Collective effects in the VEPP-3 storage ring

Lengthening of a single bunch has been investigated in the VEPP-3 storage ring at different energies for a beam current up to 100 mA. The bunch length was measured using an optical diagnostic system. The current dependences of the transverse beam size, synchronous phase shift, and the coherent and incoherent synchrotron tune shift have been measured. The experimental data are in agreement with the model of longitudinal potential well distortion. The real and imaginary parts of the longitudinal coupling impedance are deduced from measured data. >