High-gradient modulation of microbunchings using a minimized system driven by a vortex laser

This study entailed the development of a high-gradient modulation of microbunching for traditional radiation frequency accelerators using a minimized system driven by a relativistic Laguerre-Gaussian (LG) laser in three-dimensional particle in-cell (PIC) simulations. It was observed that the LG laser could compress the transverse dimension of the beam to within a 0.7 mu m radius (divergence approximate to 4.3 mrad), which is considerably lower than the case tuned by a Gaussian laser. In addition, the electron beam could be efficiently modulated to a high degree of bunching effect (>0.5) within-21 fs (-7 mu m) in the longitudinal direction. Such a high-gradient density modulation driven by an LG laser for pre-bunched, low-divergence, and stable electron beams provides a potential technology for the system minimization of X-ray free-electron lasers (XFELs) and ultrashort-scale (attosecond) electron diffraction research.