LINAC2018 - Classification: Electron Accelerators and Applications / Colliders

Paper	Title	Page
THPO001	Design Study on CEPC Positron Damping Ring System	672
	D. Wang, Y.L. Chi, J. Gao, D.J. Gong, C. Meng, G. Pei, J.R. Zhang IHEP, Beijing, People’s Republic of China
	The primary purpose of CEPC damping ring is to reduce the transverse phase spaces of positron beam to suitably small value at the beginning of linac and hence reduce the beam loss in the booster. Before damping ring, an energy spread compression structure is designed to match the RF acceptance of damping ring. A longitudinal bunch length control is also necessary to meet the energy spread requirement in the linac by a bunch compressor system after the damping ring. Both designs for damping ring and energy/bunch compressors are discussed in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO001
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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THPO002	Investigation of SRF Elliptical Cavities Made by New Nb Materials in KEK	676
	T. Dohmae, K. Umemori, Y. Watanabe, M. Yamanaka KEK, Ibaraki, Japan T. Okada Sokendai, Ibaraki, Japan
	Cost reduction for cavity fabrication is currently main issue to realize international linear collider. Cavity fabrication facility (CFF) in KEK is approaching this issue from a point of view of materials for cavities. CFF had fabricated SRF elliptical cavities made by two types of niobium; one is high tantalum contained and low RRR (< 100) fine grain niobium, and the other is high tantalum contained and RRR < 300 large grain (LG) niobium. Former was melted two times (normally five times) which results RRR recovery up to around 300, and used for cell parts. Two 3-cell cavities were fabricated for each material respectively and vertical tested. One of these cavity made by LG achieved accelerator gradients of more than 40 MV/m. In this report, cavity materials and vertical test results are presented in detail.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO002
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)

THPO003	L-band Resonant Ring for Testing RF Windows for ILC	679
SPWR005	use link to see paper's listing under its alternate paper code
	B. Du, N. Liu Sokendai - Hayama, Hayama, Japan T. Matsumoto, S. Michizono, T. Miura, F. Qiu KEK, Ibaraki, Japan T. Matsumoto, T. Miura, F. Qiu Sokendai, Ibaraki, Japan
	A resonant ring is widely used for the breakdown test of RF components under high power. It can reach power gain of more than 10dB, which is limited by the attenua-tion of the ring. An L-band resonant ring is constructed for testing RF components of International Linear Collid-er (ILC) which is based on an RF frequency of 1.3GHz. The target of the high power test is 5 MW. We have fin-ished the test of an input power of 500 W using a solid state amplifier, and the principle of the resonant ring is verified. The resonant ring is tuned to an optimal condi-tion, which is preparation for high power operation. This paper details the principle, construction, and test of the L-band resonant ring.
	Poster THPO003 [2.301 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO003
About •	paper received ※ 13 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
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THPO004	Pulsed Operation of CEBAF for JLEIC Injection	682
	J. Guo, J.M. Grames, R. Kazimi, F. Lin, T. E. Plawski, R.A. Rimmer, H. Wang JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. JLab Electron Ion Collider (JLEIC) is planning to use the recently upgraded 12 GeV CEBAF 1497 MHz SRF CW recirculating linac as a full-energy injector for the electron collider ring. The JLEIC electron injection requires 3-4µs long bunch trains with a 20-400ms spacing in between, resulting in uneven beam loading for the CW CEBAF. With the high beam current in JLEIC collider rings, the low duty factor of injection also requires to a very high pulsed beam current from CEBAF, exacerbating the transient beam loading issue. In this paper, we will present CEBAFs detailed pulsed operation scheme for JLEIC injection, as well as some experimental results at CEBAF.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO004
About •	paper received ※ 20 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)

THPO005	High Aspect Ratio Beam Generation with the Phase-space Rotation Technique for Linear Colliders	685
	M. Kuriki HU/AdSM, Higashi-Hiroshima, Japan H. Hayano, X.J. Jin, T. Konomi, Y. Seimiya, N. Yamamoto KEK, Ibaraki, Japan S. Kashiwagi Tohoku University, Research Center for Electron Photon Science, Sendai, Japan P. Piot Northern Illinois University, DeKalb, Illinois, USA J.G. Power ANL, Argonne, Illinois, USA K. Sakaue Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan M. Washio RISE, Tokyo, Japan H.W. Zhao IMP/CAS, Lanzhou, People’s Republic of China
	Funding: This work is partly supported by Grant-in-Aid for Scientific Research (B) and US-Japan Science and Technology Cooperation Program in High Energy Physics. Linear colliders is the only way to realize e⁺ e⁻ collision at higher energy beyond the limit of ring colliders by the huge synchrotron radiation energy loss. In the linear collider, the beam current should be much smaller comparing to the ring collider to save the required electricity. A way to realize an enough luminosity with the small beam current and less energy spread by Beamstrahlung, is collision in flat beam. This high aspect ratio beam can be made by phase-space rotation technique instead of the conventional way with DR (Damping Ring). We present a simulation of this technique and pilot experiments at KEK-STF and ANL WFA.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO005
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)

Paper

Title

Page

Design Study on CEPC Positron Damping Ring System

672

D. Wang, Y.L. Chi, J. Gao, D.J. Gong, C. Meng, G. Pei, J.R. Zhang
IHEP, Beijing, People’s Republic of China

The primary purpose of CEPC damping ring is to reduce the transverse phase spaces of positron beam to suitably small value at the beginning of linac and hence reduce the beam loss in the booster. Before damping ring, an energy spread compression structure is designed to match the RF acceptance of damping ring. A longitudinal bunch length control is also necessary to meet the energy spread requirement in the linac by a bunch compressor system after the damping ring. Both designs for damping ring and energy/bunch compressors are discussed in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO001

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)

THPO002

Investigation of SRF Elliptical Cavities Made by New Nb Materials in KEK

676

T. Dohmae, K. Umemori, Y. Watanabe, M. Yamanaka
KEK, Ibaraki, Japan
T. Okada
Sokendai, Ibaraki, Japan

Cost reduction for cavity fabrication is currently main issue to realize international linear collider. Cavity fabrication facility (CFF) in KEK is approaching this issue from a point of view of materials for cavities. CFF had fabricated SRF elliptical cavities made by two types of niobium; one is high tantalum contained and low RRR (< 100) fine grain niobium, and the other is high tantalum contained and RRR < 300 large grain (LG) niobium. Former was melted two times (normally five times) which results RRR recovery up to around 300, and used for cell parts. Two 3-cell cavities were fabricated for each material respectively and vertical tested. One of these cavity made by LG achieved accelerator gradients of more than 40 MV/m. In this report, cavity materials and vertical test results are presented in detail.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO002

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)

THPO003

L-band Resonant Ring for Testing RF Windows for ILC

679

SPWR005

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

B. Du, N. Liu
Sokendai - Hayama, Hayama, Japan
T. Matsumoto, S. Michizono, T. Miura, F. Qiu
KEK, Ibaraki, Japan
T. Matsumoto, T. Miura, F. Qiu
Sokendai, Ibaraki, Japan

A resonant ring is widely used for the breakdown test of RF components under high power. It can reach power gain of more than 10dB, which is limited by the attenua-tion of the ring. An L-band resonant ring is constructed for testing RF components of International Linear Collid-er (ILC) which is based on an RF frequency of 1.3GHz. The target of the high power test is 5 MW. We have fin-ished the test of an input power of 500 W using a solid state amplifier, and the principle of the resonant ring is verified. The resonant ring is tuned to an optimal condi-tion, which is preparation for high power operation. This paper details the principle, construction, and test of the L-band resonant ring.

Poster THPO003 [2.301 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO003

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)

THPO004

Pulsed Operation of CEBAF for JLEIC Injection

682

J. Guo, J.M. Grames, R. Kazimi, F. Lin, T. E. Plawski, R.A. Rimmer, H. Wang
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
JLab Electron Ion Collider (JLEIC) is planning to use the recently upgraded 12 GeV CEBAF 1497 MHz SRF CW recirculating linac as a full-energy injector for the electron collider ring. The JLEIC electron injection requires 3-4µs long bunch trains with a 20-400ms spacing in between, resulting in uneven beam loading for the CW CEBAF. With the high beam current in JLEIC collider rings, the low duty factor of injection also requires to a very high pulsed beam current from CEBAF, exacerbating the transient beam loading issue. In this paper, we will present CEBAFs detailed pulsed operation scheme for JLEIC injection, as well as some experimental results at CEBAF.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO004

About •

paper received ※ 20 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)

THPO005

High Aspect Ratio Beam Generation with the Phase-space Rotation Technique for Linear Colliders

685

M. Kuriki
HU/AdSM, Higashi-Hiroshima, Japan
H. Hayano, X.J. Jin, T. Konomi, Y. Seimiya, N. Yamamoto
KEK, Ibaraki, Japan
S. Kashiwagi
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
P. Piot
Northern Illinois University, DeKalb, Illinois, USA
J.G. Power
ANL, Argonne, Illinois, USA
K. Sakaue
Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan
M. Washio
RISE, Tokyo, Japan
H.W. Zhao
IMP/CAS, Lanzhou, People’s Republic of China

Funding: This work is partly supported by Grant-in-Aid for Scientific Research (B) and US-Japan Science and Technology Cooperation Program in High Energy Physics.
Linear colliders is the only way to realize e⁺ e⁻ collision at higher energy beyond the limit of ring colliders by the huge synchrotron radiation energy loss. In the linear collider, the beam current should be much smaller comparing to the ring collider to save the required electricity. A way to realize an enough luminosity with the small beam current and less energy spread by Beamstrahlung, is collision in flat beam. This high aspect ratio beam can be made by phase-space rotation technique instead of the conventional way with DR (Damping Ring). We present a simulation of this technique and pilot experiments at KEK-STF and ANL WFA.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO005

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)