The Emission,transmission And Collection Of Electron Beams In HIAF Sring Electron Cooling

Electron cooling can effectively reduce the beam energy spread and emittance in the ion storage ring.In the inner target experiment,electron cooling can suppress the ion beam scattering,and can compensate for the energy loss of the ion beam in collision process.For these reasons,electron cooling is widely used in the ion storage ring.Cooling the ion beam fastly is the most fundamental goal of electron cooling.To achieve this goal,an electronic cooling should meet the following requirements: First,the electron beam should be emitted with low temperature and the temperature should not increase when the electron be transmitted to the cooling section;Secondly,to decrease the efficient temperature of the electron beam the force line of the guide field should straight enough in the cooling section.Third,the electron beam has to be collected efficiently to improve the stability of the high voltage power supply system.Based on these basic principles of electron cooling,the design point of HIAF-SRing electron cooling are described in this paper.The electron beam temperature evolution in the electron gun region is studied by numerical simulation and analytical method,the electron beam temperature depend on the strength of the guide magnetic field is researched.An electron gun with variable beam distribution is designed for HIAF-SRing.The adiabatic expansion process of the electron beam is studied,and the magnetic field design of the adiabatic expansion and in acceleration region are proposed.The amount of the temperature increasing of electron beam during acceleration process is studied,and the method to suppress the temperature increasing is proposed.The beam motion in toroid is researched by numerical simulation and analytical methods.The mechanism of electron beam temperature increase in toroid is found out,and a design is proposed to avoid the beam temperature increase in the toroid.In this paper,the numerical simulation and analytical calculation methods are used to study the increase of electron beam temperature caused by magnetic field error.A method base on a short solenoid is proposed to suppress the temperature increasing caused by magnetic field error.The beam motion in the collector is researched.To simulate the generation of secondary electrons in the collector,and to optimize the design of the collector,a code based on Monte Carlo simulation is developed.The simulation results for the collector of the HIAF electron cooler are summarized in this paper.A test set-up was built to evaluate the gun and collector design proposed for HIAF.The experiment results for the gun and the collector are summarized in this paper.The simulated results is confirmed by the experiments.