SRF2011 - List of Authors (Kolomiets, A.)

Paper	Title	Page
MOPO026	β = 0.285 Half-Wave Resonator for FRIB	132
	P.N. Ostroumov, Z.A. Conway, R.L. Fischer, S.M. Gerbick, M.P. Kelly, A. Kolomiets, B. Mustapha, A. Ortega Bergado ANL, Argonne, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357and WFO 85Y64 Supported by Michigan State University We have developed an optimized electromagnetic and mechanical design of a 322 MHz half-wave resonator (HWR) suitable for acceleration of ions in the post-stripper section of the Facility for Rare Isotope Beams (FRIB). The cavity design is based on recent advances in SRF technology for TEM-class structures being developed at ANL. Highly optimized EM parameters were achieved using an ”hourglass” cavity shape for the HWR. This new design will be processed with a new HWR horizontal electropolishing system after all mechanical work on the cavity including the welding of the helium vessel is complete. Recently, this procedure was successfully tested on a quarter wave resonator developed for the ATLAS Upgrade which achieved peak surface fields of 70 MV/m and 10⁵ mT. Following these results we propose to operate the HWR with a 2.6 MV accelerating voltage per cavity at the optimal ion velocity of β = 0.285. Fabrication of the cavity can be started immediately as soon as funding is available.

MOPO044	Electromagnetic Design Optimization of a Half-Wave Resonator	192
	B. Mustapha, Z.A. Conway, A. Kolomiets, P.N. Ostroumov ANL, Argonne, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357and WFO 85Y64 Supported by Michigan State University The optimization procedure developed for the electromagnetic (EM) design of the ATLAS Upgrade quarter-wave resonator (QWR) [1] has now been successfully tested. The prototype QWR achieved record peak surface fields of 70 MV/m and 10⁵ mT and is capable of providing 4.4 MV, far exceeding the design voltage of 2.5 MV. We have developed and applied a similar procedure for the EM design of a 322 MHz - β ~ 0.29 half-wave resonator (HWR) for the medium energy section of the FRIB driver linac. The optimization path and the final results will be presented and discussed. The choice of aperture and its effect on the EM design parameters will be discussed. A comparison between equivalent half-wave and single-spoke resonators will also be presented. The transition from the electromagnetic model in MWS to the engineering model in Inventor was carefully studied as it may affect both the EM design parameters and the cavity fabrication. * “Electromagnetic Optimization of a Quarter-Wave Resonator” B. Mustapha and P. Ostroumov, Proceedings of Linac-10, Tsukuba, Japan.

Paper

Title

Page

β = 0.285 Half-Wave Resonator for FRIB

132

P.N. Ostroumov, Z.A. Conway, R.L. Fischer, S.M. Gerbick, M.P. Kelly, A. Kolomiets, B. Mustapha, A. Ortega Bergado
ANL, Argonne, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357and WFO 85Y64 Supported by Michigan State University
We have developed an optimized electromagnetic and mechanical design of a 322 MHz half-wave resonator (HWR) suitable for acceleration of ions in the post-stripper section of the Facility for Rare Isotope Beams (FRIB). The cavity design is based on recent advances in SRF technology for TEM-class structures being developed at ANL. Highly optimized EM parameters were achieved using an ”hourglass” cavity shape for the HWR. This new design will be processed with a new HWR horizontal electropolishing system after all mechanical work on the cavity including the welding of the helium vessel is complete. Recently, this procedure was successfully tested on a quarter wave resonator developed for the ATLAS Upgrade which achieved peak surface fields of 70 MV/m and 10⁵ mT. Following these results we propose to operate the HWR with a 2.6 MV accelerating voltage per cavity at the optimal ion velocity of β = 0.285. Fabrication of the cavity can be started immediately as soon as funding is available.

MOPO044

Electromagnetic Design Optimization of a Half-Wave Resonator

192

B. Mustapha, Z.A. Conway, A. Kolomiets, P.N. Ostroumov
ANL, Argonne, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357and WFO 85Y64 Supported by Michigan State University
The optimization procedure developed for the electromagnetic (EM) design of the ATLAS Upgrade quarter-wave resonator (QWR) [1] has now been successfully tested. The prototype QWR achieved record peak surface fields of 70 MV/m and 10⁵ mT and is capable of providing 4.4 MV, far exceeding the design voltage of 2.5 MV. We have developed and applied a similar procedure for the EM design of a 322 MHz - β ~ 0.29 half-wave resonator (HWR) for the medium energy section of the FRIB driver linac. The optimization path and the final results will be presented and discussed. The choice of aperture and its effect on the EM design parameters will be discussed. A comparison between equivalent half-wave and single-spoke resonators will also be presented. The transition from the electromagnetic model in MWS to the engineering model in Inventor was carefully studied as it may affect both the EM design parameters and the cavity fabrication.
* “Electromagnetic Optimization of a Quarter-Wave Resonator” B. Mustapha and P. Ostroumov, Proceedings of Linac-10, Tsukuba, Japan.