IPAC2016 - List of Authors (Geng, H.)

Paper	Title	Page
MOPOY027	Emittance Measurement with Wire Scanners at C-ADS Injector-I	910
	H. Geng, C. Meng, Y.F. Sui, F. Yan, L. Yu, Y.L. Zhao IHEP, Beijing, People's Republic of China
	The transverse emittance at C-ADS injector-I has been measured by the wire scanners at the Medium Energy Beam Transport-I (MEBT1). We have studied the effect of different fitting methods for obtaining the beam sizes on the emittance result, the result will be presented in this paper. The validation study of the quad-scan method with the presence of space charge effect at 10 mA will also be shown, and finally the quad-scan results will be compared with the multi-wire results.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY027
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MOPOY030	Superconducting Cavity Phase and Amplitude Measurement in Low Energy Accelerating Section	919
	C. Meng, H. Geng, F. Yan, Y.L. Zhao IHEP, Beijing, People's Republic of China
	Superconducting linear accelerator is the tendency in linac design with the development of superconducting RF technology. Superconducting cavities used as accelerating section in low energy Hadron linac are more and more common. The 5MeV test stand of CADS accelerator Injector I is composed of an ion source, a LEBT, a 325MHz RFQ, a MEBT, a cryogenic module (CM1) of seven SC spoke cavities (β=0.12) , seven SC solenoids, seven cold BPMs and a beam dump. The phase and amplitude setting of superconducting cavity are very important at the operation of accelerator, so beam based measurement of cavity phase and amplitude is necessary. Beam based phase scan is the most simple and effective method. Because the significant velocity changes in superconducting cavity at low energy section, the effective voltage is changing with cavity phase, meanwhile the synchronous phase is non-linear with LLRF phase. Above two problem make the cavity phase determination difficult. New date fitting method is proposed to solve these problem in this paper. Some measurements of spoke cavities in the CADS CM1 are also presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY030
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MOPOY031	Emittance Measurement with Double-Slit Method in CADS Injector-I	922
	C. Meng, H. Geng, Z. Xue, F. Yan, L. Yu, Y.L. Zhao IHEP, Beijing, People's Republic of China
	The C-ADS accelerator is a CW (Continuous-Wave) proton linac with 1.5 GeV in beam energy, 10 mA in beam current, and 15 MW in beam power. CADS Injector-I accelerator is a 10-mA 10-MeV CW proton linac, which uses a 3.2-MeV normal conducting 4-Vane RFQ and superconducting single-spoke cavities for accelerating. The 5MeV test stand of CADS accelerator Injector I is composed of an ion source, a LEBT, a 325MHz RFQ, a MEBT, a cryogenic module (CM1) of seven SC spoke cavities (β=0.12) , seven SC solenoids, seven cold BPMs and a beam dump. Emittance measurement is very important for the understanding of beam behavior and matching to the next accelerating section. Detailed emittance measurement with double-slit method after CM1 are presented in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY031
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MOPOY032	Beam Twiss Measurement With Ws Including Space Charge Effect	925
	Y.L. Zhao, H. Geng, C. Meng, F. Yan IHEP, Beijing, People's Republic of China
	Wire Scanners (WS) are used to measure beam profile and calculate the transverse Twiss parameters at the entrance of MEBT1 in the CADS injector I test stand. As to data process, the traditional method with transfer map doesn't consider the space charge effect. But, as we know, space charge effect can't be neglected for high intensity accelerators. In this paper, optimization algorithm is used in beam emittance measurement.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY032
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WEOBA02	Commissioning of the China-ADS Injector-I Testing Facility	2048
	F. Yan, J.S. Cao, Y.L. Chi, R. Ge, H. Geng, S. Gu, D.Z. Guo, T.M. Huang, X. Jing, H. Li, R.L. Liu, F. Long, C. Meng, H.F. Ouyang, W.M. Pan, Q.L. Peng, Y.F. Sui, J.L. Wang, S.C. Wang, Z. Xue, Q. Ye, Y.L. Zhao IHEP, Beijing, People's Republic of China
	The 10 MeV accelerator-driven subcritical system (ADS) Injector I test stand at Institute of High Energy Physics (IHEP) is a testing facility dedicated to demonstrate one of the two injector design schemes [Injector Scheme-I, which works at 325 MHz], for the ADS project in China. The ion source was installed since April of 2014, periods of commissioning are regularly scheduled between installation phases of the rest of the injector. 6.05 MeV proton energy has been achieved with average beam current of 10 mA by 7 SC spoke cavities at present. This contribution reports the details of the commissioning results together with the challenges of the CW machine commissioning.
	Slides WEOBA02 [5.243 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOBA02
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THPOR009	Cepc Partial Double Ring Lattice Design	3785
	F. Su Institute of High Energy Physics (IHEP), People's Republic of China S. Bai, T.J. Bian, Z. Duan, J. Gao, H. Geng, D. Wang, Y. Wang, M. Xiao, G. Xu, Y. Zhang IHEP, Beijing, People's Republic of China
	In this paper, we introduced the layout and lattice design of Circular-Electron-Positron-Collider (CEPC) partial double ring (PDR) scheme. The baseline design of CEPC is a single beam-pipe electron positron collider, which has to adopt pretzel orbit scheme. And it is not suitable to serve as a high luminosity Z factory. If we choose partial double ring scheme, we can get a higher luminosity with lower power and be suitable to serve as a high luminosity Z factory. In this paper, we discussed the details of CEPC partial double ring lattice design and showed the dynamic aperture study and optimization.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR009
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THPOR010	CEPC Parameter Choice and Partial Double Ring Design	3788
	D. Wang, S. Bai, T.J. Bian, X. Cui, Z. Duan, J. Gao, H. Geng, Y.Y. Guo, Q. Qin, N. Wang, Y. Wang, M. Xiao, J.Y. Zhai, C. Zhang, Y. Zhang IHEP, Beijing, People's Republic of China W. Chou Fermilab, Batavia, Illinois, USA F. Su Institute of High Energy Physics (IHEP), People's Republic of China
	Funding: Work supported by the National Foundation of Natural Sciences (11505198 and 11575218) In order to avoid the pretzel orbit, CEPC is proposed to use partial double ring scheme in CDR. Based on crab waist scheme, we hope to either increase the luminosity with same beam power as Pre-CDR, or reduce the beam power while keeping the same luminosity in Pre-CDR. FFS with crab sextupoles has been developed and the arc lattice was redesigned to acheive the lower emittance for crab waist scheme.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR010
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THPOR012	Dynamic Aperture Study of the CEPC Main Ring with Interaction Region	3795
	Y. Wang, S. Bai, T.J. Bian, J. Gao, H. Geng, D. Wang, Y. Zhang IHEP, Beijing, People's Republic of China F. Su Institute of High Energy Physics (IHEP), People's Republic of China
	CEPC is a Circular Electron and Positron Collider proposed by China to mainly study the Higgs boson. In order to achieve factory luminosity, a strong focusing system and low-emittance are required. A momentum acceptance as large as 2\% is also required to get a reasonable beam lifetime. This is one of the key issues of the CEPC accelerator physics. In this paper, the optics design of the interaction region and the optimization of dynamic aperture for the whole ring (single ring scheme) will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR012
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THPOR017	Dynamic Aperture Optimization at CEPC with Pretzel Orbit	3808
	H. Geng, S. Bai, X. Cui, Z. Duan, J. Gao, Y.Y. Guo, Y.M. Peng, Q. Qin, D. Wang, N. Wang, Y. Wang, G. Xu, Y. Yue, Y. Zhang IHEP, Beijing, People's Republic of China W. Chou Fermilab, Batavia, Illinois, USA F. Su Institute of High Energy Physics (IHEP), People's Republic of China
	A preliminary design of the CEPC ring with pretzel orbit will be presented. The ring and pretzel orbit will be designed for 50 bunches, as required in the CEPC Pre-CDR. The linear optics, as well as the non-linear chromaticity compensation with the presence of pretzel orbit will be described. Different phase advance difference between the long and short straight sections, have been tried to optimize the dynamic aperture, the results will be shown in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR017
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Paper

Title

Page

Emittance Measurement with Wire Scanners at C-ADS Injector-I

910

H. Geng, C. Meng, Y.F. Sui, F. Yan, L. Yu, Y.L. Zhao
IHEP, Beijing, People's Republic of China

The transverse emittance at C-ADS injector-I has been measured by the wire scanners at the Medium Energy Beam Transport-I (MEBT1). We have studied the effect of different fitting methods for obtaining the beam sizes on the emittance result, the result will be presented in this paper. The validation study of the quad-scan method with the presence of space charge effect at 10 mA will also be shown, and finally the quad-scan results will be compared with the multi-wire results.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY027

Export •

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

MOPOY030

Superconducting Cavity Phase and Amplitude Measurement in Low Energy Accelerating Section

919

C. Meng, H. Geng, F. Yan, Y.L. Zhao
IHEP, Beijing, People's Republic of China

Superconducting linear accelerator is the tendency in linac design with the development of superconducting RF technology. Superconducting cavities used as accelerating section in low energy Hadron linac are more and more common. The 5MeV test stand of CADS accelerator Injector I is composed of an ion source, a LEBT, a 325MHz RFQ, a MEBT, a cryogenic module (CM1) of seven SC spoke cavities (β=0.12) , seven SC solenoids, seven cold BPMs and a beam dump. The phase and amplitude setting of superconducting cavity are very important at the operation of accelerator, so beam based measurement of cavity phase and amplitude is necessary. Beam based phase scan is the most simple and effective method. Because the significant velocity changes in superconducting cavity at low energy section, the effective voltage is changing with cavity phase, meanwhile the synchronous phase is non-linear with LLRF phase. Above two problem make the cavity phase determination difficult. New date fitting method is proposed to solve these problem in this paper. Some measurements of spoke cavities in the CADS CM1 are also presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY030

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MOPOY031

Emittance Measurement with Double-Slit Method in CADS Injector-I

922

C. Meng, H. Geng, Z. Xue, F. Yan, L. Yu, Y.L. Zhao
IHEP, Beijing, People's Republic of China

The C-ADS accelerator is a CW (Continuous-Wave) proton linac with 1.5 GeV in beam energy, 10 mA in beam current, and 15 MW in beam power. CADS Injector-I accelerator is a 10-mA 10-MeV CW proton linac, which uses a 3.2-MeV normal conducting 4-Vane RFQ and superconducting single-spoke cavities for accelerating. The 5MeV test stand of CADS accelerator Injector I is composed of an ion source, a LEBT, a 325MHz RFQ, a MEBT, a cryogenic module (CM1) of seven SC spoke cavities (β=0.12) , seven SC solenoids, seven cold BPMs and a beam dump. Emittance measurement is very important for the understanding of beam behavior and matching to the next accelerating section. Detailed emittance measurement with double-slit method after CM1 are presented in this paper.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY031

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MOPOY032

Beam Twiss Measurement With Ws Including Space Charge Effect

925

Y.L. Zhao, H. Geng, C. Meng, F. Yan
IHEP, Beijing, People's Republic of China

Wire Scanners (WS) are used to measure beam profile and calculate the transverse Twiss parameters at the entrance of MEBT1 in the CADS injector I test stand. As to data process, the traditional method with transfer map doesn't consider the space charge effect. But, as we know, space charge effect can't be neglected for high intensity accelerators. In this paper, optimization algorithm is used in beam emittance measurement.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY032

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WEOBA02

Commissioning of the China-ADS Injector-I Testing Facility

2048

F. Yan, J.S. Cao, Y.L. Chi, R. Ge, H. Geng, S. Gu, D.Z. Guo, T.M. Huang, X. Jing, H. Li, R.L. Liu, F. Long, C. Meng, H.F. Ouyang, W.M. Pan, Q.L. Peng, Y.F. Sui, J.L. Wang, S.C. Wang, Z. Xue, Q. Ye, Y.L. Zhao
IHEP, Beijing, People's Republic of China

The 10 MeV accelerator-driven subcritical system (ADS) Injector I test stand at Institute of High Energy Physics (IHEP) is a testing facility dedicated to demonstrate one of the two injector design schemes [Injector Scheme-I, which works at 325 MHz], for the ADS project in China. The ion source was installed since April of 2014, periods of commissioning are regularly scheduled between installation phases of the rest of the injector. 6.05 MeV proton energy has been achieved with average beam current of 10 mA by 7 SC spoke cavities at present. This contribution reports the details of the commissioning results together with the challenges of the CW machine commissioning.

Slides WEOBA02 [5.243 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOBA02

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THPOR009

Cepc Partial Double Ring Lattice Design

3785

F. Su
Institute of High Energy Physics (IHEP), People's Republic of China
S. Bai, T.J. Bian, Z. Duan, J. Gao, H. Geng, D. Wang, Y. Wang, M. Xiao, G. Xu, Y. Zhang
IHEP, Beijing, People's Republic of China

In this paper, we introduced the layout and lattice design of Circular-Electron-Positron-Collider (CEPC) partial double ring (PDR) scheme. The baseline design of CEPC is a single beam-pipe electron positron collider, which has to adopt pretzel orbit scheme. And it is not suitable to serve as a high luminosity Z factory. If we choose partial double ring scheme, we can get a higher luminosity with lower power and be suitable to serve as a high luminosity Z factory. In this paper, we discussed the details of CEPC partial double ring lattice design and showed the dynamic aperture study and optimization.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR009

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THPOR010

CEPC Parameter Choice and Partial Double Ring Design

3788

D. Wang, S. Bai, T.J. Bian, X. Cui, Z. Duan, J. Gao, H. Geng, Y.Y. Guo, Q. Qin, N. Wang, Y. Wang, M. Xiao, J.Y. Zhai, C. Zhang, Y. Zhang
IHEP, Beijing, People's Republic of China
W. Chou
Fermilab, Batavia, Illinois, USA
F. Su
Institute of High Energy Physics (IHEP), People's Republic of China

Funding: Work supported by the National Foundation of Natural Sciences (11505198 and 11575218)
In order to avoid the pretzel orbit, CEPC is proposed to use partial double ring scheme in CDR. Based on crab waist scheme, we hope to either increase the luminosity with same beam power as Pre-CDR, or reduce the beam power while keeping the same luminosity in Pre-CDR. FFS with crab sextupoles has been developed and the arc lattice was redesigned to acheive the lower emittance for crab waist scheme.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR010

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THPOR012

Dynamic Aperture Study of the CEPC Main Ring with Interaction Region

3795

Y. Wang, S. Bai, T.J. Bian, J. Gao, H. Geng, D. Wang, Y. Zhang
IHEP, Beijing, People's Republic of China
F. Su
Institute of High Energy Physics (IHEP), People's Republic of China

CEPC is a Circular Electron and Positron Collider proposed by China to mainly study the Higgs boson. In order to achieve factory luminosity, a strong focusing system and low-emittance are required. A momentum acceptance as large as 2\% is also required to get a reasonable beam lifetime. This is one of the key issues of the CEPC accelerator physics. In this paper, the optics design of the interaction region and the optimization of dynamic aperture for the whole ring (single ring scheme) will be presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR012

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

THPOR017

Dynamic Aperture Optimization at CEPC with Pretzel Orbit

3808

H. Geng, S. Bai, X. Cui, Z. Duan, J. Gao, Y.Y. Guo, Y.M. Peng, Q. Qin, D. Wang, N. Wang, Y. Wang, G. Xu, Y. Yue, Y. Zhang
IHEP, Beijing, People's Republic of China
W. Chou
Fermilab, Batavia, Illinois, USA
F. Su
Institute of High Energy Physics (IHEP), People's Republic of China

A preliminary design of the CEPC ring with pretzel orbit will be presented. The ring and pretzel orbit will be designed for 50 bunches, as required in the CEPC Pre-CDR. The linear optics, as well as the non-linear chromaticity compensation with the presence of pretzel orbit will be described. Different phase advance difference between the long and short straight sections, have been tried to optimize the dynamic aperture, the results will be shown in this paper.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR017

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