Preliminary operational experiences of a bunch-by-bunch transverse feedback system at the Australian synchrotron

Abstract

The Australian Synchrotron storage ring has a high resistive wall impedance in the vertical plane. Presently the instability from this impedance is being controlled by increasing the vertical chromaticity. However new in-vacuum insertion devices that significantly increase the ring impedance will demand chromatic corrections beyond the capabilities of the sextupole magnets. A transverse bunch-by-bunch (BBB) feedback system has been commissioned to combat the vertical instability and provide beam diagnostics. A high frequency narrow band mode that could not be damped was initially encountered with IVUs at specific gaps preventing the system from being implemented during user beam. Study into ..