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 horizontal test for the BEPC 500 MHz spare cavity has been completed at IHEP. The maximum voltage of the cavity reached 2.17 MV, while Q 0 was 5.78 × 10^8 . The process and results of the high power horizonta...The horizontal test for the BEPC 500 MHz spare cavity has been completed at IHEP. The maximum voltage of the cavity reached 2.17 MV, while Q 0 was 5.78 × 10^8 . The process and results of the high power horizontal test are presented and discussed in this paper.展开更多
In the digital low level RF （LLRF） system of a circular （particle） accelerator, the RF field signal is usually down converted to a fixed intermediate frequency （IF）. The ratio of IF and sampling frequency determ...In the digital low level RF （LLRF） system of a circular （particle） accelerator, the RF field signal is usually down converted to a fixed intermediate frequency （IF）. The ratio of IF and sampling frequency determines the processing required, and differs in various LLRF systems. It is generally desirable to design a universally compatible architecture for different IFs with no change to the sampling frequency and algorithm. A new RF detection method based on a double heterodyne architecture for wide IF range has been developed, which achieves the high accuracy requirement of modern LLRF. In this paper, the relation of IF and phase error is systematically analyzed for the first time and verified by experiments. The effects of temperature drift for 16 h IF detection are inhibited by the amplitude and phase calibrations.展开更多
A 325 MHzβ=0.14 superconducting half-wave resonator prototype has been developed at the Institute of High Energy Physics, Beijing, which can be applied in the low energy section of continuous wave high current proton...A 325 MHzβ=0.14 superconducting half-wave resonator prototype has been developed at the Institute of High Energy Physics, Beijing, which can be applied in the low energy section of continuous wave high current proton linear accelerators. The electromagnetic design, multipacting simulation, mechanical optimization and fabrication are introduced in detail. Test results at room temperature and 4.2 K, and a comparison between measured and simulated results, are analyzed in this paper.展开更多
The Superconducting Radio Frequency （SRF） system of the upgrade project of the Beijing Electron Positron Collider （BEPCII） has been in operation for almost 8 years. During operation, many problems have been encoun...The Superconducting Radio Frequency （SRF） system of the upgrade project of the Beijing Electron Positron Collider （BEPCII） has been in operation for almost 8 years. During operation, many problems have been encountered, such as excessive heating of the power couplers, frequent beam trips during high intensity colliding, false arc interlock trigger and so on. Among them, some has been solved successfully, some have been alleviated. This paper will describe some experiences with BEPCII SRF system operation, including the symptoms, causes and solutions of problems.展开更多
A new tuner control system for spoke superconducting radio frequency（SRF） cavities has been developed and applied to cryomodule I of the C-ADS injector I at the Institute of High Energy Physics, Chinese Academy of S...A new tuner control system for spoke superconducting radio frequency（SRF） cavities has been developed and applied to cryomodule I of the C-ADS injector I at the Institute of High Energy Physics, Chinese Academy of Sciences. We have successfully implemented the tuner controller based on Programmable Logic Controller（PLC）for the first time and achieved a cavity tuning phase error of ±0.7？（about ±4 Hz peak to peak） in the presence of electromechanical coupled resonance. This paper presents preliminary experimental results based on the PLC tuner controller under proton beam commissioning.展开更多
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 Facility Repair Project of CAS (K71G710Y21)
文摘The horizontal test for the BEPC 500 MHz spare cavity has been completed at IHEP. The maximum voltage of the cavity reached 2.17 MV, while Q 0 was 5.78 × 10^8 . The process and results of the high power horizontal test are presented and discussed in this paper.
文摘In the digital low level RF （LLRF） system of a circular （particle） accelerator, the RF field signal is usually down converted to a fixed intermediate frequency （IF）. The ratio of IF and sampling frequency determines the processing required, and differs in various LLRF systems. It is generally desirable to design a universally compatible architecture for different IFs with no change to the sampling frequency and algorithm. A new RF detection method based on a double heterodyne architecture for wide IF range has been developed, which achieves the high accuracy requirement of modern LLRF. In this paper, the relation of IF and phase error is systematically analyzed for the first time and verified by experiments. The effects of temperature drift for 16 h IF detection are inhibited by the amplitude and phase calibrations.
文摘A 325 MHzβ=0.14 superconducting half-wave resonator prototype has been developed at the Institute of High Energy Physics, Beijing, which can be applied in the low energy section of continuous wave high current proton linear accelerators. The electromagnetic design, multipacting simulation, mechanical optimization and fabrication are introduced in detail. Test results at room temperature and 4.2 K, and a comparison between measured and simulated results, are analyzed in this paper.
文摘The Superconducting Radio Frequency （SRF） system of the upgrade project of the Beijing Electron Positron Collider （BEPCII） has been in operation for almost 8 years. During operation, many problems have been encountered, such as excessive heating of the power couplers, frequent beam trips during high intensity colliding, false arc interlock trigger and so on. Among them, some has been solved successfully, some have been alleviated. This paper will describe some experiences with BEPCII SRF system operation, including the symptoms, causes and solutions of problems.
基金Supported by Proton linac accelerator I of China Accelerator Driven sub-critical System(Y12C32W129)
文摘A new tuner control system for spoke superconducting radio frequency（SRF） cavities has been developed and applied to cryomodule I of the C-ADS injector I at the Institute of High Energy Physics, Chinese Academy of Sciences. We have successfully implemented the tuner controller based on Programmable Logic Controller（PLC）for the first time and achieved a cavity tuning phase error of ±0.7？（about ±4 Hz peak to peak） in the presence of electromechanical coupled resonance. This paper presents preliminary experimental results based on the PLC tuner controller under proton beam commissioning.
