Theoretical And Experimental Study Of The CYCIAE-100 Cyclotron Injection System And Central Region

Under the international environment of the fast development on the RIB physics, China Institute of Atomic Energy (CIAE) proposed a BRIF project, which requires a 100MeV proton cyclotron with an average current of 200μA~500μA as a driven accelerator. The high intensity compact cyclotron with an external ion source and an axial injection system will meet a number of technologic challenges. Our dissertation is devoted to investigating problems on the injection system and the central region for the compact cyclotron; a successful solution to these problems will be of great significance both in the technology field and theory field.The thesis works on the beam dynamics study for the compact cyclotron from the external ion source to the procedure of acceleration. A series of investigations on beam transportation have been performed with focus on the layout of the axial injection line, including the main magnet passage and the pulse beam injection; the matching calculations were conducted and the neutralization of H- beam was taken into account. For the spiral inflector, the transfer matrix and fringe electric field were studied. Meanwhile we have attached importance to the beam behavior study in the central region under the joint effects of the magnetic field and electric field on the beam. After the accelerated equilibrium orbit was obtained, we calculated the beam matching in the radial and vertical phase space, and studied radial oscillation, vertical focusing and transverse-longitudinal coupling, etc. Then the injection conditions were determined and proper electrodes were designed to produce the optimum beam qualities. It is put forward in this thesis for the first time the beam matching method from the ion source to the central region of the cyclotron, and a good deal of efforts have been dedicated to the beam dynamics study under multi-physics field for the compact cyclotron, based on which the design of the axial injection system and the central region for CYCIAE-100 were accomplished.A test platform for CYCIAE-100, normally referred to as the CRM cyclotron, was built in CIAE for various experimental verifications for the 100MeV machine. Based on the results of physical design, a specific code was developed to direct the multi-axes numerical milling for various nonstandard elements; then special service tools were manufactured to guarantee the fabricating precision. In order to achieve sufficient information to optimize the beam current, we applied different beam diagnostics devices and obtiained a desirable transmission efficiency of up to 93% for the injection system. In the mean time, the result of RF phase acceptance proves to be in agreement with the physical design.