SRF2015 - List of Authors (Rathke, J.)

Paper	Title	Page
THPB088	20 kW CW Power Couplers for the APS-U Harmonic Cavity	1346
	M.P. Kelly, A. Barcikowski, Z.A. Conway, D. Horan, M. Kedzie, S.H. Kim, P.N. Ostroumov ANL, Argonne, Illinois, USA S.V. Kutsaev RadiaBeam, Santa Monica, California, USA J. Rathke AES, Medford, New York, USA
	Funding: This work supported by the U.S. DOE, Office of Nuclear Physics, Contract No. DE-AC02-06CH11357. This research used resources of ANL’s ATLAS facility, which is a DOE Office of Science User Facility. A pair of 20 kW CW adjustable RF power couplers optimized for 1.4 GHz have been designed and are being built as part of the APS-U bunch lengthening system. The system uses one superconducting RF cavity to be installed into the APS Upgrade electron storage ring and will provide a tremendous practical benefit to the majority of users by increasing the beam lifetime by 2-3 times. The 80 mm diameter, 50 Ω coaxial couplers include 4 cm (~20 dB) of adjustability. This allows optimization of bunch lengthening for a range of storage ring beam currents and fill patterns while, simultaneously, maintaining the required 0.84 MV harmonic cavity voltage. To provide bunch lengthening, the cavity/coupler system must extract RF power (up to 32 kW) from the beam. Each coupler will transmit roughly half of the total extracted power to external water-cooled loads. The design extends upon on a well-tested ANL two RF window concept, using a pair of simple rugged 80 mm diameter alumina disks. A new feature is the ‘hourglass-shaped’ inner conductor chosen to maximize transmission at 1.4 GHz. Results of electromagnetic and thermal simulations, as well as, prototyping and initial RF testing are presented.
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THPB105	Demonstration of Coaxial Coupling Scheme at 26 MV/m for 1.3 GHz Tesla-Type SRF Cavities	1397
	Y. Xie, A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA T.N. Khabiboulline, A. Lunin, V. Poloubotko, A.M. Rowe, N. Solyak, V.P. Yakovlev Fermilab, Batavia, Illinois, USA J. Rathke AES, Medford, New York, USA
	Superconducting ILC-type cavities have an rf input coupler that is welded on. A detachable input coupler will reduce conditioning time (can be conditioned separately), reduce cost and improve reliability. The problem with placing an extra flange in the superconducting cavity is about creating a possible quench spot at the seal place. Euclid Techlabs LLC has developed a coaxial coupler which has an on the surface with zero magnetic field (hence zero surface current). By placing a flange in that area we are able to avoid disturbing surface currents that typically lead to a quench. The coupler is optimized to preserve the axial symmetry of the cavity and rf field. The surface treatments and rf test of the proto- type coupler with a 1.3 GHz ILC-type single-cell cavity at Fermilab will be reported and discussed.
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

Paper

Title

Page

20 kW CW Power Couplers for the APS-U Harmonic Cavity

1346

M.P. Kelly, A. Barcikowski, Z.A. Conway, D. Horan, M. Kedzie, S.H. Kim, P.N. Ostroumov
ANL, Argonne, Illinois, USA
S.V. Kutsaev
RadiaBeam, Santa Monica, California, USA
J. Rathke
AES, Medford, New York, USA

Funding: This work supported by the U.S. DOE, Office of Nuclear Physics, Contract No. DE-AC02-06CH11357. This research used resources of ANL’s ATLAS facility, which is a DOE Office of Science User Facility.
A pair of 20 kW CW adjustable RF power couplers optimized for 1.4 GHz have been designed and are being built as part of the APS-U bunch lengthening system. The system uses one superconducting RF cavity to be installed into the APS Upgrade electron storage ring and will provide a tremendous practical benefit to the majority of users by increasing the beam lifetime by 2-3 times. The 80 mm diameter, 50 Ω coaxial couplers include 4 cm (~20 dB) of adjustability. This allows optimization of bunch lengthening for a range of storage ring beam currents and fill patterns while, simultaneously, maintaining the required 0.84 MV harmonic cavity voltage. To provide bunch lengthening, the cavity/coupler system must extract RF power (up to 32 kW) from the beam. Each coupler will transmit roughly half of the total extracted power to external water-cooled loads. The design extends upon on a well-tested ANL two RF window concept, using a pair of simple rugged 80 mm diameter alumina disks. A new feature is the ‘hourglass-shaped’ inner conductor chosen to maximize transmission at 1.4 GHz. Results of electromagnetic and thermal simulations, as well as, prototyping and initial RF testing are presented.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THPB105

Demonstration of Coaxial Coupling Scheme at 26 MV/m for 1.3 GHz Tesla-Type SRF Cavities

1397

Y. Xie, A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA
T.N. Khabiboulline, A. Lunin, V. Poloubotko, A.M. Rowe, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA
J. Rathke
AES, Medford, New York, USA

Superconducting ILC-type cavities have an rf input coupler that is welded on. A detachable input coupler will reduce conditioning time (can be conditioned separately), reduce cost and improve reliability. The problem with placing an extra flange in the superconducting cavity is about creating a possible quench spot at the seal place. Euclid Techlabs LLC has developed a coaxial coupler which has an on the surface with zero magnetic field (hence zero surface current). By placing a flange in that area we are able to avoid disturbing surface currents that typically lead to a quench. The coupler is optimized to preserve the axial symmetry of the cavity and rf field. The surface treatments and rf test of the proto- type coupler with a 1.3 GHz ILC-type single-cell cavity at Fermilab will be reported and discussed.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)