In this paper, we report a ferromagnetic resonance study on the permalloy film of submicron sized rectangular arrays prepared by electron beam lithography and the theoretical simulation to the non uniform demagnetiz...In this paper, we report a ferromagnetic resonance study on the permalloy film of submicron sized rectangular arrays prepared by electron beam lithography and the theoretical simulation to the non uniform demagnetizing effect and ferromagnetic resonance data. By theoretical simulation, the magnetization, gyromagnetic ratio and g value of the sample are determined. The theoretical curves of the dependence of the resonance field on the field orientation φ H fit well with the experimental data. When the steady magnetic field is applied near the film normal, a series of additional regular peaks (up to eight ) appeared in the FMR spectrum on the low field side of the main FMR peak. The resonance field of these side peaks decreases linearly with the peak number. The possible physical mechanism of these multiple peaks was discussed.展开更多
The Central Region Model(CRM)is a compact H^- cyclotron.Because of the intrinsic asymmetry of the magnet,its machining and assembly are very complicated.To guarantee the magnet field distribution,it is necessary to me...The Central Region Model(CRM)is a compact H^- cyclotron.Because of the intrinsic asymmetry of the magnet,its machining and assembly are very complicated.To guarantee the magnet field distribution,it is necessary to measure and shim the magnetic field.This paper presents a study on the design and use of the mapping system based on the Hall Effect and the re-machining of shimming bars after analyzing the magnetic field measurement data to achieve the isochronous field and good vertical focusing frequency.The method to effectively reduce the amplitude of the 1st harmonic by shimming bars ls also introduced.展开更多
A 100MeV compact high intensity H-cyclotron is under design and construction at CIAE which will provide a 75MeV—100MeV,200μA proton beam.The main magnet of this cyclotron adopts an integrally compact structure with ...A 100MeV compact high intensity H-cyclotron is under design and construction at CIAE which will provide a 75MeV—100MeV,200μA proton beam.The main magnet of this cyclotron adopts an integrally compact structure with a fixed field and four sectors,while the hill gap is constantly changeable.This paper reviews the design features of the magnet,numerical simulation results,the inner defects of the magnet including the carbon content segregation and shrinkage porosity,factors related to mechanical design including the tolerance and deformation.The latest progress will also be reported in this paper.展开更多
文摘In this paper, we report a ferromagnetic resonance study on the permalloy film of submicron sized rectangular arrays prepared by electron beam lithography and the theoretical simulation to the non uniform demagnetizing effect and ferromagnetic resonance data. By theoretical simulation, the magnetization, gyromagnetic ratio and g value of the sample are determined. The theoretical curves of the dependence of the resonance field on the field orientation φ H fit well with the experimental data. When the steady magnetic field is applied near the film normal, a series of additional regular peaks (up to eight ) appeared in the FMR spectrum on the low field side of the main FMR peak. The resonance field of these side peaks decreases linearly with the peak number. The possible physical mechanism of these multiple peaks was discussed.
文摘The Central Region Model(CRM)is a compact H^- cyclotron.Because of the intrinsic asymmetry of the magnet,its machining and assembly are very complicated.To guarantee the magnet field distribution,it is necessary to measure and shim the magnetic field.This paper presents a study on the design and use of the mapping system based on the Hall Effect and the re-machining of shimming bars after analyzing the magnetic field measurement data to achieve the isochronous field and good vertical focusing frequency.The method to effectively reduce the amplitude of the 1st harmonic by shimming bars ls also introduced.
文摘A 100MeV compact high intensity H-cyclotron is under design and construction at CIAE which will provide a 75MeV—100MeV,200μA proton beam.The main magnet of this cyclotron adopts an integrally compact structure with a fixed field and four sectors,while the hill gap is constantly changeable.This paper reviews the design features of the magnet,numerical simulation results,the inner defects of the magnet including the carbon content segregation and shrinkage porosity,factors related to mechanical design including the tolerance and deformation.The latest progress will also be reported in this paper.
