Design And Key Process Research Of Ultrafast Cooling Pulsed Magnet

With the continuous increase of the working frequency of terahertz gyrotrons,pulsed magnets have gradually become the most ideal choice for terahertz cyclotron magnetic systems.Compared with steady-state magnets,pulsed magnet has the advantages of higher magnetic field strength,lower difficulty and lower cost,which can better meet the needs of highfrequency terahertz magnetic systems.Aiming at the research goals of high magnetic field strength,high cooling rate and high service life,a Polyhelix pulsed magnet with all metal reinforcement and completely free separation was designed.By analyzing the advantages and disadvantages of commonly used fast-cooling magnet structures,Polyhelix structure is used as the design basis.In this paper,high-strength metal martensitic aging steel is used as the reinforcement material.It not only ensures the mechanical properties of the magnet,but also greatly improves the heat dissipation rate of the magnet.In terms of magnet design,the method of COMSOL Multiphysics and MATLAB co-simulation was used to greatly improve the rationality,convenience and efficiency of magnet design.Finally,the initial optimization of the magnet is determined by combining theoretical calculation and practical process.In terms of the mechanical properties of the magnet,a finite element simulation model was built according to the structure and material properties of the magnet.The stress distribution under peak conditions is analyzed to verify the feasibility of the mechanical structure of the magnet.After that,a three-dimensional model was built to analyze the structural stability of the magnet,and the possibility of buckling of the magnet unit layer was determined.In terms of the thermal characteristics of the magnet,the temperature rise distribution characteristics of the magnet under the action of the pulse current are analyzed.The effect of eddy current on heat generation is considered.The thermal characteristics of the magnet is verified.And the natural cooling performance of the magnet is estimated.Then.Combined with theoretical calculation and finite element simulation,the cooling characteristics of the ultra-fast cooling magnet in liquid nitrogen boiling cooling and forced water cooling are analyzed to verify the rapid cooling performance of the magnet.Based on the completion of theoretical research and simulation design of the magnet structure,the key processing technology of the magnet was further explored.A set of magnet processing procedures,including tube making,compounding,screw cutting,and assembly.The screw cutting platform was built to realize the structure of the magnet at a lower cost and a higher level.This will prevent the finished magnet from having large initial defects.Finally,this paper completed the design and key process research of a high-life ultrafast cooling pulsed magnet with a magnetic field of 40 T and a single discharge cooling time of less than 10 s at room temperature.