LINAC2016 - List of Keywords (feedback)

Paper	Title	Other Keywords	Page
MOP106021	Superconducting Traveling Wave Cavity Tuning Studies	cavity, accelerating-gradient, SRF, acceleration	327
	R.A. Kostin LETI, Saint-Petersburg, Russia P.V. Avrakhov, A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA N. Solyak, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	Funding: Work supported by US DOE SBIR # DE-SC0006300 Superconducting traveling wave cavity (SCTW) can provide 1.2-1.4 times larger accelerating gradient than conventional standing wave SRF cavities [1]. Firstly, traveling wave opens the way to use other than Pi-mode phase advance per cell which increase transit time factor. Secondly, traveling wave is not so sensitive to cavity length as standing wave, which length is limited to 1 meter because of field flatness degradation. 3 cell SCTW cavity was proposed [2] and built for high gradient traveling wave demonstration and tuning studies. This paper describes analytical model that was used for cavity development. Tuning properties and requirements are also discussed. ' r.kostin@euclidtechlabs.com
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOP106021
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TUPLR040	The RF System of Thomx	cavity, HOM, controls, storage-ring	551
	M. El Khaldi, R. Marie, H. Monard, F. Wicek LAL, Orsay, France M. Diop, L.R. Lopes, A. Loulergue, M. Louvet, P. Marchand, F. Ribeiro, R. Sreedharan SOLEIL, Gif-sur-Yvette, France
	The RF system of the ThomX electron storage ring consists in a 500 MHz single cell copper cavity of the ELETTRA type, powered with a 50 kW CW solid state power amplifier (SSPA), and the associated Low Level RF feedback and control loops. The low operating energy of 50/70 MeV makes the impedances of the cavity higher order modes (HOMs) particularly critical for the beam stability. Their parasitic effects on the beam can be cured by HOM frequency shifting techniques, based on a fine temperature tuning and a dedicated plunger. A typical cavity temperature stability of ± 0.05°C within a range from 30 up to 70 °C can be achieved by a precise control of its water cooling temperature. On the other hand, the tuning of the cavity fundamental mode is achieved by changing its axial length by means of a motor-driven mechanism. A general description of the system and the state of its progress are reported together with some considerations of the effects of beam cavity interactions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR040
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TUPLR046	Design, Fabrication, Installation and Operation of New 201 MHz RF Systems at LANSCE	DTL, linac, controls, cavity	564
	J.T.M. Lyles, W.C. Barkley, R.E. Bratton, M.S. Prokop, D. Rees LANL, Los Alamos, New Mexico, USA
	Funding: Work supported by the United States Department of Energy, National Nuclear Security Agency, under contract DE-AC52-06NA25396. The LANSCE RM project has restored the proton linac to high power capability after the RF power tube manufacturer could no longer provide devices that consistently met the high average power requirement. Diacrodes® now supply RF power to three of the four DTL tanks. These tetrodes reuse the existing infrastructure including water-cooling systems, coaxial transmission lines, high voltage power supplies and capacitor banks. Each final power amplifier system uses a combined pair of LANL-designed cavity amplifiers using the TH628L Diacrode® to produce up to 3.5 MW peak and 420 kW of mean power. A new intermediate power amplifier was developed using a TH781 tetrode. These amplifiers are the first production of new high power 200 MHz RF sources at accelerators in three decades. Design and prototype testing of the high power stages was completed in 2012, with commercialization following in 2013. Each installation was accomplished during a 4 to 5 month beam outage each year staring in 2014. Simultaneously, a new digital low-level RF control system was designed and tested, and placed into operation this year, meeting the stringent field control requirements for the linac. The rapid-paced installation project changed over from old to new RF systems while minimizing beam downtime to the user facility schedule.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR046
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THPRC009	IF-Mixture Performance During Cavity Conditioning at STF-KEK	cavity, controls, LLRF, flattop	785
	S.B. Wibowo Sokendai, Ibaraki, Japan T. Matsumoto, S. Michizono, T. Miura, F. Qiu KEK, Ibaraki, Japan
	The Superconducting rf Test Facility (STF) at High Energy Accelerator Research Organization (KEK) was built for research and development of the International Linear Collider (ILC). In order to satisfy the stability requirement of the accelerating field, a digital low-level RF (LLRF) control system is employed. In this control system, signal from a cavity is down-converted into intermediate frequency (IF) signal before being digitized by analog-to-digital converter (ADC). In order to reduce the required number of ADCs, we proposed a technique that combines several IFs and to be read by a single ADC. Signal reconstruction of each IF is performed by digital signal processing. The performance of this technique, which is named IF-mixture, is reported in this paper.
	Poster THPRC009 [0.992 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPRC009
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THPLR008	3-Cell Superconducting Traveling Wave Cavity Tuning at Room Temperature	cavity, accelerating-gradient, SRF, factory	858
	R.A. Kostin LETI, Saint-Petersburg, Russia P.V. Avrakhov, A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA T.N. Khabiboulline, A.M. Rowe, N. Solyak, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	Funding: Work supported by US DOE SBIR # DE-SC0006300 A superconducting traveling wave (SCTW) cavity with a feedback waveguide will support a higher average acceleration gradient compared to conventional SRF standing wave cavities [1]. Euclid Techlabs, in collaboration with Fermilab, previously demonstrated a high accelerating gradient in a single cell cavity with a feedback waveguide [2], and the new waveguide design did not limit the cavity performance. The next step is high gradient traveling wave SRF cavity test. A 3-Cell SCTW cavity was designed and developed [3] to demonstrate the SRF traveling wave regime. Two Nb SCTW cavities were built, characterized and cold tested in 2016. This paper presents the results of cavity inspection, field flatness analysis, along with a discussion of the tuning procedure.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPLR008
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THPLR047	The Beam Energy Feedback System in Beijing Electron Positron Collider II Linear Accelerator	injection, electron, positron, controls	962
	S.Z. Wang, Y.L. Chi, X. Huang IHEP, Beijing, People's Republic of China
	The beam energy feedback system in Beijing electron positron collider II (BEPCII) linear accelerator consists of three parts. They are the beam energy measurement In-put/Output Controller (BEM IOC), the Graphical User Interface (GUI) based on Qt platform and the phasing system. This article describes the implementation of this system and the online testing which has been passed on March 16th, 2016. By using this feedback system, the injection rate and the energy fluctuation of the injection beam has been improved a lot. Now this system is steady running in the control room of BEPCII linear accelerator.
	Poster THPLR047 [0.569 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPLR047
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Paper

Title

Other Keywords

Page

MOP106021

Superconducting Traveling Wave Cavity Tuning Studies

cavity, accelerating-gradient, SRF, acceleration

327

R.A. Kostin
LETI, Saint-Petersburg, Russia
P.V. Avrakhov, A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA
N. Solyak, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

Funding: Work supported by US DOE SBIR # DE-SC0006300
Superconducting traveling wave cavity (SCTW) can provide 1.2-1.4 times larger accelerating gradient than conventional standing wave SRF cavities [1]. Firstly, traveling wave opens the way to use other than Pi-mode phase advance per cell which increase transit time factor. Secondly, traveling wave is not so sensitive to cavity length as standing wave, which length is limited to 1 meter because of field flatness degradation. 3 cell SCTW cavity was proposed [2] and built for high gradient traveling wave demonstration and tuning studies. This paper describes analytical model that was used for cavity development. Tuning properties and requirements are also discussed.
' r.kostin@euclidtechlabs.com

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOP106021

Export •

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

TUPLR040

The RF System of Thomx

cavity, HOM, controls, storage-ring

551

M. El Khaldi, R. Marie, H. Monard, F. Wicek
LAL, Orsay, France
M. Diop, L.R. Lopes, A. Loulergue, M. Louvet, P. Marchand, F. Ribeiro, R. Sreedharan
SOLEIL, Gif-sur-Yvette, France

The RF system of the ThomX electron storage ring consists in a 500 MHz single cell copper cavity of the ELETTRA type, powered with a 50 kW CW solid state power amplifier (SSPA), and the associated Low Level RF feedback and control loops. The low operating energy of 50/70 MeV makes the impedances of the cavity higher order modes (HOMs) particularly critical for the beam stability. Their parasitic effects on the beam can be cured by HOM frequency shifting techniques, based on a fine temperature tuning and a dedicated plunger. A typical cavity temperature stability of ± 0.05°C within a range from 30 up to 70 °C can be achieved by a precise control of its water cooling temperature. On the other hand, the tuning of the cavity fundamental mode is achieved by changing its axial length by means of a motor-driven mechanism. A general description of the system and the state of its progress are reported together with some considerations of the effects of beam cavity interactions.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR040

Export •

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

TUPLR046

Design, Fabrication, Installation and Operation of New 201 MHz RF Systems at LANSCE

DTL, linac, controls, cavity

564

J.T.M. Lyles, W.C. Barkley, R.E. Bratton, M.S. Prokop, D. Rees
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by the United States Department of Energy, National Nuclear Security Agency, under contract DE-AC52-06NA25396.
The LANSCE RM project has restored the proton linac to high power capability after the RF power tube manufacturer could no longer provide devices that consistently met the high average power requirement. Diacrodes® now supply RF power to three of the four DTL tanks. These tetrodes reuse the existing infrastructure including water-cooling systems, coaxial transmission lines, high voltage power supplies and capacitor banks. Each final power amplifier system uses a combined pair of LANL-designed cavity amplifiers using the TH628L Diacrode® to produce up to 3.5 MW peak and 420 kW of mean power. A new intermediate power amplifier was developed using a TH781 tetrode. These amplifiers are the first production of new high power 200 MHz RF sources at accelerators in three decades. Design and prototype testing of the high power stages was completed in 2012, with commercialization following in 2013. Each installation was accomplished during a 4 to 5 month beam outage each year staring in 2014. Simultaneously, a new digital low-level RF control system was designed and tested, and placed into operation this year, meeting the stringent field control requirements for the linac. The rapid-paced installation project changed over from old to new RF systems while minimizing beam downtime to the user facility schedule.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR046

Export •

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

THPRC009

IF-Mixture Performance During Cavity Conditioning at STF-KEK

cavity, controls, LLRF, flattop

785

S.B. Wibowo
Sokendai, Ibaraki, Japan
T. Matsumoto, S. Michizono, T. Miura, F. Qiu
KEK, Ibaraki, Japan

The Superconducting rf Test Facility (STF) at High Energy Accelerator Research Organization (KEK) was built for research and development of the International Linear Collider (ILC). In order to satisfy the stability requirement of the accelerating field, a digital low-level RF (LLRF) control system is employed. In this control system, signal from a cavity is down-converted into intermediate frequency (IF) signal before being digitized by analog-to-digital converter (ADC). In order to reduce the required number of ADCs, we proposed a technique that combines several IFs and to be read by a single ADC. Signal reconstruction of each IF is performed by digital signal processing. The performance of this technique, which is named IF-mixture, is reported in this paper.

Poster THPRC009 [0.992 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPRC009

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

THPLR008

3-Cell Superconducting Traveling Wave Cavity Tuning at Room Temperature

cavity, accelerating-gradient, SRF, factory

858

R.A. Kostin
LETI, Saint-Petersburg, Russia
P.V. Avrakhov, A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA
T.N. Khabiboulline, A.M. Rowe, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

Funding: Work supported by US DOE SBIR # DE-SC0006300
A superconducting traveling wave (SCTW) cavity with a feedback waveguide will support a higher average acceleration gradient compared to conventional SRF standing wave cavities [1]. Euclid Techlabs, in collaboration with Fermilab, previously demonstrated a high accelerating gradient in a single cell cavity with a feedback waveguide [2], and the new waveguide design did not limit the cavity performance. The next step is high gradient traveling wave SRF cavity test. A 3-Cell SCTW cavity was designed and developed [3] to demonstrate the SRF traveling wave regime. Two Nb SCTW cavities were built, characterized and cold tested in 2016. This paper presents the results of cavity inspection, field flatness analysis, along with a discussion of the tuning procedure.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPLR008

Export •

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

THPLR047

The Beam Energy Feedback System in Beijing Electron Positron Collider II Linear Accelerator

injection, electron, positron, controls

962

S.Z. Wang, Y.L. Chi, X. Huang
IHEP, Beijing, People's Republic of China

The beam energy feedback system in Beijing electron positron collider II (BEPCII) linear accelerator consists of three parts. They are the beam energy measurement In-put/Output Controller (BEM IOC), the Graphical User Interface (GUI) based on Qt platform and the phasing system. This article describes the implementation of this system and the online testing which has been passed on March 16th, 2016. By using this feedback system, the injection rate and the energy fluctuation of the injection beam has been improved a lot. Now this system is steady running in the control room of BEPCII linear accelerator.

Poster THPLR047 [0.569 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPLR047

Export •

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