Phase-locked laser-wakefield electron acceleration

Abstract

Subluminal and superluminal light pulses have attracted a considerable attention in the past decades [1][2][3][4] opening perspectives in telecommunications, optical storage, and fundamental physics 5 . Usually achieved in matter, superluminal propagation has also been demonstrated in vacuum with quasi-Bessel beams 6, 7 or Spatio-Temporal Couplings 8, 9 (STCs). While in the first case the propagation was diffraction-free, but with hardly controllable pulse velocities and limited to moderate intensities, in the second a high tunability was achieved, yet with significantly lengthened pulse durations. Here, we report on a new concept that extends these approaches to relativistic intensities and ultra-short pulses by mixing STCs and quasi-Bessel beams to control independently the light velocity and intensity. When used to drive a Laser-Plasma Accelerator 10 (LPA), this concept leads to a new regime, dephasing-free, where the electron beam energy gain increases by more than one order of magnitude.Electrical breakdown limits electric fields in radio frequency accelerators to about 100 MeV/m. LPAs commonly overcome this restriction by focusing ultra-short laser pulses in a gas to generate

Optical wave-packet with nearly-programmable group velocities

“…In this case, the propagating time-dependent motions can be well controlled by carefully optimizing the shape of the pulse-front deformation, creating optical wave-packets with unusual motion forms. As regards applications, we believe it can be used in some propagating velocity matched experiments, such as bio-imaging, particle-manipulation, particle acceleration, and radiation generation [75][76][77] , and the high spatiotemporal controllability could also offer new opportunities for fundamental studies in optics and physics.…”

Multi-GeV Laser Wakefield Electron Acceleration with PW Lasers

“…Besides the challenge of producing stable long-distance channels [50], curved channel technology will provide a useful method to control the directionality of electron beams and laser pulses [51]. In addition, recent theoretical and numerical studies proposed to overcome the dephasing length of LWFA, so-called phase-locked [52] or dephasingless [53] LWFA, by adapting the superluminal velocity of focal spot movement [54], which can be a way to maximize electron energy for given laser power.…”

Optimization of Electron Beams Based on Plasma-Density Modulation in a Laser-Driven Wakefield Accelerator

“…However, some of these methods demand sophisticated configurations, and the produced e beams are deficient in charge, energy spread, or peak energy, which hinder their practical applications. Recently, some significant studies have been reported to improve the specific qualities of e beams, including the peak energy [16][17][18][19][20], the energy spread [21][22][23][24][25][26], the brightness [24,27,28], the reproducibility [29][30][31], etc. More considerable research efforts, however, are still needed to focus on generating reproducible high-quality electrons for table-top light sources, which should have a broad-ranging impact across multiple scientific fields.…”