CERN-SL-97-23 AP (1997),
presented at the IEEE Particle Accelerator Conference (session 4V-35), Vancouver, 1997
Beam Echoes in the CERN SPS
O. Brüning, T. Linnecar, F. Ruggiero, W. Scandale, E. Shaposhnikova, and
D. Stellfeld
May 1997
Abstract:
Longitudinal echo signals have been produced in the CERN SPS
by exciting a proton beam at 120 GeV/c with two short RF pulses
separated by a suitable time-delay.
The aim of the experiments was to confirm the analytical
predictions for beam echoes in the SPS and to probe the applicability of
beam echoes for a measurement of the energy distribution and diffusion
coefficients in the accelerator.
We summarise here the results obtained with
bunched and un-bunched beams.
For an un-bunched beam, the excitation frequencies are
at different harmonics of the revolution frequency and result in an echo
response at the difference frequency of the two RF kicks.
For the case of a bunched beam,
the RF kicks are adjusted to excite the quadrupole mode of the bunch motion
and the beam echo response
can also be observed as a quadrupole mode.
F. Ruggiero
Wed May 21 17:11:35 1997