The CBPM is a kind of monitor which is used for the measurement of beam transverse position. It is becoming increasingly popular due to its high potential in resolution performance. In theory, the resolution can reach...The CBPM is a kind of monitor which is used for the measurement of beam transverse position. It is becoming increasingly popular due to its high potential in resolution performance. In theory, the resolution can reach about 1 nanometer. In this paper, a rectangular CBPM is designed for it has better X-Y isolation than a cylindrical one. It has been simulated and measured, and the results agree with each other very well. The procedures and results for the simulation and the cold test will be shown later and it will be proved that this is a reliable method for the CBPM design.展开更多
The external Q （Qext） of the dipole mode is a key parameter of the Cavity Beam Position Monitor （CBPM）. It determines the amplitude and length of the dipole mode signal. In this paper, Qext of a CBPM whose wavegui...The external Q （Qext） of the dipole mode is a key parameter of the Cavity Beam Position Monitor （CBPM）. It determines the amplitude and length of the dipole mode signal. In this paper, Qext of a CBPM whose waveguides were open to the air was simulated and measured, and the results agreed with each other. Then four waveguide-to-coaxial cable adpaters were adjusted and assembled to the CBPM, and Qext remained unchanged. This progress provides a reliable method to evaluate Qext in the physics design without simulating the structurally complex adapters.展开更多
Purpose Higher-order modes(HOMs)may affect beam stability and refrigeration requirements of superconducting cavity such as the 166.6MHz SC cavity,which is studied at IHEP.Under certain conditions,beam-induced HOMs can...Purpose Higher-order modes(HOMs)may affect beam stability and refrigeration requirements of superconducting cavity such as the 166.6MHz SC cavity,which is studied at IHEP.Under certain conditions,beam-induced HOMs can accumulate sufficient energy to destabilize the beam or quench the superconducting cavities.Methods In order to limit these effects,we consider the use of the HOM coupler with HOMs extraction on the cutoff tubes of the 166.6MHz SC cavity.Results The HOM coupler can deeply suppress the fundamental mode and efficiently extract dangerous high-order modes.Conclusions In this paper,the HOM coupler design process is presented,which operates at 166.6MHz.The RF and thermal behavior are discussed.In order to verify the designs,a rapid prototype for the favored couplerwas fabricated and characterized on a low-power test stand.展开更多
文摘The CBPM is a kind of monitor which is used for the measurement of beam transverse position. It is becoming increasingly popular due to its high potential in resolution performance. In theory, the resolution can reach about 1 nanometer. In this paper, a rectangular CBPM is designed for it has better X-Y isolation than a cylindrical one. It has been simulated and measured, and the results agree with each other very well. The procedures and results for the simulation and the cold test will be shown later and it will be proved that this is a reliable method for the CBPM design.
文摘The external Q （Qext） of the dipole mode is a key parameter of the Cavity Beam Position Monitor （CBPM）. It determines the amplitude and length of the dipole mode signal. In this paper, Qext of a CBPM whose waveguides were open to the air was simulated and measured, and the results agreed with each other. Then four waveguide-to-coaxial cable adpaters were adjusted and assembled to the CBPM, and Qext remained unchanged. This progress provides a reliable method to evaluate Qext in the physics design without simulating the structurally complex adapters.
文摘Purpose Higher-order modes(HOMs)may affect beam stability and refrigeration requirements of superconducting cavity such as the 166.6MHz SC cavity,which is studied at IHEP.Under certain conditions,beam-induced HOMs can accumulate sufficient energy to destabilize the beam or quench the superconducting cavities.Methods In order to limit these effects,we consider the use of the HOM coupler with HOMs extraction on the cutoff tubes of the 166.6MHz SC cavity.Results The HOM coupler can deeply suppress the fundamental mode and efficiently extract dangerous high-order modes.Conclusions In this paper,the HOM coupler design process is presented,which operates at 166.6MHz.The RF and thermal behavior are discussed.In order to verify the designs,a rapid prototype for the favored couplerwas fabricated and characterized on a low-power test stand.
