Study of improvement of a central region and an extraction system of the RCNP AVF cyclotron

High quality and high intensity beam of AVF cyclotron at RCNP is used for both nuclear physics and various applied research. It is needed to increase beam intensity for the needs of nuclear medicine. An improvement of injection line, inflector, and central region of cyclotron is needed to increase the intensity of accelerated beam of cyclotron, while extraction system, which limits extraction beam current and causes radio-activation must be improved. Simulation study utilizing SNOP code is performed for high efficiency beam in the cyclotron with space charge effect. The structure of extraction system was determined to increase the efficiency of extraction. (author)