2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/83743When a relativistic electron bunch traverses a structure, strong electric fields are induced in its wake. We present measurements of the electric field as a function of time as measured at a fixed location in the beam line. For a 12 nC bunch of duration 4.2 ps FWHM, the peak field is measured >0.5 MV/m. Time resolution of ~5 ps is achieved using electro-optic sampling with a lithium tantalate (LiTaO_3) crystal and a short-pulse infrared laser synchronized to the beam. We present measurements under several different experimental conditions and discuss the influence of mode excitation in the structure.3 pages, 5 figures, LINAC2000 MOC05, LaTeX2eAccelerator PhysicsInstrumentation and Detectorstext