Intense terahertz pulses from SPARC_LAB coherent radiation source

Abstract

The linac-based Terahertz source at the SPARC_LAB test facility is able to generate highly intense Terahertz broadband pulses <i>via</i> coherent transition radiation (CTR) from high brightness electron beams. The THz pulse duration is typically down to 100 fs RMS and can be tuned through the electron bunch duration and shaping. The measured stored energy in a single THz pulse has reached 40 μJ, which corresponds to a peak electric field of 1.6 MV/cm at the THz focus. Here we present the main features, in particular spatial and spectral distributions and energy characterizations of the SPARC_LAB THz source, which is very competitive for investigations in Condensed Matter, as well as a valid tool for electron beam longitudinal diagnostics.