First single-shot and non-intercepting longitudinal bunch diagnosticsudfor comb-like beam by means of Electro-Optic Sampling

摘要

At SPARC-LAB,we have installed an Electro-Optic Sampling(EOS)experiment for single shot,non-uddestructive measurements of the longitudinal distribution charge of individual electron bunches.Theudprofile of the electron bunch field is electro-optically encoded into aTi:Sa laser, having 130fs(rms)pulseudlength, directly derived from the photocathode's laser. The bunch profile information is spatiallyudretrieved,i.e.,the laser crosses with an angle of 30 degrees with respect to the normal to the surface of EOudcrystal(ZnTe,GaP)and the bunch longitudinal profile is mapped into the laser's transverse profile.udIn particular,we used the EOS for a single-shot direct visualization of the time profile of a comb-likeudelectron beam,consisting of two bunches, about 100fs(rms)long,sub-picosecond spaced with a totaludcharge of 160pC. The electro-optic measurements(done with both ZnTe and GaP crystals)have beenudvalidated with both RF Deflector (RFD)and Michelson interferometer measurements.