IPAC2016 - List of Authors (Meng, C.)

Paper	Title	Page
MOPMB032	A New Fault Recovery Mechanism for Superconducting Cavity Failure in C-ADS	158
	Z. Xue, J.P. Dai, C. Meng IHEP, Beijing, People's Republic of China
	For proton linear accelerators used in applications such as C-ADS, due to the nature of the operation, it is essential to have beam failures at the rate several orders of magnitude lower than usual performance of similar accelerators. A fault-tolerant mechanism should be mandatorily imposed in order to maintain short recovery time, high uptime and extremely low frequency of beam loss. This paper proposes an innovative and challenging way for compensation and rematch of cavity failure using fast electronic devices and Field Programmable Gate Array (FPGA) instead of embedded computers to complete the computation of beam dynamics. Due to the high arithmetic-computing-speed, good portability and repeatability, it is possible to realize calculation and re-adjustment online. In order to achieve the goal of instantaneous compensation and rematch, an advanced hardware design methodology including high-level synthesis and an improved genetic algorithm will be used.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB032
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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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Paper

Title

Page

A New Fault Recovery Mechanism for Superconducting Cavity Failure in C-ADS

158

Z. Xue, J.P. Dai, C. Meng
IHEP, Beijing, People's Republic of China

For proton linear accelerators used in applications such as C-ADS, due to the nature of the operation, it is essential to have beam failures at the rate several orders of magnitude lower than usual performance of similar accelerators. A fault-tolerant mechanism should be mandatorily imposed in order to maintain short recovery time, high uptime and extremely low frequency of beam loss. This paper proposes an innovative and challenging way for compensation and rematch of cavity failure using fast electronic devices and Field Programmable Gate Array (FPGA) instead of embedded computers to complete the computation of beam dynamics. Due to the high arithmetic-computing-speed, good portability and repeatability, it is possible to realize calculation and re-adjustment online. In order to achieve the goal of instantaneous compensation and rematch, an advanced hardware design methodology including high-level synthesis and an improved genetic algorithm will be used.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB032

Export •

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

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

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

Export •

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

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

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

Export •

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