A Study on the Improvement of the Superconducting Magnet System for the 28 GHz SC-ECRIS at KBSI

The Busan Ion Beam Accelerator (BIBA) is a compact linear accelerator facility utilizing the 28 GHz Superconducting Electron Cyclotron Resonance Ion Source (SC-ECRIS) at the Korea Basic Science Institute (KBSI). The primary objective of the BIBA is to produce fast neutrons tailored for high-resolution radiography technology and application. A recent development of a new ion implantation system employs the multi-charged ion beams, produced by 28 GHz SC-ECRIS. The 28 GHz SC-ECRIS generates a high magnetic field for strong plasma confinement. For the reliable operation of superconducting magnets, it is essential to analyze their electromagnetic characteristics to minimize the forces inducing coil motion and strain during excitation. In this paper, we have employed the inner yoke of the superconducting magnets to enhance the operational stability. The effect of the inner yoke has been analyzed by both a three-dimensional static finite element method simulation and magnetic field measurements in the plasma chamber. The research presents an analysis of the magnetic field and the electromagnetic force of the superconducting magnets under various conditions of the inner yokes. As a result, the magnetic field measurements were found to be in good agreement with the simulated results.