Background High energy photon source(HEPS)is the fourth-generation light source,which uses a large number of highperformance insertion devices to generate synchrotron radiation.The control system is an important part ...Background High energy photon source(HEPS)is the fourth-generation light source,which uses a large number of highperformance insertion devices to generate synchrotron radiation.The control system is an important part of the insertion device(ID).Purpose Cryogenic permanent magnet undulator(CPMU)is one kind of IDs that works in liquid nitrogen temperature and ultra-high vacuum environment,and its control system is more difficult and complex than in-air ID.The design of the control system for CPMU will be introduced in detail.Method The sub-systems include high-precision magnetic gap control,safety protection,measurement and compensation of magnetic gap at cryogenic temperature and cryogenic temperature monitoring.Mature,reliable,stable technical schemes are designed to meet the technical specifications of sub-systems.Results The experiment results show that the magnetic gap motion accuracy can be controlled within 0.2–0.3μm under the step size of 1μm.The safety protection system has been tested in turn,and the predetermined protection can be achieved.The average value of magnetic gap cold contraction is 1.512 mm measured by optical micrometer,and the compensation is realized by software.The average temperature of the main magnet structure measured by the temperature sensors is 81.0 K,and the temperature gradient is 0.7 K/m.The temperature monitoring is reliable and stable.Conclusion The CPMU control system which is based on EPICS has been successfully applied to the CPMU prototype,and the test results have met the design specifications.展开更多
Introduction A novel type of pure permanent cryogenic Delta–Knot Undulator was developed at IHEP to supply a high flux of full adjustable polarization synchrotron radiation with low on-axis power density.This prototy...Introduction A novel type of pure permanent cryogenic Delta–Knot Undulator was developed at IHEP to supply a high flux of full adjustable polarization synchrotron radiation with low on-axis power density.This prototype was an active attempt and early exploration for future APPLE–Knot undulator,which will be used at high energy photon source(HEPS).Materials and methods There are several challenges to develop a cryogenic delta undulator,such as the complicated structure,the influence of large magnetic force,and the magnetic measurement difficulty due to the very small gap.In this paper,the mechanical design for overcoming these difficulties will be presented in detail.Conclusion A special hall measuring system is developed,and the preliminary results agree with the theoretical results.This undulator prototype will provide valuable experience for angle magnetization technology,intricate magnetic attraction structure design,and magnetic field measurement under closed small space.展开更多
A new stretched-wire system is built for a cryogenic permanent magnet undulator in High Energy Photon Source Testing Facility.The system has two functions:integral field measurement and magnet gap measurement.Integral...A new stretched-wire system is built for a cryogenic permanent magnet undulator in High Energy Photon Source Testing Facility.The system has two functions:integral field measurement and magnet gap measurement.Integral field measurement and gap measurement are important for evaluation and optimization of the magnetic performance of the undulator in cryogenic-vacuum environment.Two high-precision,high-load motion stages are used for accurate positioning.A special fix structure of stretched wire is adopted for vacuum environment.To reduce the deflection of the 3-meter-long wire,constant tension is maintained along the wire.The measurement repeatability of field integral and magnetic gap is the key performance which depends on the stability of wire and suppression of the electric noise.Strategy of improving the measurement accuracy and stability is presented.展开更多
To solve the issue of the contradiction between photovoltaic power generation and plant photosynthesis for sunlight demand, we propose a design method of multi-passband polymer multilayer optical structure. Using poly...To solve the issue of the contradiction between photovoltaic power generation and plant photosynthesis for sunlight demand, we propose a design method of multi-passband polymer multilayer optical structure. Using polycarbonate(PC) and polymethyl methacrylate(PMMA), two polymer materials with different refractive indices, the passband position and passband bandwidth are calculated and adjusted by the transmission matrix method and TFCalc software. A 450 nm,660 nm, and 730 nm three-passband filter was realized by superimposing stacks of different band positions. The feasibility of the photovoltaic agriculture was confirmed by the power generation efficiency and the actual plant growth.展开更多
文摘Background High energy photon source(HEPS)is the fourth-generation light source,which uses a large number of highperformance insertion devices to generate synchrotron radiation.The control system is an important part of the insertion device(ID).Purpose Cryogenic permanent magnet undulator(CPMU)is one kind of IDs that works in liquid nitrogen temperature and ultra-high vacuum environment,and its control system is more difficult and complex than in-air ID.The design of the control system for CPMU will be introduced in detail.Method The sub-systems include high-precision magnetic gap control,safety protection,measurement and compensation of magnetic gap at cryogenic temperature and cryogenic temperature monitoring.Mature,reliable,stable technical schemes are designed to meet the technical specifications of sub-systems.Results The experiment results show that the magnetic gap motion accuracy can be controlled within 0.2–0.3μm under the step size of 1μm.The safety protection system has been tested in turn,and the predetermined protection can be achieved.The average value of magnetic gap cold contraction is 1.512 mm measured by optical micrometer,and the compensation is realized by software.The average temperature of the main magnet structure measured by the temperature sensors is 81.0 K,and the temperature gradient is 0.7 K/m.The temperature monitoring is reliable and stable.Conclusion The CPMU control system which is based on EPICS has been successfully applied to the CPMU prototype,and the test results have met the design specifications.
基金The Grant No.is 11675207.Project name:The Physical and Technical Study of Quasi-eriodic DELTA Undulator working at liquid nitrogen temperature.
文摘Introduction A novel type of pure permanent cryogenic Delta–Knot Undulator was developed at IHEP to supply a high flux of full adjustable polarization synchrotron radiation with low on-axis power density.This prototype was an active attempt and early exploration for future APPLE–Knot undulator,which will be used at high energy photon source(HEPS).Materials and methods There are several challenges to develop a cryogenic delta undulator,such as the complicated structure,the influence of large magnetic force,and the magnetic measurement difficulty due to the very small gap.In this paper,the mechanical design for overcoming these difficulties will be presented in detail.Conclusion A special hall measuring system is developed,and the preliminary results agree with the theoretical results.This undulator prototype will provide valuable experience for angle magnetization technology,intricate magnetic attraction structure design,and magnetic field measurement under closed small space.
文摘A new stretched-wire system is built for a cryogenic permanent magnet undulator in High Energy Photon Source Testing Facility.The system has two functions:integral field measurement and magnet gap measurement.Integral field measurement and gap measurement are important for evaluation and optimization of the magnetic performance of the undulator in cryogenic-vacuum environment.Two high-precision,high-load motion stages are used for accurate positioning.A special fix structure of stretched wire is adopted for vacuum environment.To reduce the deflection of the 3-meter-long wire,constant tension is maintained along the wire.The measurement repeatability of field integral and magnetic gap is the key performance which depends on the stability of wire and suppression of the electric noise.Strategy of improving the measurement accuracy and stability is presented.
基金This work was supported by the CRSRI Open Research Program(No.CKWV2019726/KY)the Fundamental Research Funds for the Central Universities(No.WK529000000)the Fuyang Municipal Government–Fuyang Normal University Horizontal Project(No.SXHZ202011)。
文摘To solve the issue of the contradiction between photovoltaic power generation and plant photosynthesis for sunlight demand, we propose a design method of multi-passband polymer multilayer optical structure. Using polycarbonate(PC) and polymethyl methacrylate(PMMA), two polymer materials with different refractive indices, the passband position and passband bandwidth are calculated and adjusted by the transmission matrix method and TFCalc software. A 450 nm,660 nm, and 730 nm three-passband filter was realized by superimposing stacks of different band positions. The feasibility of the photovoltaic agriculture was confirmed by the power generation efficiency and the actual plant growth.
