The Damper for the Transverse Instabilities of the SPS

Abstract

For beam intensities above 1Ol2 protons per pulse in the SPS, collective transverse beam instabilities develop with frequencies between 15 kHz and 3 MHz because of the resistive wall effect of the vacuum ' chamber]), An active feedback system2) with an electrostatic deflector has been installed in the SPS for damping the resistive wall instabilities in both the vertical and horizontal planes,

Large angle beamstrahlung as a beam–beam monitoring tool

“…SM radiation was first observed in Ref. [10]. In regions where SM radiation dominates, such as at large angle (γθ >> 1), which are the only ones relevant to this paper, three properties are of interest:…”

Review of Feedback Systems

“…For a transverse feedback the signal of two pickups approximately 90° in betatron phase apart can be combined to achieve a position signal which is shifted by an arbitrary phase. This method has been used in the transverse feedback of the SPS [21] and LEP [22]. The correction signal is attained on the analog level.…”