Slide 1

Peter Spiller, GSI, ICFA workshop, 17.10.2004 Optimization of SIS100 Lattice and Dedicated Collimation System P. Spiller, GSI ICFA 2004 Bensheim 18.10.04 Slide 2 Peter Spiller, GSI, ICFA workshop, 17.10.2004 Lattice Optimization - General CDR triplet lattice with 4 dipoles per cell (Acceptance : 100 x 55 mm mrad) Doublet lattice with 2 dipoles per cell (Acceptance : 170 x 50 mm mrad ) Maximum beam acceptance (small aperture magnets for fast ramping) Dispersion free straight sections (no transv.-longit. coupling in rf systems) Low dispersion in the arcs (momentum spread during compression) D x = 2.5 m Six superperiods (space for large tune spread and long storage time) Slide 3 Peter Spiller, GSI, ICFA workshop, 17.10.2004 U 28+ : Reference Ion of the FAIR Project Present Intensity in SIS12/18 2.5 x 10 9 U 73+ -ions /cycle Planned Intensity in SIS12 Booster Operation 2.5 x 10 11 U 28+ -ions /cycle Planned Intensity in SIS100/300 1 x 10 12 U 28+ -ions /cycle The step to highest heavy ion beam intensities requires medium charge states. Slide 4 Peter Spiller, GSI, ICFA workshop, 17.10.2004 History of U 28+ operation at GSI Slide 5 Peter Spiller, GSI, ICFA workshop, 17.10.2004 Life Time and Vacuum Instability Beam losses induced by a dynamic vacuum or a vacuum instability is the most crucial item for achieving the goals of the new facility. Slide 6 Peter Spiller, GSI, ICFA workshop, 17.10.2004 Residual Gas Pressure Dynamics Fast variations (time scale s) Slow variations (time scale s) Slide 7 Peter Spiller, GSI, ICFA workshop, 17.10.2004 Vacuum Stabilization General Short cycle time and short sequences SIS12 :10 T/s - SIS100 : 4 T/s (new network connection in preparation) Enhanced pumping power, optimized spectrum (Actively cooled magnet chambers 4.5 K, NEG coating (local and distributed) Localization of losses and controle of desorption gases Prototype desorption collimator installed in S12 Low-desorption rate materials Desorption rate test stand in operation wedge collimator increased pressure ion beam cryo pump Slide 8 Peter Spiller, GSI, ICFA workshop, 17.10.2004 Loss MechanismLocationTime scaleAngleEnergy Tails and Halo due to Resonances, non-linear dynamics etc. (higher order dynamics) Everywhere but mainly on acceptance limiting devices (in straight sections) (both sides) SecondsEnvelope angle (