• V.Smaluk for VEPP-4M Team
  Budker Institute of Nuclear Physics, Novosibirsk, Russia

An electron-positron collider VEPP-4M is under operation now at BINP. The main goal of the present run is the precise measurement of mass of y -family resonances and t -lepton with the help of resonant depolarization technique. The status and recent results of the experiment are reviewed.

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• V.P.Cherepanov, E.N.Dementev, A.S.Medvedko, V.V.Smaluk, D.P.Sukhanov
  Budker Institute of Nuclear Physics, Novosibirsk, Russia

The fast head-tail and coupled-bunch instabilities are the reasons of the increased beam emittance, energy spread and of the operating current limitations and beam loss. For suppression of any excited transverse mode of the beam oscillation the wide-band bunch-by-bunch digital feedback system have been developed and installed on the VEPP-4M storage ring. A description of the system parameters and architectures, of the available diagnostic tools and of the experimental results is given.

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• V.Smaluk
  BINP SB RAS, Novosibirsk

• D. Einfeld
  ALBA, Bellaterra, Spain

In the framework of the Spanish Light Source CELLS project, an analysis of coupling impedance of the ALBA storage ring has been carried out. Broad-band impedance has been evaluated using the MAFIA code and analytical formulae, for various components of the ALBA vacuum chamber, such as cross section transitions, bellows, button-electrodes, strip-lines, high-order modes of RF cavities, etc.

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