Optimization And Simulation Of Two Planes Painting Injection Scheme For HIAF-BRing

Particle accelerators are important nuclear physics experiment platform.Since the particle accelerator was invented in the 1930 of the 20 th century,peoples kept improving the performance of accelerators.As the new generation of heavy-ion accelerator in China,High Intensity Heavy-ion Accelerator Facility?HIAF?is under design and construction by Institute of Modern Physics,Chinese Academy of Sciences,to meet the need for high intensity heavy-ion beam.HIAF will provide the highest intensity intermediate and low energy heavy-ion pulse among the relative facilities in the world.The accelerator chain of HIAF includes Super-conducting Electron Cyclotron Resonance?SECR?ion source,Ion Linac?i Linac?,Booster Ring?BRing?,Spectrometer Ring?SRing?.BRing is the main ring of HIAF and its design intensity is 1×10¹¹ppp(for ²³⁸U³⁴⁺).To inject enough particles and reduce the risk of beam loss due to resonance,two planes painting injection scheme is applied for BRing.Two planes painting injection method is firstly proposed by C.R.Prior in the 1990 of 20 th century.This method paints injected beams into the acceptance of the ring using an inclined electrostatic septum and a group of horizontal and vertical bump magnets.It can injected more particles into the ring than typical single plane painting method and achieve a uniform particles distribution.The performance of injection system is sensitive to the value of injection parameters,so we optimized the injection parameters to achieve a higher injection performance in this thesis.A optimization code is developed base on MATLAB to optimize the injection parameters.To reduce the amount of computation,some approximate methods and genetic algorithm are applied in this code.The injection process with optimal injection parameters is simulated using ORBIT code to test the correctness of our optimization code.As a particle tracking code,ORBIT considers the space charge effect using PIC method.The simulation results shows that 113 turns are injected into the ring,110.3 turns are retained,and it efficiency is 97.7%.The accumulated beams are distributed uniformly and therefore they have a small tune shift of-0.02.It shows that the results of optimization is correct and injection scheme with optimal injection can meet the injection gain demand of BRing.The influence of the growth of injection emittance,deviation of direction of injected beam,angle error of electrostatic septum,deviation of machine working point,delay of power supply of bump magnets are analyzed.The results shows that the injection efficiency of injection process with these errors is kept more than 95% and therefore the demand of BRing can be met.