Speaker
Description
The beam abort system for the current Swiss Light Source (SLS) is based on inverting the RF phase to decelerate the stored beam. The loss process was assumed to evenly spread out the stored beam around the ring. However, it is actually localised at longitudinal positions where the dispersive orbit meets the machine aperture. For the SLS, these losses mainly occur at the septum and triple-bend-achromat arc sections. For the SLS 2.0 with its seven-bend-achromat lattice and thus much lower dispersion in the arcs, tracking simulations show that these losses are localised at a superconducting super bend and an in-vacuum insertion device. Due to this unfortunate dispersive loss distribution, the small beam size, the fragile vacuum chamber and the stored beam energy of 1 kJ, a more controlled beam abort is desired. In case of an RF failure, the beam abort system must dump the beam safely before the critical dispersive orbit is reached. A fast beam dump controller with dedicated inputs for fast systems such as the low-level RF and fast feedback systems is foreseen for triggering the required emergency beam dump procedure. The majority of the well over 6000 machine interlock signals will pass through the slow, programmable-logic-controller-based machine interlock system. Here the sheer amount of signals will pose a challenge.
