LINAC2018 - Classification: Technology / Room temperature RF

Paper	Title	Page
MO2A03	Technology Developments for ELI-NP Gamma Beam System	13
	L. Piersanti, D. Alesini, A. Battisti, M. Bellaveglia, S. Bini, F. Cardelli, R.D. Di Raddo, A. Falone, A. Gallo, V.L. Lollo, L. Pellegrino, S. Pioli, S. Tomassini, A. Variola INFN/LNF, Frascati (Roma), Italy N. Beaugerard SEIV, Mérignac, France K. Cassou, D. Douillet, K. Dupraz, T. Le Barillec, A. Martens, C.F. Ndiaye, Y. Peinaud, Z.F. Zomer LAL, Orsay, France L. Ficcadenti, A. Mostacci, L. Palumbo, V. Pettinacci INFN-Roma, Roma, Italy M. Migliorati INFN-Roma1, Rome, Italy D.T. Palmer, L. Serafini Istituto Nazionale di Fisica Nucleare, Milano, Italy H. Rocipon ALSYOM, Argebteuil, France
	ELI-NP gamma beam system (GBS) is a linac based gamma-source in construction in Magurele (RO) by the European consortium EuroGammaS led by INFN. Photons with tunable energy, from 0.2 to 19.5 MeV, and with intensity and brilliance beyond the state of the art, will be produced by Compton back-scattering between a high quality electron beam (up to 740 MeV) and an intense laser pulse at 100 Hz repetition rate. Production of very intense photon flux with narrow bandwidth requires multi-bunch operation and laser recirculation at the interaction point. In this paper, the main technological developments carried out by the EuroGammaS consortium for the generation of the ELI-NP gamma beam will be described with a special emphasis on the electron linac technology, such as: RF-gun and C-band accelerating structures design fabrication and tests; low level RF (LLRF) and synchronization systems specifications and development. Finally, the laser recirculation apparatus design is briefly described and first results reported.
	Slides MO2A03 [9.121 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MO2A03
About •	paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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TU1A02	Development of Normal-conducting High-gradient Accelerating Structures
	J. Shi TUB, Beijing, People’s Republic of China
	X-band high-gradient accelerating structures operating at the gradient of 80-100MV/m are proposed for different applications including compact linear collider and compact X-ray facilities. A traveling-wave structure as well as single-cell test structures with choke-mode damping feature were developed in Tsinghua University and high-power tested. A prototype structure with CLIC-based design, namely T24-THU#1, has reached 110 MV/m and several choke-mode single-cell structures reached 130MV/m during test. The high-gradient technique will be applied to Tsinghua Thomson-scattering X-ray source with two new developed 0.6m-long structures for 80MV/m acceleration.
	Slides TU1A02 [10.927 MB]
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THPO108	Development of an High Gradient Side Coupled Cavity for PROBE	924
THOP08	use link to see paper's listing under its alternate paper code
	S. Pitman, R. Apsimon, G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom N. Catalán Lasheras, A. Grudiev, W. Wuensch CERN, Geneva, Switzerland H.L. Owen UMAN, Manchester, United Kingdom
	The PROBE project aims to develop a high gradient proton accelerator for protons with energy around 250-350 MeV for proton radiography. Detailed studies have shown that the optimum design is a side coupled cavity at S-band. With an aperture of 8 mm a gradient of 54 MV/m can be obtained with 13 MW of RF power in a 30 cm structure. A prototype cavity has been machined by VDL and diffusion bonded by Bodycote. We present initial measurements of the prototype.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO108
About •	paper received ※ 17 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)

THPO109	A New Spherical Pulse Compressor Working with Degenerated "Whispering Gallery" Mode	928
SPWR023	use link to see paper's listing under its alternate paper code
THOP09	use link to see paper's listing under its alternate paper code
	Z.B. Li, W. Fang, Q. Gu, Z.T. Zhao SINAP, Shanghai, People’s Republic of China A. Grudiev CERN, Geneva, Switzerland
	CLIC is focusing on the Compact Linear Collider. To obtain a relatively high accelerating gradient, CLIC utilizes Pulse Compressors to increase the input power of accelerators. This work is to make an alternative design for CLIC pulse compression scheme. There are several kinds of pulse compressor: SLED, BOC, SLED-Ⅱ, spherical pulse compressor and so on. Usually, a spherical cavity, including BOC, can offer a higher Q factor compared with a cylindrical cavity. This design utilizes a spherical cavity working with degenerated Whispering Gallery mode.
	Slides THPO109 [1.738 MB]
	Poster THPO109 [1.913 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO109
About •	paper received ※ 11 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)

THPO111	The Test of RF Breakdowns of CPHS RFQ	931
	W.B. Ye, C. Cheng, X. Guan, J. Shi, X.W. Wang, Q.Z. Xing, S.X. Zheng TUB, Beijing, People’s Republic of China M.C. Wang NINT, Shannxi, People’s Republic of China
	The high accelerating gradient is significant for a compact linear accelerator, and RF breakdowns is a limitation for the high gradient. This work aims to research RF breakdowns of a 325MHz proton Radio Frequency Quadrupole (RFQ) accelerator of the Compact Pulsed Hadron Source（CPHS）. The breakdown rate (BDR) of the RFQ has been measured. Breakdown waveforms have been recorded, which have been used for counting breakdown time distribution and analyzing the location of RF breakdowns.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO111
About •	paper received ※ 12 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)

THPO113	Design of 4 Ampere S-Band Linac Using Slotted Iris Structure for Hom Damping	934
	J. Pang, S. Chen, X. He CAEP/IFP, Mainyang, Sichuan, People’s Republic of China S. Pei, H. Shi, J.R. Zhang IHEP, Beijing, People’s Republic of China
	An S-band LINAC with the operating frequency of 2856 MHz and beam current of 4 A was designed for flash X-ray radiography for hydrodynamic test. The optimization of the parameters of the LINAC was processed to obtain the minimum beam radius and the maximum energy efficiency. For the purpose of reducing the beam orbits offset at the exit of LINAC, a slotted iris accelerating structure would be employed to suppress the transverse Higher Order Modes (HOMs) by cutting four radial slots in the iris to couple the HOMs to SiC loads. In this paper, we present the design of the LINAC and the results of beam dynamic analysis.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO113
About •	paper received ※ 10 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	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

Page

Technology Developments for ELI-NP Gamma Beam System

13

L. Piersanti, D. Alesini, A. Battisti, M. Bellaveglia, S. Bini, F. Cardelli, R.D. Di Raddo, A. Falone, A. Gallo, V.L. Lollo, L. Pellegrino, S. Pioli, S. Tomassini, A. Variola
INFN/LNF, Frascati (Roma), Italy
N. Beaugerard
SEIV, Mérignac, France
K. Cassou, D. Douillet, K. Dupraz, T. Le Barillec, A. Martens, C.F. Ndiaye, Y. Peinaud, Z.F. Zomer
LAL, Orsay, France
L. Ficcadenti, A. Mostacci, L. Palumbo, V. Pettinacci
INFN-Roma, Roma, Italy
M. Migliorati
INFN-Roma1, Rome, Italy
D.T. Palmer, L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano, Italy
H. Rocipon
ALSYOM, Argebteuil, France

ELI-NP gamma beam system (GBS) is a linac based gamma-source in construction in Magurele (RO) by the European consortium EuroGammaS led by INFN. Photons with tunable energy, from 0.2 to 19.5 MeV, and with intensity and brilliance beyond the state of the art, will be produced by Compton back-scattering between a high quality electron beam (up to 740 MeV) and an intense laser pulse at 100 Hz repetition rate. Production of very intense photon flux with narrow bandwidth requires multi-bunch operation and laser recirculation at the interaction point. In this paper, the main technological developments carried out by the EuroGammaS consortium for the generation of the ELI-NP gamma beam will be described with a special emphasis on the electron linac technology, such as: RF-gun and C-band accelerating structures design fabrication and tests; low level RF (LLRF) and synchronization systems specifications and development. Finally, the laser recirculation apparatus design is briefly described and first results reported.

Slides MO2A03 [9.121 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MO2A03

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)

TU1A02

Development of Normal-conducting High-gradient Accelerating Structures

J. Shi
TUB, Beijing, People’s Republic of China

X-band high-gradient accelerating structures operating at the gradient of 80-100MV/m are proposed for different applications including compact linear collider and compact X-ray facilities. A traveling-wave structure as well as single-cell test structures with choke-mode damping feature were developed in Tsinghua University and high-power tested. A prototype structure with CLIC-based design, namely T24-THU#1, has reached 110 MV/m and several choke-mode single-cell structures reached 130MV/m during test. The high-gradient technique will be applied to Tsinghua Thomson-scattering X-ray source with two new developed 0.6m-long structures for 80MV/m acceleration.

Slides TU1A02 [10.927 MB]

Export •

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

THPO108

Development of an High Gradient Side Coupled Cavity for PROBE

924

THOP08

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

S. Pitman, R. Apsimon, G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
N. Catalán Lasheras, A. Grudiev, W. Wuensch
CERN, Geneva, Switzerland
H.L. Owen
UMAN, Manchester, United Kingdom

The PROBE project aims to develop a high gradient proton accelerator for protons with energy around 250-350 MeV for proton radiography. Detailed studies have shown that the optimum design is a side coupled cavity at S-band. With an aperture of 8 mm a gradient of 54 MV/m can be obtained with 13 MW of RF power in a 30 cm structure. A prototype cavity has been machined by VDL and diffusion bonded by Bodycote. We present initial measurements of the prototype.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO108

About •

paper received ※ 17 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)

THPO109

A New Spherical Pulse Compressor Working with Degenerated "Whispering Gallery" Mode

928

SPWR023

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

THOP09

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

Z.B. Li, W. Fang, Q. Gu, Z.T. Zhao
SINAP, Shanghai, People’s Republic of China
A. Grudiev
CERN, Geneva, Switzerland

CLIC is focusing on the Compact Linear Collider. To obtain a relatively high accelerating gradient, CLIC utilizes Pulse Compressors to increase the input power of accelerators. This work is to make an alternative design for CLIC pulse compression scheme. There are several kinds of pulse compressor: SLED, BOC, SLED-Ⅱ, spherical pulse compressor and so on. Usually, a spherical cavity, including BOC, can offer a higher Q factor compared with a cylindrical cavity. This design utilizes a spherical cavity working with degenerated Whispering Gallery mode.

Slides THPO109 [1.738 MB]

Poster THPO109 [1.913 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO109

About •

paper received ※ 11 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)

THPO111

The Test of RF Breakdowns of CPHS RFQ

931

W.B. Ye, C. Cheng, X. Guan, J. Shi, X.W. Wang, Q.Z. Xing, S.X. Zheng
TUB, Beijing, People’s Republic of China
M.C. Wang
NINT, Shannxi, People’s Republic of China

The high accelerating gradient is significant for a compact linear accelerator, and RF breakdowns is a limitation for the high gradient. This work aims to research RF breakdowns of a 325MHz proton Radio Frequency Quadrupole (RFQ) accelerator of the Compact Pulsed Hadron Source（CPHS）. The breakdown rate (BDR) of the RFQ has been measured. Breakdown waveforms have been recorded, which have been used for counting breakdown time distribution and analyzing the location of RF breakdowns.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO111

About •

paper received ※ 12 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)

THPO113

Design of 4 Ampere S-Band Linac Using Slotted Iris Structure for Hom Damping

934

J. Pang, S. Chen, X. He
CAEP/IFP, Mainyang, Sichuan, People’s Republic of China
S. Pei, H. Shi, J.R. Zhang
IHEP, Beijing, People’s Republic of China

An S-band LINAC with the operating frequency of 2856 MHz and beam current of 4 A was designed for flash X-ray radiography for hydrodynamic test. The optimization of the parameters of the LINAC was processed to obtain the minimum beam radius and the maximum energy efficiency. For the purpose of reducing the beam orbits offset at the exit of LINAC, a slotted iris accelerating structure would be employed to suppress the transverse Higher Order Modes (HOMs) by cutting four radial slots in the iris to couple the HOMs to SiC loads. In this paper, we present the design of the LINAC and the results of beam dynamic analysis.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO113

About •

paper received ※ 10 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

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)