Improvements to the SPS Slow Extraction for High Intensity Operation

Slow extraction using the third-integer resonance and thin electrostatic septa as used in the SPS to serve the North Area is a process with inherent beam loss. For high-flux 400 GeV protons, the beam losses result in high machine activation, reduced component lifetime and severe limitations on personnel access and maintenance. The instantaneous and integrated loss levels are strong limitations on the annual attainable POT for present operation and for the much higher fluxes requested by SHiP at the proposed BDF facility. In this report the present constraints and potential improvements to the slow extraction system in the SPS are described along with the recent theoretical studies and practical implementation of prospective operational improvements. Machine results of testing of new extraction loss reduction techniques and hardware are presented in the context of SHiP POT requests, SPS BDF and the PBC project and the potential extraction loss reduction factor is evaluated with an outlook to future high intensity operation. The prospects of deployment on the present operational beams and the resulting improvement factors are discussed.