SKKU, Suwon
PAL, Pohang, Kyungbuk
The low level RF (LLRF) control system for PLS is being upgraded to improve the performance of the system. The LLRF control system under development consists of FPGA, and high speed ADC and DAC as well as analog front-end devices which process the signal from cavity and to RF high power system. In addition, it utilizes digital signal processing technology based on FPGA. In order to optimize the accelerating electric field in the cavity, it is required to maintain field stability less than ±1% in amplitude and 1° in phase. And the resonance condition of the cavity should be monitored and controlled. The various digital signal processing theories such as digital filters, Cordic, PI control enable to meet these requirements and to control the feedback signal less than a microsecond. The LLRF control system is also equipped with the Ethernet by the cPCI. The preliminary design study on the LLRF control system for PLS superconducting cavity will be described in this paper.
PAL, Pohang, Kyungbuk
Since its completion in 1993, the PLS (Pohang Light Source) linear accelerator has been operated as the full energy injector to the PLS storage ring - a 2.5-GeV 3rd generation light source in Korea. After successful services for more than 15 years to the Korean synchrotron radiation users' community, the PLS is now being upgraded to meet ever-increasing user demands for brighter lights. The PLS-II, the major upgrade program to the PLS, is to increase the beam energy to 3 GeV, changing the storage ring lattice to accommodate large number of insertion devices with lower emittance, and to have the top-up injection as the default operating mode. In order to achieve high injection efficiency (> 80%), beam qualities including the energy spread, pulse length, and jitters in bunch arrival times to the storage ring rf bucket have to be reduced. After successful upgrade of the PLS linac one could further exploit its potential by, for example, implementing high-brightness electron source, which would open up new possibilities with the facility
