17–22 May 2026
C.I.D
Europe/Zurich timezone

A novel approach to RF power coupling in Radio-Frequency Quadrupole (RFQ) structures: built-in coaxial double-loop coupling port

TUP7320
19 May 2026, 16:00
2h
C.I.D

C.I.D

Deauville, France
Board: Tuesday baguette: BA16
Poster Presentation MC7.T06: Normal Conducting RF Poster session

Speaker

Sung-Woo Lee (Oak Ridge National Laboratory)

Description

Efficient and reliable RF power couplers in accelerating cavities require precise impedance matching and mechanical stability to ensure optimal beam energy transfer. In radio-frequency quadrupole (RFQ) accelerators, power is commonly delivered using waveguide iris or coaxial loop couplers. Iris couplers can handle high RF power but lack tunability, while coaxial loop couplers offer tuning flexibility but are limited in power handling and thermal performance. We propose a new RFQ power coupling concept utilizing a single input coaxial center-fed double-loop antenna built into a vane in an RFQ structure . The design integrates back-to-back loops into the RFQ vanes, fed by a TEM coaxial transmission line with standard 50-Ω characteristic impedance. The configuration can allow straightforward and easy ceramic window replacement without retuning, and coupling strength is adjusted with protruding tuning rods. Numerical simulations, performed with both a simplified RFQ model and the Spallation Neutron Source RFQ, demonstrate improved RF performance and reduced dipole mode excitation. The results establish the coaxial double-loop coupler as a practical alternative for high-power RFQ coupling applications.

Footnotes

ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. This research was supported by the DOE Office of Science, Basic Energy Science, Scientific User Facilities.
Notice: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, p

Paper status Proceeding files received

Author

Sung-Woo Lee (Oak Ridge National Laboratory)

Co-authors

Charles Peters (Oak Ridge National Laboratory) George Toby (Oak Ridge National Laboratory) Haitao Ren (Oak Ridge National Laboratory) John Moss (Oak Ridge National Laboratory) Sang-Ho Kim (Oak Ridge National Laboratory) Timothy Miner (Oak Ridge National Laboratory) Yoon Kang (Oak Ridge National Laboratory)

Presentation materials