The vibrating wire alignment technique is a method which, by measuring the spatial distribution of a magnetic field, can achieve very high alignment accuracy. The vibrating wire alignment technique can be applied to f...The vibrating wire alignment technique is a method which, by measuring the spatial distribution of a magnetic field, can achieve very high alignment accuracy. The vibrating wire alignment technique can be applied to fiducializing magnets and the alignment of accelerator straight section components, and it is a necessary supplement to conventional alignment methods. This article gives a systematic summary of the vibrating wire alignment technique, including vibrating wire model analysis, system frequency calculation, wire sag calculation, and the relation between wire amplitude and magnetic induction intensity. On the basis of this analysis, this article outlines two existing alignment methods, one based on magnetic field measurement and the other on amplitude and phase measurements. Finally, some basic experimental issues are discussed.展开更多
The alignment tolerance of multipoles on a girder is better than ±30 μm in the storage ring of the High Energy Photon Source （HEPS） which will be the next project at IHEP （Institute of High Energy Physics）. ...The alignment tolerance of multipoles on a girder is better than ±30 μm in the storage ring of the High Energy Photon Source （HEPS） which will be the next project at IHEP （Institute of High Energy Physics）. It is difficult to meet the precision when only using the traditional optical survey method. In order to achieve this goal, a vibrating wire alignment technique with high precision and sensitivity is considered to be used in this project. This paper presents some preliminary research works about theory, scheme design and achievements.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
Purpose The magnet sorting is a standard step in the undulator fabrication procedure.The shortest undulators period used in the High Energy Photon Source(HEPS)is only 12 mm.To the short period undulator,the sorting ma...Purpose The magnet sorting is a standard step in the undulator fabrication procedure.The shortest undulators period used in the High Energy Photon Source(HEPS)is only 12 mm.To the short period undulator,the sorting may be more important than the long-period undulator.Normally,the Helmholtz measurement is used as the input for the work.It is the averaged orthogonal magnetization of each block.In order to investigate whether the Helmholtz coil measurement is enough for the sorting,a careful study has been made.Method Firstly,a magnetic camera was used to scan the 3D surface field of a magnet.Afterward,its field integral ismeasured by the stretched wire.In the measurement,the magnetwas placed at different statuses.The results were checked to seewhether they are consistent with expected features supposing a homogeneous magnetized block.Finally,the results measured by the Helmholtz coil and the stretched wire were compared.Results The surface field scan demonstrates that the field over a magnet block is inhomogeneous.Moreover,the field integral measurement by the stretched wire also shows big difference when the different magnet sides toward thewire.The comparison between the stretched wire and the Helmholtz coil measurement shows no correlation.Conclusion The study presented in this paper reveals that the homogeneity of the magnetization is imperfect.Therefore,the Helmholtz coil data are insufficient to the short-period undulators sorting.展开更多
A wire rope defects detection method based on permanent magnet excitation is proposed.A detection system,mainly composed of permanent magnet excitation,distance detection,multi-sensor magnetic flux leakage signal acqu...A wire rope defects detection method based on permanent magnet excitation is proposed.A detection system,mainly composed of permanent magnet excitation,distance detection,multi-sensor magnetic flux leakage signal acquisition and data analysis device,is set up.According to the different characteristics of the multi-sensor magnetic flux leakage signal,the localized fault(LF)and loss of metallic cross-sectional area(LMA)signal is separated,and then the two defects can be detected.The experiments show that the method can effectively detect the two defects when they appear simultaneously on the wire rope.展开更多
文摘The vibrating wire alignment technique is a method which, by measuring the spatial distribution of a magnetic field, can achieve very high alignment accuracy. The vibrating wire alignment technique can be applied to fiducializing magnets and the alignment of accelerator straight section components, and it is a necessary supplement to conventional alignment methods. This article gives a systematic summary of the vibrating wire alignment technique, including vibrating wire model analysis, system frequency calculation, wire sag calculation, and the relation between wire amplitude and magnetic induction intensity. On the basis of this analysis, this article outlines two existing alignment methods, one based on magnetic field measurement and the other on amplitude and phase measurements. Finally, some basic experimental issues are discussed.
文摘The alignment tolerance of multipoles on a girder is better than ±30 μm in the storage ring of the High Energy Photon Source （HEPS） which will be the next project at IHEP （Institute of High Energy Physics）. It is difficult to meet the precision when only using the traditional optical survey method. In order to achieve this goal, a vibrating wire alignment technique with high precision and sensitivity is considered to be used in this project. This paper presents some preliminary research works about theory, scheme design and achievements.
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.
文摘Purpose The magnet sorting is a standard step in the undulator fabrication procedure.The shortest undulators period used in the High Energy Photon Source(HEPS)is only 12 mm.To the short period undulator,the sorting may be more important than the long-period undulator.Normally,the Helmholtz measurement is used as the input for the work.It is the averaged orthogonal magnetization of each block.In order to investigate whether the Helmholtz coil measurement is enough for the sorting,a careful study has been made.Method Firstly,a magnetic camera was used to scan the 3D surface field of a magnet.Afterward,its field integral ismeasured by the stretched wire.In the measurement,the magnetwas placed at different statuses.The results were checked to seewhether they are consistent with expected features supposing a homogeneous magnetized block.Finally,the results measured by the Helmholtz coil and the stretched wire were compared.Results The surface field scan demonstrates that the field over a magnet block is inhomogeneous.Moreover,the field integral measurement by the stretched wire also shows big difference when the different magnet sides toward thewire.The comparison between the stretched wire and the Helmholtz coil measurement shows no correlation.Conclusion The study presented in this paper reveals that the homogeneity of the magnetization is imperfect.Therefore,the Helmholtz coil data are insufficient to the short-period undulators sorting.
文摘A wire rope defects detection method based on permanent magnet excitation is proposed.A detection system,mainly composed of permanent magnet excitation,distance detection,multi-sensor magnetic flux leakage signal acquisition and data analysis device,is set up.According to the different characteristics of the multi-sensor magnetic flux leakage signal,the localized fault(LF)and loss of metallic cross-sectional area(LMA)signal is separated,and then the two defects can be detected.The experiments show that the method can effectively detect the two defects when they appear simultaneously on the wire rope.
