Dynamics of laser mass-limited foil interaction at ultra-high laser intensities

Abstract

By using three-dimensional particle-in-cell simulations with synchrotron radiation damping incorporated, dynamics of ultra-intense laser driven mass-limited foils is presented. When a circularly polarized laser pulse with a peak intensity of ∼1022 W/cm2 irradiates a mass-limited nanofoil, electrons are pushed forward collectively and a strong charge separation field forms which acts as a “light sail” and accelerates the protons. When the laser wing parts overtake the foil from the foil boundaries, electrons do a betatron-like oscillation around the center proton bunch. Under some conditions, betatron-like resonance takes place, resulting in energetic circulating electrons. Finally, bright femto-second x rays are emitted in a small cone. It is also shown that the radiation damping does not alter the foil dynamics radically at considered laser intensities. The effects of the transverse foil size and laser polarization on x-ray emission and foil dynamics are also discussed.

Dense GeV electron–positron pairs generated by lasers in near-critical-density plasmas

“…To benchmark the simulation results, we also perform a series of reference simulations using the QED-PIC code Virtual Laser–Plasma Lab. (VLPL3741), which can reproduce the main results presented below.…”

“…In extreme laser fields, the radiation damping force363738 exerting on electrons could be expressed as , where e is the charge unit, m e is the electron mass, and β is the normalized electron velocity by the light speed in vacuum c , B and E are the magnetic and electric fields. Here we keep only the main term proportional to in the strong relativistic case.…”

Enhanced electron trapping andγray emission by ultra-intense laser irradiating a near-critical-density plasma filled gold cone

“…21 3 Meanwhile, these electrons are located behind the laser front and effectively confined near the axis of the laser with a transverse size of only μ ∼3 m.Exposed in such an intense laser field, the trapped electrons oscillate significantly in the transverse direction and emit high-energy γ photons in the forward direction. The energy conversion efficiency from the laser to the γ photons is up to 10%, which is much higher than those in the so-called betatron radiation cases [12,13,22,23]. This scheme can serve as a novel table-top γ ray source, and it may benefit the potential experiments for demonstrating the RTE effect at approachable laser intensities in current laboratories.…”

“…During these processes, the radiation field by a charged particle being accelerated or decelerated is sufficiently strong to act back on the particle itself [11]. This is known as radiation reaction (RR), radiation damping, or radiation back-reaction [12][13][14][15][16][17]. When the radiation damping force becomes significant enough to compensate for the laser ponderomotive force, the laser-plasma interaction experiences a great deal of corrections.…”

Effect of electromagnetic pulse transverse inhomogeneity on ion acceleration by radiation pressure

“…The usage of a finite transverse size target, it is called the Mass Limited Target (MLT) or the Reduced Mass Target [32][33][34][35][36][37][38], including the cluster targets [18,39], provide a way for enhancement of the ion energy and acceleration efficiency and a way for high brightness X-ray generation [40]. The irradiation of MLT by enough high intensity lasers is one of the most perspective approaches to develop compact ion accelerators [28,41].…”