IPAC2011 - List of Authors (Wang, S.)

Paper

Title

Page

Study on Resistive Wall Instability in CSNS/RCS

745

L. Huang, Y.D. Liu, S. Wang
IHEP Beijing, Beijing, People's Republic of China

Rapid Cycling Synchrotron of the China Spallation Neutron Source is a high intensity proton accelerator, with average beam power of 100kW. The collective effects caused by the coupling impedance may be the limit to beam power. The impedance estimation for components on beam line shows that the resistive wall impedance and its instability are more serious than any others. Based on the impedance budget, the instability is theoretically estimated. And a simple resistive wall wake field model is used to simulate the bunch oscillation and the growth rate instability. In this model, the continuous resistive wall wake field is equivalent to a point wake field and long bunch is sliced into many micro-bunches. By tracking the dynamics of the macro-bunches, the transverse growth rate are obtained and the result are analyzed.

WEPS011

Application of Orbit Response Matrix Method at CSNS/RCS

2505

Y.W. An, S. Wang
IHEP Beijing, Beijing, People's Republic of China

The China Spallation Neutron Source(CSNS) consists of a low energy linac and a high energy Rapid Cycling Synchrotron(RCS). RCS accumulates 80MeV beam and accelerates to 1.6GeV with 25Hz repetition rate and the average extraction beam power is 100kW. For controlling beam loss, the closed orbit should be adjusted as flexible as possible. The orbit response matrix(ORM) method is applied to correct the closed orbit distortion in RCS. The simulation study was made by using the code Linear Optics from Closed Orbit(LOCO) for CSNS/RCS, and the results of simulation study are presented.

WEPS099

Physics Design of CSNS RCS Injection and Extraction System

2739

J. Qiu, N. Huang, J. Tang, S. Wang
IHEP Beijing, Beijing, People's Republic of China

In this paper, the injection and extraction system design for CSNS RCS are discussed. The injection system is designed to place all the injection devices in one uninterrupted long drift in one of the four dispersion free straight sections. Painting bumper magnets are used for both horizontal and vertical phase space painting. The beam extraction process from the CSNS RCS is a single turn two step process, requiring a group of kickers and a Lambertson septum magnet.

TUXA01

Status and Challenges of the China Spallation Neutron Source

889

S. Fu, H. Chen, Y.W. Chen, Y.L. Chi, H. Dong, L. Dong, S.X. Fang, K.X. Huang, W. Kang, J. Li, L. Ma, H.F. Ouyang, H. Qu, H. Sun, J. Tang, C.H. Wang, Q.B. Wang, S. Wang, T.G. Xu, Z.X. Xu, X. Yin, C. Zhang, J. Zhang
IHEP Beijing, Beijing, People's Republic of China

The accelerator complex of China Spallation Neutron Source (CSNS) mainly consists of an H⁻ linac of 80 MeV and a rapid-cycling synchrotron of 1.6 GeV. It operates at 25 Hz repetition rate with an initial proton beam power of 100 kW and is upgradeable to 500kW. The project will start construction in the middle of 2011 with a construction period of 6.5 years. The CSNS accelerator is the first large-scale, high-power accelerator project to be constructed in China and thus we are facing a lot of challenges. This paper presents the current status of CSNS project and summarizes the technology development during the past several years.

Slides TUXA01 [3.444 MB]

THPS041

Design of Beam Transport Line from RCS to Target for CSNS

3514

W.B. Liu, N. Huang, J. Qiu, J. Tang, S. Wang, G. Xu
IHEP Beijing, Beijing, People's Republic of China

China Spallation Neutron Source (CSNS) uses the high energy proton beam to strike the Tungsten target to generate neutrons through spallation reaction. The proton beam is extracted from the Rapid Cycling Synchrotron (RCS), whose beam power reaches 100 kW. For the sake of target lifetime, beam distribution at the target surface is required as uniform as possible. Nonlinear beam density redistribution method with two octupole magnets has been studied. Also some simulation and theoretical calculation have been done. According to the simulation result, the beam density at the target is optimized and the beam loss is under control.

THPS042

Feasibility Studies of the Foil Scattering Extraction in CSNS/RCS

3517

N. Wang, M.Y. Huang, N. Huang, S. Wang
IHEP Beijing, Beijing, People's Republic of China

A slow extraction based on foil scattering was suggested in the rapid cycling synchrotron of China Spallation Neutron Source for particle calibration. Protons with large scattering angle will be extracted during 2 ms at the end of each beam cycle, via a carbon foil. The feasibility of the extraction scheme is investigated. The extraction efficiency is studied by both single turn and multi-turn simulations with FLUKA and ORBIT, respectively. Beam losses due to multiple scattering to the downstream components are predicted.

Paper	Title	Page
MOPS060	Study on Resistive Wall Instability in CSNS/RCS	745
	L. Huang, Y.D. Liu, S. Wang IHEP Beijing, Beijing, People's Republic of China
	Rapid Cycling Synchrotron of the China Spallation Neutron Source is a high intensity proton accelerator, with average beam power of 100kW. The collective effects caused by the coupling impedance may be the limit to beam power. The impedance estimation for components on beam line shows that the resistive wall impedance and its instability are more serious than any others. Based on the impedance budget, the instability is theoretically estimated. And a simple resistive wall wake field model is used to simulate the bunch oscillation and the growth rate instability. In this model, the continuous resistive wall wake field is equivalent to a point wake field and long bunch is sliced into many micro-bunches. By tracking the dynamics of the macro-bunches, the transverse growth rate are obtained and the result are analyzed.

WEPS011	Application of Orbit Response Matrix Method at CSNS/RCS	2505
	Y.W. An, S. Wang IHEP Beijing, Beijing, People's Republic of China
	The China Spallation Neutron Source(CSNS) consists of a low energy linac and a high energy Rapid Cycling Synchrotron(RCS). RCS accumulates 80MeV beam and accelerates to 1.6GeV with 25Hz repetition rate and the average extraction beam power is 100kW. For controlling beam loss, the closed orbit should be adjusted as flexible as possible. The orbit response matrix(ORM) method is applied to correct the closed orbit distortion in RCS. The simulation study was made by using the code Linear Optics from Closed Orbit(LOCO) for CSNS/RCS, and the results of simulation study are presented.

WEPS099	Physics Design of CSNS RCS Injection and Extraction System	2739
	J. Qiu, N. Huang, J. Tang, S. Wang IHEP Beijing, Beijing, People's Republic of China
	In this paper, the injection and extraction system design for CSNS RCS are discussed. The injection system is designed to place all the injection devices in one uninterrupted long drift in one of the four dispersion free straight sections. Painting bumper magnets are used for both horizontal and vertical phase space painting. The beam extraction process from the CSNS RCS is a single turn two step process, requiring a group of kickers and a Lambertson septum magnet.

TUXA01	Status and Challenges of the China Spallation Neutron Source	889
	S. Fu, H. Chen, Y.W. Chen, Y.L. Chi, H. Dong, L. Dong, S.X. Fang, K.X. Huang, W. Kang, J. Li, L. Ma, H.F. Ouyang, H. Qu, H. Sun, J. Tang, C.H. Wang, Q.B. Wang, S. Wang, T.G. Xu, Z.X. Xu, X. Yin, C. Zhang, J. Zhang IHEP Beijing, Beijing, People's Republic of China
	The accelerator complex of China Spallation Neutron Source (CSNS) mainly consists of an H⁻ linac of 80 MeV and a rapid-cycling synchrotron of 1.6 GeV. It operates at 25 Hz repetition rate with an initial proton beam power of 100 kW and is upgradeable to 500kW. The project will start construction in the middle of 2011 with a construction period of 6.5 years. The CSNS accelerator is the first large-scale, high-power accelerator project to be constructed in China and thus we are facing a lot of challenges. This paper presents the current status of CSNS project and summarizes the technology development during the past several years.
	Slides TUXA01 [3.444 MB]

THPS041	Design of Beam Transport Line from RCS to Target for CSNS	3514
	W.B. Liu, N. Huang, J. Qiu, J. Tang, S. Wang, G. Xu IHEP Beijing, Beijing, People's Republic of China
	China Spallation Neutron Source (CSNS) uses the high energy proton beam to strike the Tungsten target to generate neutrons through spallation reaction. The proton beam is extracted from the Rapid Cycling Synchrotron (RCS), whose beam power reaches 100 kW. For the sake of target lifetime, beam distribution at the target surface is required as uniform as possible. Nonlinear beam density redistribution method with two octupole magnets has been studied. Also some simulation and theoretical calculation have been done. According to the simulation result, the beam density at the target is optimized and the beam loss is under control.

THPS042	Feasibility Studies of the Foil Scattering Extraction in CSNS/RCS	3517
	N. Wang, M.Y. Huang, N. Huang, S. Wang IHEP Beijing, Beijing, People's Republic of China
	A slow extraction based on foil scattering was suggested in the rapid cycling synchrotron of China Spallation Neutron Source for particle calibration. Protons with large scattering angle will be extracted during 2 ms at the end of each beam cycle, via a carbon foil. The feasibility of the extraction scheme is investigated. The extraction efficiency is studied by both single turn and multi-turn simulations with FLUKA and ORBIT, respectively. Beam losses due to multiple scattering to the downstream components are predicted.