ILC DR instability simulations CMAD a tracking and e-cloud beam instability parallel code (M.P. SLAC) Taking MAD(X) optics file at input, thus tracking the beam in a real lattice and applying the interaction beam-electron cloud over the whole ring New simulations: finding higher threshold in DCO4 then in previous DCO2 lattice (in DCO2 we set at input 10% beam jitter that lowered threshold..) DC04 lattice: 6.4 km ring DSB3 lattice: 3.2 km ring AVERAGE RING DENSITY (M. Pivi, SLAC)

ILC DR instability simulations CMAD a tracking and e-cloud beam instability parallel code (M.P. SLAC) Taking MAD(X) optics file at input, thus tracking the beam in a real lattice and applying the interaction beam-electron cloud over the whole ring New simulations: finding higher threshold in DCO4 then in previous DCO2 lattice (in DCO2 we set at input 10% beam jitter that lowered threshold..) DC04 lattice: 6.4 km ring DSB3 lattice: 3.2 km ring DENSITY IN MAGNETS (M. Pivi, SLAC)

Still needed: build-up simulations in quadrupoles Given the same current and bunch distance we expect similar or even higher instability threshold for the shorter ring In preparation for recommendation of ILC Damping Ring length, proposing 2 more Webex meetings before LCWS10: March 9 March 23