Study of the measurement for electron bunches and the irradiation effect by femtosecond electro-optic sampling

The temporal electric field distribution by the propagating picosecond electron bunches was measured by using electro-optic sampling in a ZnTe crystal with the near-infrared femtosecond laser pulses. The temporal profile of the electron bunches with a pulse width of 1.0 ps was measured. The signal with a reversed polarity to the peak by the electron bunch is observed and ascribed to the ionization and electron current which recovers the charge-up induced by the electron bunch excitation.