High Gradient Operation with the CEBAF Upgrade RF Control System

Conference · Wed Aug 16 04:00:00 EDT 2006

OSTI ID:889367

Hovater, J; Davis, G; Dong, Hai; Hofler, Alicia; King, Lawrence; Musson, John; Plawski, Tomasz

The CEBAF Accelerator at Jefferson Lab is presently a 6 GeV five pass electron accelerator consisting of two superconducting linacs joined by independent magnetic transport arcs. Energy will be upgraded to 12 GeV with the addition of 10 new high gradient cryomodules (17+ MV/m). The higher gradients pose significant challenges beyond what the present analog low level RF (LLRF) control systems can handle reliably; therefore, a new LLRF control system is needed. A prototype system has been developed incorporating a large FPGA and using digital down and up conversion to minimize the need for analog components. The new system is more flexible and less susceptible to drifts and component nonlinearities. Because resonance control is critical to reach high gradients quickly, the new cryomodules will include a piezoelectric tuner for each cavity, and the LLRF controls must incorporate both feedback and feed-forward methods to achieve optimal resonance control performance. This paper discusses development of the new RF system, system performance for phase and amplitude stability and resonance control under Lorentz detuning measured during recent tests on a prototype cryomodule.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA
• Sponsoring Organization: USDOE - Office of Energy Research (ER)
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 889367
• Report Number(s): JLAB-ACE-06-529; DOE/ER/40150-4006
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATORS
AMPLITUDES
CEBAF ACCELERATOR
CONTROL SYSTEMS
ELECTRONS
FEEDBACK
LINEAR ACCELERATORS
PERFORMANCE
RESONANCE
RF SYSTEMS
STABILITY
TRANSPORT