Picosecond electron bunch length measurement by electro-optic detection of the wakefield

Abstract

The longitudinal profile of an 10 nC electron bunch of a few picoseconds duration will be measured by electro-optic detection of the wakefield. The polarization of a short infrared probe laser pulse (derived from the photocathode excitation laser) is modulated in a LiTaO/sub 3/ crystal by the transient electric field of the bunch. The bunch profile is measured by scanning the delay between the laser and the bunch, and is sensitive to head/tail asymmetries. A singleshot extension of the technique is possible using a longer chirped laser pulse.