Kinetic and finite ion mass effects on the transition to relativistic self-induced transparency in laser-driven ion acceleration

Abstract

We study kinetic effects responsible for the transition to relativistic self-induced transparency in the interaction of a circularly-polarized laser-pulse with an overdense plasma and their relation to hole-boring and ion acceleration. It is demonstrated using particle-in-cell simulations and an analysis of separatrices in single-electron phase-space, that ion motion can suppress fast electron escape to the vacuum, which would otherwise lead to transition to the relativistic transparency regime. A simple analytical estimate shows that for large laser pulse amplitude $a_0$ the time scale over which ion motion becomes important is much shorter than usually anticipated. As a result, the threshold density above which hole-boring occurs decreases with the charge-to-mass ratio. Moreover, the transition threshold is seen to depend on the laser temporal profile, due to the effect that the latter has on electron heating. Finally, we report a new regime in which a transition from relativistic transparency to hole-boring occurs dynamically during the course of the interaction. It is shown that, for a fixed laser intensity, this dynamic transition regime allows optimal ion acceleration in terms of both energy and energy spread.

arXiv commentAdded new material. 15 pages, 12 figures

References in corpus (19)

• Ion acceleration by superintense laser-plasma interaction
• Radiation Pressure Dominate Regime of Relativistic Ion Acceleration
• Femtosecond x rays from laser-plasma accelerators
• Laser acceleration of ion bunches at the front surface of overdense plasmas
• Radiation Pressure Acceleration of Ion Beams Driven by Circularly Polarized Laser Pulses
• Multiple colliding electromagnetic pulses: a way to lower the threshold of $e^{+}{e}^{-}$ pair production from vacuum
• Hole boring in a DT pellet and fast ion ignition with ultra-intense laser pulses
• Direct observation of the injection dynamics of a laser wakefield accelerator using few-femtosecond shadowgraphy
• Coherent control of plasma dynamics
• Effect of electron heating on self-induced transparency in relativistic intensity laser-plasma interaction
• Relativistic Self-Induced Transparency Effect During Ultraintense Laser Interaction with Overdense Plasmas: Why It Occurs and Its Use for Ultrashort Electron Bunch Generation
• Synchronized ion acceleration by ultraintense slow light
• Relativistically Induced Transparency Acceleration (RITA) of Protons and Light-ions with Ultrashort Laser Interaction with Heavy-ion Plasma Density Gradient
• Backward-Propagating MeV Electrons in Ultra-Intense Laser Interactions: Standing Wave Acceleration and Coupling to the Reflected Laser Pulse
• Energy dispersion in radiation pressure accelerated ion beams
• Backward-propagating MeV electrons from $10^{18}$ W/cm${}^2$ laser interactions with water
• Suppressing longitudinal double-layer oscillations by using elliptically polarized laser pulses in the hole-boring radiation pressure acceleration regime
• Proton acceleration by a pair of successive ultraintense femtosecond laser pulses
• Ion Acceleration via "Nonlinear Vacuum Heating" by the Laser Pulse Obliquely Incident on a Thin Foil Target

Cited by in corpus (8)

• Enhanced laser-driven proton acceleration via improved fast electron heating in a controlled pre-plasma
• Acceleration of spin-polarized proton beams via two parallel laser pulses
• Effects of oblique incidence and colliding pulses on laser-driven proton acceleration from relativistically transparent ultrathin targets
• Enhanced target normal sheath acceleration with a grooved hydrocarbon target
• Particle-in-Cell modeling of a potential demonstration experiment for double pulse enhanced target normal sheath acceleration
• Laser-Plasma Ion Beam Booster Based on Hollow-Channel Magnetic Vortex Acceleration
• Intensity and Dimensionality-Dependent Dynamics of Laser-Proton Acceleration in 1D, 2D, and 3D Particle-in-Cell Simulations
• Enhancement of laser-driven ion acceleration in non-periodic nanostructured targets