Analysis of the electromagnetic fields and electron acceleration in the bubble regime of the laser-plasma interaction

Abstract

An analytical model for the electromagnetic fields in the bubble regime of the interaction of ultrahigh-intensity laser with plasma is given. The two-dimensional model is based on the results of particle-in-cell simulation and includes the bubble front region. It is used to consider the generation of dense ultrashort quasimonoenergetic high-energy electron bunches. The resulting bunch parameters agree fairly well with those from the simulation.

Bubble core field modification by residual electrons inside the bubble

“…Recently, some research groups, e.g., Kostyukov et al, 4 Lotov, 6 Lu et al, 9,10 and Xie et al 14 have made some analysis on the bubble core fields as well as bubble front fields and concluded a linear scaling law of bubble core fields on coordinates. It seems that the validity of this linear law have been confirmed by many particle-incell ͑PIC͒ simulations, however, the slopes of the linear fields always have some discrepancies between PIC and theoretical results, in particular for the transverse electromagnetic fields.…”

“…1 Since then many works have been contributed to this interesting research field of laser-driven plasma wakefield acceleration, particularly in the research direction of the so-called bubble regime, [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] which can produce nearly monoenergetic fast electrons. In this regime, the ponderomotive force of a short intense laser pushes away almost all the plasma electrons and forms an electron cavity or bubble.…”

Electrons trajectories around a bubble regime in intense laser plasma interaction

“…In particular, the nonlinear dynamics of electrons plays a key role on the electron acceleration to produce a quasi-monoenergetic electron bunch in the bubble regime, where the ponderomotive force of laser pulse pushes away the plasma electrons, so that a nonlinear soliton-like structure of electron density, i.e., plasma cavity or bubble is formed. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] There is a very large space-charge separation electrostatic field in the bubble regime, which can efficiently trap and accelerate the electrons at the bottom of the bubble. For example, in Ref.…”

Influence of a Magnetic Guide Field on Injection in Wakefield Acceleration

“…Then one has to solve the following two equations: [6,7]. Considering that one has a cylindrical symmetry, the solution is…”

“…Dimensionless units are used is introduced. In the laboratory frame, the following convenient gauge is used: [6][7][8][9]. Inside the bubble one can consider that 0…”