Generation of Ultrarelativistic Monoenergetic Electron Bunches via a Synergistic Interaction of Longitudinal Electric and Magnetic Fields of a Twisted Laser

Electron pulse train accelerated by a linearly polarized Laguerre–Gaussian laser beam

“…An important conclusion from our study is that the key features that were previously reported for a CP-LG beam [40,41] are retained in the case of an LP-LG laser beam. It is likely that experimentally it will be easier to generate a high-power LP-LG beam than a high-power CP-LG beams.…”

“…The transverse field is plotted off-axis because it vanishes on the axis of the beam for the considered helical beam. The most striking feature compared to the CP-LG beam examined in [40,41] is the appearance of higher-order harmonics in E y . In contrast to E y , B has a more regular shape.…”

“…It must be stressed that the expulsion is closely tied to the topology of the laser field, which is dominated by the transverse electric and magnetic fields. In two recent publications [ 39 , 40 ] we showed that a CP-LG beam with a properly chosen twist can be used to solve the expulsion problem. The wave-front twist creates a unique accelerating structure dominated by longitudinal laser electric and magnetic fields in the region close to the axis of the beam.…”

“…The longitudinal electric field provides forward acceleration without causing electron divergence, while the longitudinal magnetic field provides transverse electron confinement. It was shown using 3D particle-in-cell (PIC) simulations that a CP-LG beam reflected off a plasma can generate dense bunches of ultra-relativistic electrons via the described mechanism [ 39 , 40 ] . The distinctive features of this acceleration mechanism are the formation of multiple sub- electron bunches, their relatively short acceleration distance (around ) and their high density (in the range of the critical density).…”

Intense harmonic generation driven by a relativistic spatiotemporal vortex beam

“…Concurrent with the progress in high-power lasers [6,7] , the production of intense spatial vortex beams in the relativistic region (> 10 18 W cm −2 for a laser wavelength of ∼ 1 µm) has been theoretically proposed [8][9][10] and demonstrated in laboratories [11][12][13] . Such advanced light sources provide new possibilities for light-matter interactions, such as donut/twist wakefield acceleration [14][15][16] , attosecond electron bunch generation [17][18][19] , formation of a large magnetic field [20] , high harmonics generation (HHG) [12,21,22] , and the spin-orbital interaction [23][24][25][26][27] . In particular, the SAM and/or OAM of fundamental-frequency photons are transferred into high harmonics during HHG.…”