impedance

Paper	Title	Other Keywords	Page
TUCOB01	Stochastic Cooling Project at the Experimental Storage Ring, CSRe at IMP	pick-up, kicker, simulation, vacuum	64
	J. X. Wu, J. W. Xia, Y. Zhang IMP, Lanzhou F. Caspers CERN, Geneva T. Katayama, F. Nolden GSI, Darmstadt
	Stochastic cooling at the experimental Cooler Storage Ring, CSRe at the Institute of Modern Physics (IMP) in China, will be used mainly for the experiments with radioactive fragment beams. Those RI beams arrive from the fragment separator with the emittance of 20-50 mm. mrad and the momentum spread Dp/p of ± 0.5~1.0 %. The equipped electron cooler is not able to cool down this hot beam within enough short period. Stochastic cooling is effective for these RI beams to reduce the emittance to less than 5 mm.mrad and Dp/p of 5·10-4 within 2-20 sec. After the stochastic pre-cooling, the electron cooling will further cool down the emittance and Dp/p within several seconds. The paper gives the design of the stochastic cooling system and the simulation results. The new developed forward traveling wave structure is presented as well as the measured results of test model.
	Slides
TUPS15	The Stochastic Cooling System of HESR	pick-up, controls, accumulation, kicker	129
	R. Stassen, H. Stockhorst FZJ, Jülich T. Katayama GSI, Darmstadt L. Thorndahl CERN, Geneva
	The HESR is the high energy storage ring (1.5-15 GeV/c) for antiprotons at the FAIR facility (Facility for Antiprotons and Ion Research) in Darmstadt (GSI). Stochastic cooling in the HESR is necessary not only during the experiments to fulfill the beam requirements, but also during the accumulation due to the postponed RESR. Extensive simulations and prototype measurements have been carried out to optimize the HESR stochastic cooling system with the new slot-ring couplers. The system design is now in the final construction phase for the mechanical tank layout and all active RF-components. First results of the optical notch-filter with automated frequency control and the 4-6 GHz slot-ring couplers will be presented.
TUPS16	An Improved Forward Travelling Wave Structure Design for Stochastic Cooling at Experimental Cooler Storage Ring (CSRe) at the Institute of Modern Physics (IMP) in China	pick-up, kicker, simulation, storage-ring	132
	Y. Zhang, J. X. Wu IMP, Lanzhou F. Caspers, L. Thorndahl CERN, Geneva T. Katayama, F. Nolden GSI, Darmstadt
	An improved forward travelling wave (TW) structure as the pick-up/kicker is designed for the stochastic cooling to match the field wave’s (phase) velocity to that of the beam. The theoretical analysis is performed together with the simulations of the propagation characteristics. Using CST Microwave Studio (CST MWS), the simulated results, including phase velocity, characteristics impedance, and distributions of the longitudinal fields, are implemented and compared with the experimented results. The improved forward TW structure can be satisfied the requirements of stochastic cooling project at CSRe, which the phase velocity is closed to 0.70 (matching the desired beam energy of 400 MeV/u) and the characteristics impedance is 17 ohm.