FAST INDICATORS OF LONG-TERM STABILITY

The problem of finding effective fast indicators of long-term stabilit y for single particle betatronic motion in hadron accelerators is cons idered. Two indicators are analysed: the maximal Lyapunov exponent and the variation of the instantaneous tune. An automatic procedure to se lect stable from unstable particles is proposed. The guess of the dyna mic aperture provided by these fast indicators is checked against long -term tracking for the 4D Henon map and for a simplified version of th e SPS lattice used for experiments. Both indicators prove to be very e ffective to determine long-term stability with a limited number of tur ns.