“Light Sail” Acceleration Reexamined

Abstract

The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for "optimal" values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple "light sail" model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

Radiation-Pressure Acceleration of Ion Beams from Nanofoil Targets: The Leaky Light-Sail Regime

“…1(b). Only the ions initially located in the compression region (d 1 < z < l 0 ) at the rear side are bunched into a highdensity layer by the leading edge of E z , while the others undergo Coulomb explosion by the trailing part of E z [12]. Afterwards, the electron and ion layers combine together as a quasineutral plasma slab pushed by the laser, known as ''light-sail'' (LS) RPA regime [13].…”

“…1(a) or 1(b) break down. Consequently, theoretical models of either ''phase-stable'' [5,9] or ''cyclic'' [4,12] acceleration no longer apply to this new regime, which we call ''leaky light-sail (LS)'' RPA. In this Letter, we present theoretical and numerical studies on this new regime, where a subskin-depth nm foil (nanofoil) is irradiated by CP laser pulses.…”

“…ensuring not all electrons are blown out [6,12]. The simulation space (15 Â 12 m) is composed of 30000 Â 3000 cells along z and x directions.…”

High-energy monoenergetic protons from multistaged acceleration of thin double-layer target by circularly polarized laser

“…11,12,35,36 Each foil cell contains 400 simulation particles. Absorbing boundary conditions are used for both the electromagnetic fields and the simulation particles.…”

The ELIMED transport and dosimetry beamline for laser-driven ion beams

“…Since the first experiments on laser-matter interaction, wide theoretical and experimental progresses have been carried out, confirming the possibility to accelerate multi-MeV ion beams from the interaction of high-intensity laser pulses (from 1018 to 1020 W/cm2) on thin solid targets [3][4][5]. So far different acceleration regimes [6][7][8][9][10][11], such as the Target Normal Sheath Acceleration (TNSA) [12][13][14], the Radiation Pressure Acceleration (RPA) [15][16][17] and the Break-Out Afterburner (BOA) [18], have been studied and several experimental results, obtained mainly within the TNSA regime, have been reported in the literature [12][13][14]. Some of the peculiarities of the accelerated protons might be of interest for different kind of applications, including the medical ones.…”