The cleaning required for the time-structured modes of operation is now performed for the 16-bunch and 24 x 8 bunch hybrid modes using a new system. This system is implemented on the bunch-by-bunch feedback system, using the bunch-by-bunch Libera beam position monitor electronics and the wide-bandwidth stripline kicker to perform time-gated cleaning. With this new method, the tuning of the cleaning is much easier, which is particularly beneficial for the 24 x 8 hybrid mode. It also avoids blowing up of the main bunches, which caused an apparent emittance increase during cleaning when the previous system was used.

However, since this cleaning is performed after injection in the storage ring, it is not compatible with the future top-up mode of operation as during the time interval between the injection and the cleaning, parasitic electrons are stored outside the main bunch buckets. This is not a problem when the injections are separated by hours, but will not be acceptable if the interval between the injections becomes much smaller.

A new cleaning system is now being implemented to perform the cleaning 5 to 10 milliseconds after injection in the booster. This system will be based on a system tested a few years ago. The prototype system was not working reliably enough due to the lack of injection-to-injection stability of the tune. To overcome this problem, a fast and accurate measurement system of the dipole and quadrupole currents is being added to the system. From this measurement, the precise value of the frequency of the beam excitation signal, which will kill the parasitic bunches, will be derived for each injection.