2011 Particle Accelerator Conference - List of Authors (Feng, G.)

Paper	Title	Page
TUP190	Upgrade of the APS Booster Synchrotron Magnet Ramp	1181
	C. Yao, B. Deriy, G. Feng, H. Shang, J. Wang ANL, Argonne, USA
	Funding: Work supported by U.S. Department of Energy, Offices of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06-CH11357 The APS booster is a 7-GeV electron synchrotron with 0.5-second cycle time. Both voltage and current ramp modes were in the original design but only the voltage ramp has been commissioned. Two software-based ramp control programs are used to regulate the current waveform to a linear ramp. The system has been operated for user beam operations for many years. Some instability exists in the ramp correction that requires manual intervention from time to time by the operators. Sensitivity of magnet currents to external changes, such as AC line voltage, harmonic interference from the high-power rf system, etc., has been observed. In order to meet the increased single-bunch-charge requirement of the APS upgrade we need more flexible current ramps such as flat porches for injection and extraction and smooth transitions. Recent efforts to develop an energy-saving operation mode also call for ramp improvement. This paper presents test results of a workstation-based current regulation program and an FPGA-based implementation as a future upgrade.

TUP145	Introduction to HLSII Storage Ring Conventional Magnets	1100
	H. Zhang, G. Feng, W.W. Li, W. Li, J.J. Liang, L. Wang, S.C. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	HLS (Hefei Light Source) is a dedicated synchrotron radiation research facility, whose emittance is relatively large. In order to improve the performance of HLS, especially getting higher brilliance synchrotron radiation and increasing the number of straight section for insertion devices, an upgrade project named HLSII will be proceeded soon. The storage ring lattice comprises 8 dipoles, 32 quadrupoles and 32 combined function sextupoles. Design and analysis of the magnets are showed in the paper. the multipurpose combined function magnet is the first one designed and used in China. Mechanical design and fabrication procedures for the magnets are presented also.

WEP090	Simulation Study of Intrabeam Scattering in Low Emittance Ring	1639
	W. Fan, G. Feng, D.H. He, W. Li, L. Wang, S.C. Zhang, T. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	HALS(Hefei Advanced Light Source) is under designing dedicated to good coherence and high brightness at 1.5GeV. Low emittance is required to reach the design request. Due to the low energy and emittance with relative high bunch charge, intrabeam scattering effect will be very strong. It is worth accurately calculating to check if the design goal can be reached. Theoretic calculation based on Gaussian beam distribution doesn't warrant in strong IBS regime. In this paper we present the results of particle simulation study of intrabeam scattering effect on a temporary design lattice of HALS ring.

Paper

Title

Page

Upgrade of the APS Booster Synchrotron Magnet Ramp

1181

C. Yao, B. Deriy, G. Feng, H. Shang, J. Wang
ANL, Argonne, USA

Funding: Work supported by U.S. Department of Energy, Offices of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06-CH11357
The APS booster is a 7-GeV electron synchrotron with 0.5-second cycle time. Both voltage and current ramp modes were in the original design but only the voltage ramp has been commissioned. Two software-based ramp control programs are used to regulate the current waveform to a linear ramp. The system has been operated for user beam operations for many years. Some instability exists in the ramp correction that requires manual intervention from time to time by the operators. Sensitivity of magnet currents to external changes, such as AC line voltage, harmonic interference from the high-power rf system, etc., has been observed. In order to meet the increased single-bunch-charge requirement of the APS upgrade we need more flexible current ramps such as flat porches for injection and extraction and smooth transitions. Recent efforts to develop an energy-saving operation mode also call for ramp improvement. This paper presents test results of a workstation-based current regulation program and an FPGA-based implementation as a future upgrade.

TUP145

Introduction to HLSII Storage Ring Conventional Magnets

1100

H. Zhang, G. Feng, W.W. Li, W. Li, J.J. Liang, L. Wang, S.C. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

HLS (Hefei Light Source) is a dedicated synchrotron radiation research facility, whose emittance is relatively large. In order to improve the performance of HLS, especially getting higher brilliance synchrotron radiation and increasing the number of straight section for insertion devices, an upgrade project named HLSII will be proceeded soon. The storage ring lattice comprises 8 dipoles, 32 quadrupoles and 32 combined function sextupoles. Design and analysis of the magnets are showed in the paper. the multipurpose combined function magnet is the first one designed and used in China. Mechanical design and fabrication procedures for the magnets are presented also.

WEP090

Simulation Study of Intrabeam Scattering in Low Emittance Ring

1639

W. Fan, G. Feng, D.H. He, W. Li, L. Wang, S.C. Zhang, T. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

HALS(Hefei Advanced Light Source) is under designing dedicated to good coherence and high brightness at 1.5GeV. Low emittance is required to reach the design request. Due to the low energy and emittance with relative high bunch charge, intrabeam scattering effect will be very strong. It is worth accurately calculating to check if the design goal can be reached. Theoretic calculation based on Gaussian beam distribution doesn't warrant in strong IBS regime. In this paper we present the results of particle simulation study of intrabeam scattering effect on a temporary design lattice of HALS ring.