Upgrade and Performance Test of the FPGA-Based Digital LLRF for RAON Accelerator

An ion accelerator, RAON is under construction in Daejeon, Korea, by the Rare Isotope Science Project (RISP) in the Institute of Basic Science (IBS). In this accelerator various ions, such as uranium, proton, carbon, calcium, etc. are planned to be accelerated by using four kinds of superconducting cavities. The four kinds of cavities are the quarter wave resonator (QWR), half wave resonator (HWR), and two kinds of single spoke resonators (SSRs) with different betas. Recently, the upgrade and the performance tests with newly developed field-programmable gate array (FPGA)-based digital low level radio frequency (LLRF) and superconducting cavities were conducted at the superconducting radio frequency (SRF) facility. In this paper, the status and the test result of the RAON LLRF will be described.