Maximum Proton Energy above 85 MeV from the Relativistic Interaction of Laser Pulses with Micrometer ThickCH2Targets

Abstract

We present a study of laser-driven ion acceleration with micrometer and submicrometer thick plastic targets. Using laser pulses with high temporal contrast and an intensity of the order of 10^{20} W/cm^{2} we observe proton beams with cutoff energies in excess of 85 MeV and particle numbers of 10^{9} in an energy bin of 1 MeV around this maximum. We show that applying the target normal sheath acceleration mechanism with submicrometer thick targets is a very robust way to achieve such high ion energies and particle fluxes. Our results are backed with 2D particle in cell simulations furthermore predicting cutoff energies above 200 MeV for acceleration based on relativistic transparency. This predicted regime can be probed after a few technically feasible adjustments of the laser and target parameters.

Experimental demonstration of a compact epithermal neutron source based on a high power laser

“…The input flux of fast neutrons can be significantly enhanced by increasing the energy and number of incident ions on the catcher. Order of magnitude higher fast neutron fluxes than produced in the current experiment have been already reported [2][3][4], and, in principle, can be further improved upon by taking advantage of ongoing developments in laser-driven ion acceleration [23][24][25]. A credible source of fast neutrons can also be obtained by deploying MeV electron jets from laser-driven exploding foils [5].…”

Nanometer-scale characterization of laser-driven compression, shocks, and phase transitions, by x-ray scattering using free electron lasers

“…We can use Eqn. (9) and calculate the dent depth. From the bow-tie half opening angle of approximately it follows that the depth would be approximately m which for the 72 ps delay between UHI laser irradiation and X-ray arrival translates into an average surface velocity of c. It is worth noting that since the laser intensity was barely relativistic, this surface recession is possibly not dominated by laser hole-boring but rather might be due to thermal expansion and ablation effects.…”

“…Research in laser-driven HED science is developing rapidly and is making contributions in a variety of areas ranging from plasma astrophysics [4] and fusion energy [5], to compact particle acceleration [6]- [9], short wavelength radiation generation [10], materials dynamics [11] and the exploration of new phases of matter [12]. Laser-driven HED plasmas and materials driven to high pressures are very complicated physical systems, characterized by a wide range of simultaneously occurring fundamental processes, many of which involve states far from equilibrium.…”

Accelerating ions with high-energy short laser pulses from submicrometer thick targets

“…We also discuss our recent experimental observation of maximum proton energies in excess of 85 MeV by laser-driven ion acceleration via the TNSA mechanism [11] .…”