Kornilov, V.

Paper	Title	Page
WEXFI01	Instabilities and Space Charge Effects in High Intensity Ring Accelerators	1882
	O. Boine-Frankenheim, I. Hofmann, V. Kornilov GSI, Darmstadt
	This presentation will review beam dynamics in circular accelerators with high beam intensity and space charge effects. The main focus will be on recent theoretical and experimental results related to collective instabilities and resonance crossing with space charge. In the first part of the presentation, the effect of space charge on collective instability thresholds and impedance budgets will be discussed. In this context the effect of space charge induced mode coupling on the longitudinal microwave instability will be illustrated. The stability of longitudinal bunched beam modes and of transverse dipole modes in the presence of space charge will be discussed. Recent work related to the transverse mode coupling instability (TMCI) with space charge will be reviewed. In the second part of the presentation, "incoherent" space charge effects on transverse nonlinear dynamics issues, like nonlinear resonance crossing, will be reviewed.
	Transparencies
THPCH005	Considerations for the High-intensity Working Point of the SIS100	2793
	G. Franchetti, O. Boine-Frankenheim, I. Hofmann, V. Kornilov, P.J. Spiller, J. Stadlmann GSI, Darmstadt
	In the FAIR project the SIS100 synchrotron is foreseen to provide high-intensity beams of U 28+, including slow extraction to the radioactive beam experimental area, as well as high-intensity p beams for the production of antiprotons. In this paper we discuss the proposal of three different working points, which should serve the different needs: (1) a high intensity working point for U28+; (2) a slow extraction working point (also U28+); (3) a proton operation working point to avoid transition crossing. The challenging beam loss control for all three applications requires a careful account of the effects of space charge, lattice nonlinearities and chromaticity, which will be discussed in detail in this paper. Since tunes are not split by an integer and the injected emittances are different, the Montague stop-band needs to be avoided. Moreover, final bunch compression for the U beam requires a sufficiently small momentum spread, and the risk of transverse resisitive wall instabilities poses further limitations on our choice of working points.