Thorndahl, L.

Paper	Title	Page
TUIOB02	Simulations of Stochastic Cooling of Antiprotons in the Collector Ring CR	58
	C. Dimopoulou, A. Dolinskii, T. Katayama, F. Nolden, C. Peschke, M. Steck GSI, Darmstadt D. Möhl, L. Thorndahl CERN, Geneva
	The Collector Ring at FAIR will be equipped with pertinent stochastic cooling systems in order to achieve fast cooling of the hot secondary beams, antiprotons and rare isotopes, thus profiting from the repetition rate of the SIS100 synchrotron. Detailed simulations of the system performance are needed for optimization as well as input for the users of the CR pre-coooled beams, e.g. HESR. We presently focus on the antiproton cooling in the band 1-2 GHz. After a short overview, results from Fokker-Planck simulations with the CERN code of the momentum cooling of antiprotons will be presented. The performance of the betatron cooling of antiprotons, which has to proceed simultaneously with the momentum cooling, was calculated separately by means of an analytical model. First results and their implications will be discussed, including an outlook to future simulation work.
	Slides
TUPS15	The Stochastic Cooling System of HESR	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	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.