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Title: High Gradient Operation with the CEBAF Upgrade RF Control System

Conference ·
OSTI ID:889367

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 (TJNAF), Newport News, VA (United States)
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; TRN: US0604437
Resource Relation:
Conference: LINAC 2006, 21-25 Aug 2006, Knoxville, Tennessee
Country of Publication:
United States
Language:
English