A 1.5 GHz passive third harmonic superconducting cavity was proposed to improve the beam quality and lifetime in the Shanghai Synchrotron Radiation Facility Phase-II beamline project.Lifetime improvement highly depend...A 1.5 GHz passive third harmonic superconducting cavity was proposed to improve the beam quality and lifetime in the Shanghai Synchrotron Radiation Facility Phase-II beamline project.Lifetime improvement highly depends on the resonant frequency of the passive third harmonic superconducting cavity.It is important that the operating frequency of the cavity is within the design range and the cavity has reasonable mechanical stability.A simulation method for the multiphysics coupled analysis has been developed based on the ANSYS code.Multiphysics coupled simulations have been performed under different conditions,such as etching,evacuation,cooling,and preloading.Analyses of mechanical modes and structural stress have been executed.A possible stiffening ring method for the two-cell superconducting niobium cavity has been investigated.In this paper,we present a multiphysics coupled analysis of the third harmonic cavity using a finite element analysis code.The results of the analysis show that a reliable frequency for the cavity after electron beam welding is 1498.033 MHz,and the corresponding frequency of the pre-tuning goal is 1496.163 MHz.A naked cavity is a reasonable option based on structural stress and mechanical modal analyses.A frequency range of±500 kHz and limiting tolerable displacement of±0.35 mm are proposed for the design of the frequency tuner.展开更多
Peking University is developing a 1.3 GHz superconducting accelerating section highpower THz free- electron laser for the China Academy of Engineering Physics （CAEP）. A compact fast/slow tuner has been developed by ...Peking University is developing a 1.3 GHz superconducting accelerating section highpower THz free- electron laser for the China Academy of Engineering Physics （CAEP）. A compact fast/slow tuner has been developed by the Institute of High Energy Physics （IHEP） for the accelerating section to control Lorentz detuning, compensate for beam loading effect, microphonics and liquid helium pressure fluctuations. The tuner design, warm test and cold test of the first prototype are presented, which has a guiding significance for the manufazture of the formal tuner and cryomodule assembly.展开更多
The tuning system plays a very important role when a superconducting cavity is in operation. It cooperates with other control loops to adjust the cavity frequency with high precision, reduce the reflection power, guar...The tuning system plays a very important role when a superconducting cavity is in operation. It cooperates with other control loops to adjust the cavity frequency with high precision, reduce the reflection power, guarantee the stability of beam, and ensure the safety of the superconducting cavity. This paper focuses mainly on the tuning system working principle, the working state and problems that Beijing Electron Positron Collider （BEPC ｜I ） has encountered during operation.展开更多
基金supported by the National Natural Science Foundation of China(No.11335014)
文摘A 1.5 GHz passive third harmonic superconducting cavity was proposed to improve the beam quality and lifetime in the Shanghai Synchrotron Radiation Facility Phase-II beamline project.Lifetime improvement highly depends on the resonant frequency of the passive third harmonic superconducting cavity.It is important that the operating frequency of the cavity is within the design range and the cavity has reasonable mechanical stability.A simulation method for the multiphysics coupled analysis has been developed based on the ANSYS code.Multiphysics coupled simulations have been performed under different conditions,such as etching,evacuation,cooling,and preloading.Analyses of mechanical modes and structural stress have been executed.A possible stiffening ring method for the two-cell superconducting niobium cavity has been investigated.In this paper,we present a multiphysics coupled analysis of the third harmonic cavity using a finite element analysis code.The results of the analysis show that a reliable frequency for the cavity after electron beam welding is 1498.033 MHz,and the corresponding frequency of the pre-tuning goal is 1496.163 MHz.A naked cavity is a reasonable option based on structural stress and mechanical modal analyses.A frequency range of±500 kHz and limiting tolerable displacement of±0.35 mm are proposed for the design of the frequency tuner.
基金Supported by the 500 MHz superconducting cavity electromechanical tuning system(Y190KFEOHD)NSAF(11176003)National Major Scientific Instrument and Equipment Development projects(2011YQ130018)
文摘Peking University is developing a 1.3 GHz superconducting accelerating section highpower THz free- electron laser for the China Academy of Engineering Physics （CAEP）. A compact fast/slow tuner has been developed by the Institute of High Energy Physics （IHEP） for the accelerating section to control Lorentz detuning, compensate for beam loading effect, microphonics and liquid helium pressure fluctuations. The tuner design, warm test and cold test of the first prototype are presented, which has a guiding significance for the manufazture of the formal tuner and cryomodule assembly.
基金Supported by 500 MHz Superconducting Cavity Electromechanical Tuning System （Y190KFEOHD）
文摘The tuning system plays a very important role when a superconducting cavity is in operation. It cooperates with other control loops to adjust the cavity frequency with high precision, reduce the reflection power, guarantee the stability of beam, and ensure the safety of the superconducting cavity. This paper focuses mainly on the tuning system working principle, the working state and problems that Beijing Electron Positron Collider （BEPC ｜I ） has encountered during operation.
