Production of Short Electron Bunches by Slow and Fast Excitations of Longitudinal Bunch-Shape Oscillations

In the Brookhaven AGS, an adiabatic excitation of longitudinal bunch-shape oscillations was successfully used for producing short proton bunches. We applied this method to electron bunches in the Photon Factory (PF) storage ring at KEK. As a result, the electron bunches could be shortened by a factor of about two by applying an rf voltage modulation. It was also found that another fast excitation of oscillations could be used to produce a little shorter bunches than the original slow excitation method. Both experimental and simulation studies are presented.