Controlled Longitudinal Emittance Blow-up in the SPS as Injector and LHC Test-Bed

A controlled blow-up of the longitudinal emittance of the LHC beam is necessary in the SPS as well as in LHC. During several machine developments in 2003 the LHC beam in the SPS was excited through the phase loop with bandwidth-limited noise. This method is suitable for the SPS as well as for LHC. This way it was possible to achieve a controlled bunch length increase by a factor of more than two, corresponding to an emittance increase by a factor of about four. The following note describes the details of the machine developments, the hardware used, and the influence of parameters like timing, bandwidth, frequency and amplitude of the excitation signal on the resulting blow-up