The beam energy measurement system is significant and profit for both BES-III detector and BEPC-II accelerator. The detection of the high energy scattering photons is realized by virtue of the Compton backscattering p...The beam energy measurement system is significant and profit for both BES-III detector and BEPC-II accelerator. The detection of the high energy scattering photons is realized by virtue of the Compton backscattering principle. Many advanced techniques and precise instruments are employed to acquire the highly accurate measurement of positron/electron beam energy. During five years’ running period, in order to satisfy the requirement of data taking and enhance the capacity of measurement itself, the upgradation of system is continued, which involves the components reformation of laser and optics subsystem, replacement of view-port of the laser to vacuum insertion subsystem, the usage of electric cooling system for high purity germanium detector, and the refinement of data acquisition and processing subsystem. The upgrading of system guarantees the smooth and effective measuring of beam energy at BEPC-II and accommodates the accurate offline energy values for further physics analysis at BES-III.展开更多
The beam energy measurement system is of great importance for both BEPC-II accelerator and BES-III detector. The system is based on measuring the energies of Compton back-scattered photons. In order to meet the requir...The beam energy measurement system is of great importance for both BEPC-II accelerator and BES-III detector. The system is based on measuring the energies of Compton back-scattered photons. In order to meet the requirements of data taking and improve the measurement accuracy, the system has continued to be upgraded, which involves the updating of laser and optics subsystems, replacement of a view-port of the laser to the vacuum insertion subsystem, the use of an electric cooling system for a high purity germanium detector, and improvement of the data acquisition and processing subsystem. The upgrade system guarantees the smooth and efficient measurement of beam energy at BEPC-II and enables accurate offline energy values for further physics analysis at BES-III.展开更多
Objective:This study is aimed at measuring the ripple of magnetic power supply of BEPCII and checking its effect to beam energy.Materials and methods:A sensor made of printed circuit board coils is designed and manufa...Objective:This study is aimed at measuring the ripple of magnetic power supply of BEPCII and checking its effect to beam energy.Materials and methods:A sensor made of printed circuit board coils is designed and manufactured.The sensor was inserted into a good area region of the magnetic field with the surface perpendicular to the field force lines.The change of the magnetic field would be detected according to Faraday’s law.Results:The experiment result indicates that the timedependent ripple of the magnetic field is in the magnitude of ppm.Conclusion:Such a small effect of the time-dependent ripplecan be negligibleto beam energy.展开更多
文摘The beam energy measurement system is significant and profit for both BES-III detector and BEPC-II accelerator. The detection of the high energy scattering photons is realized by virtue of the Compton backscattering principle. Many advanced techniques and precise instruments are employed to acquire the highly accurate measurement of positron/electron beam energy. During five years’ running period, in order to satisfy the requirement of data taking and enhance the capacity of measurement itself, the upgradation of system is continued, which involves the components reformation of laser and optics subsystem, replacement of view-port of the laser to vacuum insertion subsystem, the usage of electric cooling system for high purity germanium detector, and the refinement of data acquisition and processing subsystem. The upgrading of system guarantees the smooth and effective measuring of beam energy at BEPC-II and accommodates the accurate offline energy values for further physics analysis at BES-III.
基金Supported in part by National Natural Science Foundation of China(NSFC)(11375206,10775142,10825524,11125525,11235011)the Ministry of Science and Technology of China(2015CB856700,2015CB856705)+3 种基金State key laboratory of particle and detection and electronics and the CAS Center for Excellence in Particle Physics(CCEPP)the RFBR grant(14-02-00129-a)U.S.Department of Energy(DE-FG02-04ER41291,DE-FG02-05ER41374,DE-FG02-94ER40823,DESC0010118)U.S.National Science Foundation,part of this work related to the design of Zn Se viewports is supported by the Russian Science Foundation(14-50-00080)
文摘The beam energy measurement system is of great importance for both BEPC-II accelerator and BES-III detector. The system is based on measuring the energies of Compton back-scattered photons. In order to meet the requirements of data taking and improve the measurement accuracy, the system has continued to be upgraded, which involves the updating of laser and optics subsystems, replacement of a view-port of the laser to the vacuum insertion subsystem, the use of an electric cooling system for a high purity germanium detector, and improvement of the data acquisition and processing subsystem. The upgrade system guarantees the smooth and efficient measurement of beam energy at BEPC-II and enables accurate offline energy values for further physics analysis at BES-III.
文摘Objective:This study is aimed at measuring the ripple of magnetic power supply of BEPCII and checking its effect to beam energy.Materials and methods:A sensor made of printed circuit board coils is designed and manufactured.The sensor was inserted into a good area region of the magnetic field with the surface perpendicular to the field force lines.The change of the magnetic field would be detected according to Faraday’s law.Results:The experiment result indicates that the timedependent ripple of the magnetic field is in the magnitude of ppm.Conclusion:Such a small effect of the time-dependent ripplecan be negligibleto beam energy.
