IPAC2012 - List of Authors (Wang, N.)

Paper	Title	Page
MOPPD075	Optimization of the Collimation System for the CSNS/RCS	538
	N. Wang, M.Y. Huang, S. Wang, S.Y. Xu IHEP, Beijing, People's Republic of China
	Beam loss induced activation of the accelerator components is one of the primary concerns in designing a high intensity machine. The uncontrolled beam loss is required to be less than 1 W/m for hands-on maintenance of the machine. A two stage collimation system is designed in the Rapid Cycling Synchrotron (RCS) of the China Spallation Neutron Source (CSNS) to localize the beam losses in a restricted area. The parameters of the collimator are optimized in order to obtain high collimation efficiency. The final design of the collimation system is presented. The reliability of the collimation system is estimated for different working points and with closed orbit errors.

TUEPPB004	A Longitudinal Beam Dynamics Code for Proton Synchrotron	1119
	Y.S. Yuan, N. Wang, S. Wang, S.Y. Xu IHEP, Beijing, People's Republic of China
	The accelerator of China Spallation Neutron Source (CSNS) consists of an 80 MeV linac and a 1.6 GeV Rapid Cycling Synchrotron (RCS). Longitudinal beam dynamics study is one of the most important issues for RCS beam dynamics design. However, the existing codes cannot meet the requirement of longitudinal beam dynamics for CSNS/RCS. A new code has been developed for longitudinal beam dynamics design and simulation. The code can perform the voltage and phase curves design for non-sinusoidal magnetic field of dipole in an RCS cycle, with the fundamental RF mode and dual harmonic mode. The code can also be used for the beam simulation with longitudinal space charge effect, including the effects of higher order mode of RF cavities. By using the code, the longitudinal beam dynamics of CSNS/RCS was designed and optimized, and the simulation study with dual harmonics higher order modes of RF cavity was done, and the simulation results are presented.

WEPPR057	On the Single Bunch Longitudinal Collective Effects in BEPCII	3054
	D. Wang, Z. Duan, J. Gao, Y. Li, L. Wang, L. Wang, N. Wang IHEP, Beijing, People's Republic of China
	Funding: National Natural Science Foundation of China,project 11175192. In order to study the single bunch longitudinal instability in BEPCII, experiments on the bunch lengthening phenomenon were made. By analyzing the experimental data based on the Gao’s theory, the longitudinal loss factor for the bunch are obtained. Also, the total wake potential and the inductance of the machine are estimated.

THPPC012	Impedance Computation of Main Components in CSNS/RCS	3299
	Y. Li, L. Huang, Z.P. Li, Y.D. Liu, N. Wang, S. Wang IHEP, Beijing, People's Republic of China
	The rapid cycling synchrotron (RCS) of the China spallation neutron source (CSNS) is a high intensity proton accelerator. The study on the coupling impedance in the ring plays an important role in the stability of the beam. The impedance of the main vacuum components in the RCS ring, such as RF cavities, bellows, ports of vacuum pumps, collimator etc, was calculated by using numerical methods. Meantime, RF shielding of bellows, collimators and ports of vacuum pumps are considered. The impact of the busbar configuration on RF cavities and beams was estimated by impedance calculation.

Paper

Title

Page

Optimization of the Collimation System for the CSNS/RCS

538

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

Beam loss induced activation of the accelerator components is one of the primary concerns in designing a high intensity machine. The uncontrolled beam loss is required to be less than 1 W/m for hands-on maintenance of the machine. A two stage collimation system is designed in the Rapid Cycling Synchrotron (RCS) of the China Spallation Neutron Source (CSNS) to localize the beam losses in a restricted area. The parameters of the collimator are optimized in order to obtain high collimation efficiency. The final design of the collimation system is presented. The reliability of the collimation system is estimated for different working points and with closed orbit errors.

TUEPPB004

A Longitudinal Beam Dynamics Code for Proton Synchrotron

1119

Y.S. Yuan, N. Wang, S. Wang, S.Y. Xu
IHEP, Beijing, People's Republic of China

The accelerator of China Spallation Neutron Source (CSNS) consists of an 80 MeV linac and a 1.6 GeV Rapid Cycling Synchrotron (RCS). Longitudinal beam dynamics study is one of the most important issues for RCS beam dynamics design. However, the existing codes cannot meet the requirement of longitudinal beam dynamics for CSNS/RCS. A new code has been developed for longitudinal beam dynamics design and simulation. The code can perform the voltage and phase curves design for non-sinusoidal magnetic field of dipole in an RCS cycle, with the fundamental RF mode and dual harmonic mode. The code can also be used for the beam simulation with longitudinal space charge effect, including the effects of higher order mode of RF cavities. By using the code, the longitudinal beam dynamics of CSNS/RCS was designed and optimized, and the simulation study with dual harmonics higher order modes of RF cavity was done, and the simulation results are presented.

WEPPR057

On the Single Bunch Longitudinal Collective Effects in BEPCII

3054

D. Wang, Z. Duan, J. Gao, Y. Li, L. Wang, L. Wang, N. Wang
IHEP, Beijing, People's Republic of China

Funding: National Natural Science Foundation of China,project 11175192.
In order to study the single bunch longitudinal instability in BEPCII, experiments on the bunch lengthening phenomenon were made. By analyzing the experimental data based on the Gao’s theory, the longitudinal loss factor for the bunch are obtained. Also, the total wake potential and the inductance of the machine are estimated.

THPPC012

Impedance Computation of Main Components in CSNS/RCS

3299

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

The rapid cycling synchrotron (RCS) of the China spallation neutron source (CSNS) is a high intensity proton accelerator. The study on the coupling impedance in the ring plays an important role in the stability of the beam. The impedance of the main vacuum components in the RCS ring, such as RF cavities, bellows, ports of vacuum pumps, collimator etc, was calculated by using numerical methods. Meantime, RF shielding of bellows, collimators and ports of vacuum pumps are considered. The impact of the busbar configuration on RF cavities and beams was estimated by impedance calculation.