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
Understanding the gluonic structure in nuclei is one of the most important goals in modern nuclear physics,for which J/ψphotoproduction is suggested as a powerful tool to probe the gluon density distribution.The expe...Understanding the gluonic structure in nuclei is one of the most important goals in modern nuclear physics,for which J/ψphotoproduction is suggested as a powerful tool to probe the gluon density distribution.The experimental investigation of the photoproduction process is conventionally studied in ultra-peripheral heavy-ion collisions,and has recently been extended to hadronic collisions.However,theoretical efforts in hadronic heavy-ion collisions are still lacking in the literature.In this paper,we build up a phenomenological framework to calculate the differential momentum transfer spectra for J/ψphotoproduction in hadronic heavy-ion collisions based on a vector meson dominance model.For the first time,we include the effect of internal photon radiation in the calculations,and we find that the results with internal photon radiation could describe the experimental measurements from STAR very well.展开更多
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.
基金Supported by the National Natural Science Foundation of China (12005220, 12175223)MOST (2018YFE0104900)
文摘Understanding the gluonic structure in nuclei is one of the most important goals in modern nuclear physics,for which J/ψphotoproduction is suggested as a powerful tool to probe the gluon density distribution.The experimental investigation of the photoproduction process is conventionally studied in ultra-peripheral heavy-ion collisions,and has recently been extended to hadronic collisions.However,theoretical efforts in hadronic heavy-ion collisions are still lacking in the literature.In this paper,we build up a phenomenological framework to calculate the differential momentum transfer spectra for J/ψphotoproduction in hadronic heavy-ion collisions based on a vector meson dominance model.For the first time,we include the effect of internal photon radiation in the calculations,and we find that the results with internal photon radiation could describe the experimental measurements from STAR very well.
