Design Study Of A Dipole Magnet Applied To Proton Therapy Beamline

In recent years,proton therapy technology has been developing very fast.The proton therapy facility is an extremely complex system.The dipole magnet is mainly used to deflect and focus the beam on the beam transport line of the proton therapy facility.Based on the optics calculation of HUST-PTF,the 60°parallel-edge dipole magnet should be designed and optimized,especially to ensure the homogeneity of the magnetic field for both high and low fields corresponding to a wide range of beam energy.And the physical size of the magnet is optimized by magnet pole optimization to reduce the weight and cost of the magnet,while the quality of the magnetic field within the good field region is guaranteed at the same time.In the thesis,based on the requirements of HUST-PTF beam line,the detailed physical design optimization and preliminary engineering design for the 60° parallel-edge dipole magnet are presented.When the width of the pole is limited,it is difficult to meet all specifications of both high and low fields for the dipole.In the optimization process of the two-dimensional cross section,two schemes are compared:central hole and trapezoidal shimming along with arc transition.After comprehensive consideration,the second design scheme was adopted.Rogowski curve and harmonic shimming for the three-dimensional model are used to reduce the quadrupole and sextupole components of the magnetic field.Finally,in the range of high and low magnetic field?0.80-1.62 T?,the magnetic field error in cross-section is reduced within±5?10^-4 in good field region,the integral field error is controlled within±1?10^-3 and the harmonic field error is controlled within±5?10^-4,which meets the design specifications.At the same time,a preliminary engineering design is also carried out,including the water cooling design for the coils.Finally,the magnet design can meet the requirements of high central magnetic field,reasonable electrical/water cooling parameters and compactness of the structure.It is suitable for the application in the beam line system for proton therapy facility.In order to improve the central magnetic field and minimize the size of the magnet,the pre-study,preliminary design and calculation of superconducting CCT ?Canted-Cosine-Theta?dipole magnets are carried out.The coil modeling is one of the key techniques during the design process.Based on the electromagnetic principle and referring other papers,the path formula of straight CCT superconducting coils is given.This thesis deduces the coil path for bending CCT magnet based on the mathematical principle,and gives a simple and intuitive path formula to provide design reference for the future superconducting gantry scheme.