Study on Proton Beam Extraction System of 13 MeV Cyclotron

A study of the proton beam extraction system on the DECY-13 cyclotron has been carried out. In the development of the cyclotron, the study of the extraction system is very important to find out the exact location of the foil stripper and the characteristics of the beam so that the production of radioisotopes by cyclotrons can be optimal. This study aims to determine the position of the foil stripper and the characteristics of the beam. The study was carried out by simulating the beam trajectory and beam dynamics. The beam's characteristics include beam stability, energy gain per turn, vertical movement, and turn separation. Simulations were carried out using the CYCLONE simulation program. The results show that the stripper foil can be placed at radius r ≈ 41.5 cm with phase width of 120°. Minimum turn number to achieve 13 MeV is 83 turn, and energy gain per turn is 73 − 157 keV. The beam experiences radial resonance (v5 = 1) at the beginning of the acceleration, which causes a phase shift of about ±2°. The maximum vertical movement of the beam is still within the range of the dee gap (±1 cm) which is about ±0.5 cm from the median plane.