HB2012 - List of Authors (Wang, J.Q.)

Paper	Title	Page
MOP212	Simulation of Longitudinal Beam Instability caused by HOMs	73
	P. Cheng, Z. Li, J.Y. Tang, J.Q. Wang IHEP, Beijing, People's Republic of China
	Superconducting cavities are employed in C-ADS linac to accelerate 10mA CW proton beams from 3.2 MeV to 1.5 GeV. High order modes in superconducting cavities are found by using the simulation tools CST and HFSS, then power dissipation caused by HOMs have been investigated, it is indicated that the Qext should not go beyond 10⁷} in order to limit the additional heat load. Beam instabilities caused by high order modes in elliptical cavity sections are investigated using the code offered by Dr. Jean-Luc Biarrotte (CNRS, IPN Orsay, France). Beam errors, linac errors and high order modes frequency spread are investigated in detail. It shows that the monopole modes do not affect the proton beam critically and need no HOM couplers (Q_ext=10⁵}) if high order modes frequency spread is more than 100 kHz.

Paper

Title

Page

Simulation of Longitudinal Beam Instability caused by HOMs

73

P. Cheng, Z. Li, J.Y. Tang, J.Q. Wang
IHEP, Beijing, People's Republic of China

Superconducting cavities are employed in C-ADS linac to accelerate 10mA CW proton beams from 3.2 MeV to 1.5 GeV. High order modes in superconducting cavities are found by using the simulation tools CST and HFSS, then power dissipation caused by HOMs have been investigated, it is indicated that the Qext should not go beyond 10⁷} in order to limit the additional heat load. Beam instabilities caused by high order modes in elliptical cavity sections are investigated using the code offered by Dr. Jean-Luc Biarrotte (CNRS, IPN Orsay, France). Beam errors, linac errors and high order modes frequency spread are investigated in detail. It shows that the monopole modes do not affect the proton beam critically and need no HOM couplers (Q_ext=10⁵}) if high order modes frequency spread is more than 100 kHz.