Research On The Technology Of The Inner Negative Hydrogen Ion Sources Of CYCHU-10Cyclotron

Low-energy cyclotron is widely used in biology, medicine, basic research of nuclearphysics and other fields. Ion source is a key component of Cyclotron, which providesreliable and stable ion beam for Cyclotron. In recent years, with the rapid development ofthe positron emission tomography(PET)technology, small medical cyclotron with energy ofabout10~20MeV,which produces the short-lived radioisotopes is widely developed andapplied. The inner negative hydrogen Penning ion source with cold cathode is usually usedbecause of the compact structure and the simple operation. In this study, the ion source isplaced in the center of the cyclotron, the ion beam provided is up to35μA and the ionenergy extracted from the accelerator is about10MeV.The main work of the research about the negative hydrogen Penning ion source is asfollows: Chapter1describes the purpose and significance of the research about ion sourceand the domestic and foreign study;Chapter2introduces the basic concepts of ion sourceplasma and discharge principle, then studies the effects of the gas pressure and dischargevoltage on the discharge, simulates the motion of electron in the dischage chamber with andwithout magnetic field and summarizes that magnetic field can increase the path of electronin the chamber, and enhance the collision ionization betweent electron and gas molecules;Chapter3focuses on the theory and methods of the beam extraction. According to theactual requirements of the ion source extraction system, the beam extraction simulation isapplied by using Ansys and Matlab, and the trajectories of charged particles with andwithout magnetic field are got. The summary is that the magnetic field can separateelectrons from negative hydrogen ions to increase the purity of negative hydrogen beam,can make electrons gather in plasma sheath to change the shape and position of emissionsurface,and have an effect on beam extraction, so the suitable magnetic field is studied toget better beam extraction; Finally, chapter4summarizes the research and the deficienciesof work.