wave resonator has been designed and analysed at Peking University. This paper mainly presents the multi-physics studies of this cavity, include electromagnetic design, mechanical analysis and multipacting simulation, to predict its behaviour under practical operating process. Various transverse vibration modes of inner conductor were found under different fixed conditions and an asymmetric shorting plate was adopted to avoid high possibility of multipacting
"quarter-wave resonator"
"multiphysics"
"multipacting"
"frequency detuning"
"stiffening design"

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO076

About •

paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

Export •

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

THPO115

Consolidation and Extension of the High-gradient LINAC RF Technology at PSI

FEL, linac, cavity, polarization

937

P. Craievich, M. Bopp, H.-H. Braun, A. Citterio, H. Fitze, T. Garvey, T. Kleeb, F. Löhl, F. Marcellini, M. Pedrozzi, J.-Y. Raguin, L. Rivkin, K. Rolli, R. Zennaro
PSI, Villigen PSI, Switzerland

For SwissFEL a novel production process for high-gradient, high-precision C-band accelerating structures had been developed at PSI and was implemented for series production in collaboration with industry. The copper parts of the structures are machined and brazed relying on a ultra-high precision manufacturing process and tight mechanical tolerances; no RF tuning methods are applied during or after production. So far none of the structures of the series production failed during RF power conditioning and operation in the SwissFEL facility. After completing the series production for SwissFEL PSI started collaborations with CERN, ELETTRA and DESY for applying the production process and related know-how to other frequencies, namely S-band (3 GHz) and X-band (12 GHz). This paper gives an overview on the ongoing and planned R\&D activities and results obtained so far.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO115

About •

paper received ※ 11 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019

Export •

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