SRF2011 - List of Authors (Glennon, P.)

Paper	Title	Page
TUPO004	Development and Testing of Prototype Fundamental Power Couplers for FRIB Half Wave Resonators	353
	J. Popielarski, P. Glennon, M. Hodek, J. Wlodarczak FRIB, East Lansing, Michigan, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. The driver linac for the Facility for Rare Isotope Beams (FRIB) requires superconducting Half Wave Resonators to accelerate ions to 200 MeV per nucleon. The Fundamental Power Coupler (FPC) is designed to deliver up to 14 kW of RF power at 322 MHz to the resonator and the beam in CW, and to increase the resonator’s control bandwidth for stable operation. With the resonator over-coupled, the mismatch creates a standing wave in the FPC and transmission line downstream of the circulator. The FPC includes an alumina vacuum barrier to allow the resonator to be under ultra-high vacuum. The FPC also serves as a thermal break between the room-temperature transmission line and the resonator at 2 K, with thermal intercepts designed to minimize the heat load to the cryoplant. The FPC design allows for some variation in the coupling, in case a larger bandwidth is needed to mitigate microphonic disturbances. The RF and mechanical design of the coupler and conditioning stand will be reviewed, and the results of high power RF conditioning and testing will be presented.

Paper

Title

Page

Development and Testing of Prototype Fundamental Power Couplers for FRIB Half Wave Resonators

353

J. Popielarski, P. Glennon, M. Hodek, J. Wlodarczak
FRIB, East Lansing, Michigan, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The driver linac for the Facility for Rare Isotope Beams (FRIB) requires superconducting Half Wave Resonators to accelerate ions to 200 MeV per nucleon. The Fundamental Power Coupler (FPC) is designed to deliver up to 14 kW of RF power at 322 MHz to the resonator and the beam in CW, and to increase the resonator’s control bandwidth for stable operation. With the resonator over-coupled, the mismatch creates a standing wave in the FPC and transmission line downstream of the circulator. The FPC includes an alumina vacuum barrier to allow the resonator to be under ultra-high vacuum. The FPC also serves as a thermal break between the room-temperature transmission line and the resonator at 2 K, with thermal intercepts designed to minimize the heat load to the cryoplant. The FPC design allows for some variation in the coupling, in case a larger bandwidth is needed to mitigate microphonic disturbances. The RF and mechanical design of the coupler and conditioning stand will be reviewed, and the results of high power RF conditioning and testing will be presented.