Dealing with Multipacting in Fundamental Power Couplers for SRF Cavities

Conference · Sat Mar 19 04:00:00 EST 2005

OSTI ID:876417

Stirbet, Mircea

Multipacting events are well known and bothersome discharge phenomena specific to vacuum and RF exposed surfaces. Left uncontrolled, these events could affect normal machine operation, limiting performance or inducing irreversible damage of critical components such as ceramic windows. Numerical simulations have been developed and their predictions fit fairly well with real multipacting events in coaxial lines or waveguide-type fundamental power couplers. Controlling multipacting must be considered from the design stage, as well as during manufacture of subassemblies or preparation of the coupler for cavity assembly. All fundamental power couplers must be conditioned using a high power RF source, and during this process, restricting multipacting by adequate instrumentation should be considered. After RF conditioning, during beam acceleration, control of multipacting is achieved with field perturbation methods. This paper summarizes our experience in dealing with multipacting in CW or pulsed fundamental power couplers (LEP, LHC, SNS and RIA) for SRF cavities. The SNS fundamental power coupler is used as an example for controlling multipacting during high power RF conditioning.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA
• Sponsoring Organization: USDOE - Office of Energy Research (ER)
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 876417
• Report Number(s): JLAB-ACC-05-312; DOE/ER/40150-3759
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATION
COMPUTERIZED SIMULATION
COUPLING
DESIGN
NEUTRON SOURCES
PERFORMANCE
POWER SYSTEMS
RF SYSTEMS
SPALLATION
SUPERCONDUCTING CAVITY RESONATORS