HB2012 - List of Authors (Xu, S.Y.)

Paper

Title

Page

Beam Losses due to the Foil Scattering for CSNS/RCS

78

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

For the Rapid Cycling Synchrotron of China Spallation Neutron Source (CSNS/RCS), the stripping foil scattering generates the beam halo and gives rise to additional beam losses during the injection process. The interaction between the proton beam and the stripping foil was discussed and the foil scattering was studied. A simple model and the realistic situation of the foil scattering were considered. By using the codes ORBIT and FLUKA, the multi-turn phase space painting injection process with the stripping foil scattering for CSNS/RCS was simulated and the beam losses due to the foil scattering were obtained.

MOP216

The Design Study on the Longitudinal Beam Dynamics for CSNS/RCS

89

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

Rapid Cycling Synchrotron (RCS) is the key part of China Spallation Neutron Source (CSNS) accelerators. The RCS accumulates and accelerates 80 MeV beam from linac to 1.6 GeV. The particle number is 1.56·10¹³ for each pulse, with repetition rate of 25 Hz. In the RCS, longitudinal beam dynamics plays a crucial role in achieving high intensity beam with low beam loss. Longitudinal parameters are studied and optimized for efficient RF trapping of the beam in the longitudinal phase space. Beam performance is investigated by particle tracking simulations. Beam dynamic issues related to the high order mode induced by the RF generator are studied with a new developed code. Primary study on the adoption of dual harmonic cavity for higher beam power is also addressed.

THO1A02

Effects of Magnetic Field Tracking Errors and Space Charge on Beam Dynamics at CSNS/RCS

484

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

The China Spallation Neutron Source (CSNS) is an accelerator-based facility. It operates at 25 Hz repetition rate with an design beam power of 100 kW. CSNS consists of a 1.6-GeV Rapid Cycling Synchrotron (RCS) and a 80-MeV linac. The lattice of the CSNS/RCS is triplet based four-fold structure. The preferred working points of CSNS/RCS are (4.86, 4.78) which can avoid the major low-order structure resonances. But because of the chromatic tune shift, space-charge incoherent tune shift and the tune shift caused by magnetic field tracking errors between the quadrupoles and the dipoles, some structure resonances are unavoidable. The chromaticity, space charge effects and magnetic field tracking errors can also induce beta function distortion, and influence the transverse acceptance and the collimation efficiency of the collimation system. In this paper we show results of space-charge simulations introducing magnetic field tracking errors and discuss the combined effects of chromaticity, magnetic field tracking errors and space charge on the beam dynamics for CSNS/RCS.

Slides THO1A02 [1.613 MB]

Paper	Title	Page
MOP213	Beam Losses due to the Foil Scattering for CSNS/RCS	78
	M.Y. Huang, N. Wang, S. Wang, S.Y. Xu IHEP, Beijing, People's Republic of China
	For the Rapid Cycling Synchrotron of China Spallation Neutron Source (CSNS/RCS), the stripping foil scattering generates the beam halo and gives rise to additional beam losses during the injection process. The interaction between the proton beam and the stripping foil was discussed and the foil scattering was studied. A simple model and the realistic situation of the foil scattering were considered. By using the codes ORBIT and FLUKA, the multi-turn phase space painting injection process with the stripping foil scattering for CSNS/RCS was simulated and the beam losses due to the foil scattering were obtained.

MOP216	The Design Study on the Longitudinal Beam Dynamics for CSNS/RCS	89
	N. Wang, M.Y. Huang, Y. Li, S. Wang, S.Y. Xu, Y.S. Yuan IHEP, Beijing, People's Republic of China
	Rapid Cycling Synchrotron (RCS) is the key part of China Spallation Neutron Source (CSNS) accelerators. The RCS accumulates and accelerates 80 MeV beam from linac to 1.6 GeV. The particle number is 1.56·10¹³ for each pulse, with repetition rate of 25 Hz. In the RCS, longitudinal beam dynamics plays a crucial role in achieving high intensity beam with low beam loss. Longitudinal parameters are studied and optimized for efficient RF trapping of the beam in the longitudinal phase space. Beam performance is investigated by particle tracking simulations. Beam dynamic issues related to the high order mode induced by the RF generator are studied with a new developed code. Primary study on the adoption of dual harmonic cavity for higher beam power is also addressed.

THO1A02	Effects of Magnetic Field Tracking Errors and Space Charge on Beam Dynamics at CSNS/RCS	484
	S.Y. Xu, N. Wang, S. Wang IHEP, Beijing, People's Republic of China
	The China Spallation Neutron Source (CSNS) is an accelerator-based facility. It operates at 25 Hz repetition rate with an design beam power of 100 kW. CSNS consists of a 1.6-GeV Rapid Cycling Synchrotron (RCS) and a 80-MeV linac. The lattice of the CSNS/RCS is triplet based four-fold structure. The preferred working points of CSNS/RCS are (4.86, 4.78) which can avoid the major low-order structure resonances. But because of the chromatic tune shift, space-charge incoherent tune shift and the tune shift caused by magnetic field tracking errors between the quadrupoles and the dipoles, some structure resonances are unavoidable. The chromaticity, space charge effects and magnetic field tracking errors can also induce beta function distortion, and influence the transverse acceptance and the collimation efficiency of the collimation system. In this paper we show results of space-charge simulations introducing magnetic field tracking errors and discuss the combined effects of chromaticity, magnetic field tracking errors and space charge on the beam dynamics for CSNS/RCS.
	Slides THO1A02 [1.613 MB]