Dephasingless laser wakefield acceleration in the bubble regime

Abstract

Laser wakefield accelerators (LWFAs) have electric fields that are orders of magnitude larger than those of conventional accelerators, promising an attractive, small-scale alternative for next-generation light sources and lepton colliders. The maximum energy gain in a single-stage LWFA is limited by dephasing, which occurs when the trapped particles outrun the accelerating phase of the wakefield. Here, we demonstrate that a single space–time structured laser pulse can be used for ionization injection and electron acceleration over many dephasing lengths in the bubble regime. Simulations of a dephasingless laser wakefield accelerator driven by a 6.2-J laser pulse show 25 pC of injected charge accelerated over 20 dephasing lengths (1.3 cm) to a maximum energy of 2.1 GeV. The space–time structured laser pulse features an ultrashort, programmable-trajectory focus. Accelerating the focus, reducing the focused spot-size variation, and mitigating unwanted self-focusing stabilize the electron acceleration, which improves beam quality and leads to projected energy gains of 125 GeV in a single, sub-meter stage driven by a 500-J pulse.

Laser driven wake wave in pair-ion electron plasma with inclusion of ion dynamics

“…In the wake, both radial and axial pondermotive force are generated to accelerate the electrons. One of the significant process in this DLA or LWFA process is the formation of bubble or blow-out region [29,[39][40][41][42]. When a highly intense laser pulse with short duration, interacts with the plasma, the plasma electrons are completely expelled out from the axial region to form a ion cavity.…”