  The positron beam in the DAFNE e+/e- collider has always been suffering from
strong e-cloud instabilities. In order to cope with them, several approaches
have been adopted along the years: flexible and powerful bunch-by-bunch
feedback systems, solenoids around the straight sections of the vacuum chamber
and, in the last runs, e-cloud clearing electrodes inside the bending and
wiggler magnets. Of course classic diagnostics tools have been used to evaluate
the effectiveness of the adopted measures and the correct setup of the devices,
in order to acquire total beam and bunch-by-bunch currents, to plot in real
time synchrotron and betatron instabilities, to verify the vertical beam size
enlargement in collision and out of collision. Besides, to evaluate the
efficacy of the solenoids and of the clearing electrodes versus the instability
speed, the more powerful tools have been the special diagnostics routines
making use of the bunch-by-bunch feedback systems to quickly compute the growth
rate instabilities and the bunch-by-bunch tune spread in different beam
conditions.
