Laser ion acceleration by a near-critical density target

Abstract

Protons having energies up to 3.8 MeV are experimentally generated by the p-polarized, 45 fs, ∼ 10 19 W/cm 2 laser pulse interacting with a near-critical plasma cloud produced by the irradiation of the amplified spontaneous emission (ASE) pedestal at an intensity of ∼ 10 13 W/cm 2 onto a 7.5-µm-thick polyimide foil target. The emission angle of the high-energy protons is shifted away from the target normal toward the laser-propagation direction of 45 • . The mechanism which explains the proton generation from the near-critical plasma cloud is discussed using the twodimensional (2D) particle-in-cell (PIC) simulation.

Proton acceleration to 40 MeV using a high intensity, high contrast optical parametric chirped-pulse amplification/Ti:sapphire hybrid laser system

“…Nearly absent (a few percent) specular reflection at 10 20 W∕ cm 2 indicates a substantial absorption of the main pulse in a fewmicrometers plasma created by the pedestal at the target surface. For less dense targets, the proton beam deflection is also caused by a quasi-static magnetic field created by the main laser pulse [21], whereas for denser and thinner targets it is due to relativistic effects at oblique incidence [22].…”

Laser ion acceleration using a solid target coupled with a low-density layer

“…Some recent experiments aimed at improving ion acceleration by laser pulses have considered solid targets of thickness short enough that the long laser prepulse produces a near-critical plasma [9], or even ultrashort thickness such that the expansion during the interaction leads to self-induced transparency, i.e. to an overdense to underdense transition [10,11] [8] regimes.…”

Strongly Coupled Nonequilibrium Nanoplasma Generated by a Fast Single Ion in Solids

“…[1][2][3][4]). Due to absorption features of ion beams, they are widely used for a number of important technical [5,6] and medical [7,8] applications. The interaction of a single fast heavy ion with condensed matter leads to the formation of a track.…”