Orateur
Description
Terahertz (THz) acceleration is a promising approach toward compact electron accelerators, combining high accelerating fields with structures significantly smaller than conventional radiofrequency systems. Within the TWAC (Terahertz Wave Accelerating Cavity) Project , my PhD focuses on the modelling and characterization of the dielectric-lined accelerating waveguide “ZITA”.
The structure is designed to guide a THz pulse together with an electron bunch while providing a longitudinal electric field suitable for acceleration. A key requirement is to control the electromagnetic dispersion so that the phase velocity of the accelerating mode, in particular the TM01 mode, is matched to the electron velocity.
A semi-analytical model has been developed to calculate the supported modes, cutoff frequencies, dispersion relations, and phase and group velocities for different waveguide geometries. Experimental characterization of prototypes is performed, from which the propagation properties can be determined and compared with the model.
This comparison is used to identify the modes present in the structure and to understand differences between the ideal design and the real device.
The next stage of the work will extend this validated description toward THz pulse propagation and electron-field interaction, with the aim of studying synchronism, interaction length, energy gain, and ultimately beam-quality evolution. The overall objective is to provide an experimentally supported model that can be used for future THz-driven acceleration experiments.