JLab, Newport News, Virginia, USA
The Continuous Electron Beam Accelerator Facility (CEBAF) 12 GeV upgrade reached its design energy in December of 2015. Since then CEBAF has been delivering 12 GeV beam to experimental Hall D and 11 GeV to experimental halls A and B in support of Nuclear physics. To meet this energy goal, ten new 100 MV cryomodules (80 cavities) and RF systems were installed in 2013. The superconducting RF cavities are designed to operate CW at a average accelerating gradient of 19.2 MV/m. To support the higher gradients and higher QL (3.2×107) operations, the RF system uses 13 kW klystrons and digital LLRF to power and control each cavity. This paper reports on the C100 operation and optimization improvements of the RF system and cryomodules.
JLab, Newport News, Virginia, USA
The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of four new 748.5 MHz normal conducting deflecting cavities in the 5th pass extraction region. The RF system employs two digital LLRF systems controlling four normal conducting cavities in a vector sum setting. Cavity tune information of the individual cavities is obtained using a multiplexing scheme of the forward and reflected RF signals. Water skids equipped with heaters and valves are used to control resonance. A new FPGA-based hardware and EPICS-based predictive control algorithm has been developed to support reliable operation of the beam extraction process. This paper presents the architecture design of the existing hardware and software as well as a plan to develop a model predictive control system.