Simulation of the effect of input Dee voltage and magnetic field on ion beam trajectories in central region of cyclotron DECY 13

Abstract

Center for Accelerator Science and Technology (CAST) BATAN Yogyakarta has a project for constructing and developing a cyclotron facility for radioisotope production named DECY-13. In the DECY-13 cyclotron, the amount of power supplied is expected to be a voltage 40 kV at the RF Dee. In the RF system, there are reflected power and power loss. All incoming power to RF systems is non-transmissible. The achieved voltage will affect the ion beam trajectory that occurs. In the development of a cyclotron, it is important to know how the beam trajectories inside the cyclotron chamber was occur. Beam trajectories simulation is needed to estimate the beam movement inside the cyclotron chamber. The purpose of this research is to know the minimum magnetic and Dee voltage for the beam passing through the puller and a beam guide. The beam trajectories code was written in Scilab 5.4.1 using Runge-Kutta 4 method. The distance between the head of the ion source and the puller was set to 4 mm. The input for trajectories simulation is the variation of the input distributions of the electric and magnetic fields on the cyclotron. The beam trajectory, especially in the central region was analyzed. The simulation results show that the minimum voltage required for the beam to pass-through the puller and experience acceleration is 10 kV with a magnetic field value of 0.86 T. Simulation results can be used for the experimental reference of the low energy beam testing at cyclotron DECY-13.