Electron Self-Injection into an Evolving Plasma Bubble: The Way to a Dark Current Free GeV-Scale Laser Accelerator

Generation of Superponderomotive Electrons in Multipicosecond Interactions of Kilojoule Laser Beams with Solid-Density Plasmas

“…So electrons always experience longer and larger antidephasing than dephasing. From the viewpoint of a non-stationary Hamiltonian theory [31][32][33][34], antidephasing (resulting in a high-energy electron acceleration) may be interpreted as a reduction of the "moving-frame" Hamiltonian, , , where γ e = (1 + p 2 /m e 2 c 2 + a 0 2 /2) 1/2 .…”

Electron self-injection into an evolving plasma bubble: Quasi-monoenergetic laser-plasma acceleration in the blowout regime

“…As a result of this evolution, sheath electrons can penetrate into the bubble near its rear, synchronize with it (i.e., obtain the longitudinal momentum p k % c g m e c) and then travel inside the cavity, continuously gaining energy. 18,[21][22][23][24][25][26][27] Self-injection eliminates the need for an external injector and, thus, is favorable for the accelerator design. It ties the electron beam quality to the self-consistent nonlinear evolution of the driver.…”

Sub-millimeter-scale, 100-MeV-class quasi-monoenergetic laser plasma accelerator based on all-optical control of dark current in the blowout regime

“…The QME bunch consists of particles injected during the period of the most rapid bubble expansion between z = 0.215 and 0.35 mm. As the bubble stabilizes between z = 0.35 and 0.5 mm, electron energy spread drops below 10% (via the mechanism of phase space rotation [6,7]) and further stays at this level. Bubble expansion through the Stage II creates energy tail in both simulations.…”

“…Electron cavitation relaxes limitations on the charge imposed by beam loading [4]. The bubble readily traps relativistic electrons from its sheath [1,5,6,7], reducing the technical complexity of the experiment while preserving flexibility in parameters [2,5,7]. Robustness of self-injection is rooted in the adiabatically slow evolution of the bubble, which, in turn, is tied to the nonlinear optical evolution of the driver [5,6,7,8].…”

“…The bubble readily traps relativistic electrons from its sheath [1,5,6,7], reducing the technical complexity of the experiment while preserving flexibility in parameters [2,5,7]. Robustness of self-injection is rooted in the adiabatically slow evolution of the bubble, which, in turn, is tied to the nonlinear optical evolution of the driver [5,6,7,8]. Therefore, controlling relativistic optical phenomena, such as self-focusing [9], phase self-modulation and pulse self-compression [10], provides an opportunity to manage the fully kinetic self-injection process and optimize electron beam parameters [8,11].…”