A cure for the energy spread increasing related bunch lengthening in electron storage rings

Having revealed the cause of the energy spread increasing and the corresponding bunch lengthening in electron storage rings previously, in this paper, we will propose a cure for the suppression of these collective effects. It is suggested to install an active RF cavity in the ring with the working RF wavelength about four to five times the RMS bunch length. The limitation about this cure is also discussed. Finally, in the postscript, we will give an empirical bunch lengthening equation and compare the analytical results with some experimental results