The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CPAPER AU - Kelly, M.P. AU - Barcikowski, A. AU - Conway, Z.A. AU - Horan, D. AU - Kedzie, M. AU - Kim, S.H. AU - Kutsaev, S.V. AU - Ostroumov, P.N. AU - Rathke, J. TI - 20 kW CW Power Couplers for the APS-U Harmonic Cavity J2 - Proc. of International Conference on RF Superconductivity (SRF2015), Whistler, BC, Canada, Sept. 13-18, 2015 AB - 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. PB - JACoW CY - Geneva, Switzerland SP - 1346 EP - 1348 KW - cavity KW - Windows KW - operation KW - storage-ring KW - electron DA - 2015/12 PY - 2015 SN - 978-3-95450-178-6 DO - 10.18429/JACoW-SRF2015-THPB088 UR - http://srf2015.vrws.de/papers/thpb088.pdf ER -