A two-dimension beam dynamics simulation code base on PIC method

In order to carry out an in-depth study on the negative hydrogen DC beam transport in the axial injection line of CYCIAE-100, a high intensity cyclotron under design at CIAE, the split-operator method is adopted in this paper for macro-particle dynamics simulation. In this method, the Hamiltonian is divided into two parts: external applied field and space-charge field. The former is dealt with single particle tracking and adopts first order approximation; the latter is dealt with PIC method, and FFT technique is used to solve the Poisson equation. Moreover, we developed an object-oriented code of two-dimension macro particle dynamics (CYCPIC2D) using FORTRON 95 language. This code can be applied to the transport line calculation of arbitrarily distributed beam. The simulation result for CYCIAE-100 injection line is presented, and validated by ORBIT and TRACE-3D. It indicates that the space charge effects have significant impact on the injection line, and the results given by three codes are basically accordant with each other. When the beam intensity reaches several ten milliamperes, the two PIC-based codes CYCPIC2D and ORBIT still give consistent results, while the result given by TRACE-3D shows evident difference with the other two.