Study On Bunched Ion Beam Cooling And EicC Beam Cooling Simulation

The study of the internal structure of nucleons is an important frontier of current theoretical and experimental research.Electron-ion colliders are an ideal tool for ex-ploring the structure of nucleons.Brookhaven National Laboratory（BNL）is currently building the EIC,and CERN is planning to build the Large Hadron Electron Collider LHe C on top of the LHC.In order to increase our country’s international competitive-ness in the field of high-energy nuclear physics,the Polarized Electron-Ion Collider in China（EicC）project was proposed on the basis of the high-intensity heavy ion ac-celerator（HIAF）project,which is already under construction by Institute of Modern Physics,Chinese Academy of Sciences.EicC will provide both polarized electron and proton beams with a luminosity of 2×10³³cm^–2s^–1and a center mass energy of 15～20Ge V.Luminosity is the most important parameter of EicC,and the effective cooling of high-current,high-energy ion beams is the key for EicC to achieve the luminosity goal.According to the characteristics of large initial emittance,high energy and high intensity of ion beam parameters in EicC,this thesis proposes a two-staged beam cooling scheme.A traditional DC electron cooler is installed in the booster ring（BRing）to reduce the ion beam emittance.In the collider ring（p Ring）,a high-energy bunched beam cooling system based on an energy recovery linac（ERL）is used to suppress the ion beam emittance growth due to intra-beam scattering effects during the collision process.DC electron cooling has become more mature after years of development.Although bunched electron beam cooling has been experimentally verified,further studies are needed on the cooling properties and the influencing factors.In this thesis,a multi-particle tracking program is developed to simulate the bunched beam cooling process,and then experimental studies on bunched beam cooling and modulated electron beam cooling are carried out with the help of a low-energy cooling device in CSRm.The space charge effect of electron beam on ion beam is explored based on the experimental results,and the reliability of the program is verified by experimental results.Finally,the two-stage cooling process of EicC is simulated,and by optimizing the electron beam size,temperature,magnetic field and lattice function in the cooling section,the proton beam is effectively cooled to meet the requirements of collision luminosity of EicC.