Modify RF Cavity of 10 MeV Cyclotron to Improve the Beam Gain by Beam Dynamic Analysis

Abstract

In this study, the central region and beam dynamic of a 10 MeV H− AVF cyclotron called IranCYC10 have been considered. The aim of this cyclotron is to accelerate H− ions up to 10 MeV energy and extract H+ ions to produce PET radioisotopes for medical applications. The cyclotron that is currently in fabrication consists of four sector magnets and two RF cavity parts which operate in 71 MHz frequency. The internal cold-cathode Penning Ion Gauge ion source that was used in this cyclotron, caused the central region design to become very sensitive and complex. In the first step, in order to obtain the optimized beam efficiency at the central region, the beam injection conditions, design of magnet center poles and adjustment of the pullers position have been determined. In contrast to conventional methods which design desired structure of central region based on trial and error, this design is carried out due to consideration of equilibrium orbit. In addition to the beam dynamic analysis in the early turns such as usual works, it is calculated until the extraction of the beam, as the second step. Our new developed code named BDIC (Beam Dynamic of Iran Cyclotron) has been developed for the calculation of the central region and beam dynamics of the cyclotron based on proposed algorithm. This code has been written in C++ program that uses the conventional Runge–Kutta method. The input data of this code including the electric and magnetic field distribution have been designed by OPERA-3D/TOSCA. In order to verify the BDIC code, optimized results of the code have been compared with the results of well-known beam dynamic programs, CYCLONE.