Generation of attosecond electron bunches

A process for obtaining attosecond electron microbunches is presented. The electron beam is produced in a 5 MeV photocathode gun injector with emittance of 2.5 mm-mrad, energy spread of 15 keV, peak current of 100 A, and pulse length of 10 ps. The choice of these parameters is based on data gathered at modern state-of-the-art photocathode gun facilities The electrons are then accelerated to 100 MeV in a linear accelerator and are injected into an undulator. The light pulse from the laser is also sent into the undulator and co-propagates the undulator together with the electron bunch. A result from the computer simulation of energy modulation performed with code GINGER is given. We show a small part of the electron bunch extended over 10 fs. Electron energy modulation occurred all over the entire electron bunch