Effects of oblique incidence and colliding pulses on laser-driven proton acceleration from relativistically transparent ultrathin targets

Abstract

The use of ultrathin solid foils offers optimal conditions for accelerating protons from laser-matter interactions. When the target is thin enough that relativistic self-induced transparency (RSIT) sets in, all of the target electrons get heated to high energies by the laser, which maximizes the accelerating electric field and therefore the final ion energy. In this work, we first investigate how ion acceleration by ultraintense femtosecond laser pulses in transparent CH${}_2$ solid foils is modified when turning from normal to oblique ($45^{\circ }$) incidence. Due to stronger electron heating, we find that higher proton energies can be obtained at oblique incidence but in thinner optimum targets. We then show that proton acceleration can be further improved by splitting the laser pulse into two half-pulses focused at opposite incidence angles. An increase by $\sim 30\%$ in the maximum proton energy and by a factor of $\sim 4$ in the high-energy proton charge is reported compared to the reference case of a single normally incident pulse.

arXiv comment11 pages, 7 figures

References in corpus (8)

• Ion acceleration by superintense laser-plasma interaction
• Radiation Pressure Dominate Regime of Relativistic Ion Acceleration
• Ion acceleration in multispecies targets driven by intense laser radiation pressure
• Laser Ion Acceleration Scaling Laws Seen in Muti-Parametric PIC Simulations
• Ion energy scaling under optimum conditions of laser plasma acceleration
• Kinetic and finite ion mass effects on the transition to relativistic self-induced transparency in laser-driven ion acceleration
• Radiation Pressure Driven Ion Weibel Instability and Collisionless Shocks
• Proton acceleration by a pair of successive ultraintense femtosecond laser pulses

Cited by in corpus (3)

• Synchrotron radiation from ultrahigh-intensity laser-plasma interactions and competition with Bremsstrahlung in thin foil targets
• Particle-in-Cell modeling of a potential demonstration experiment for double pulse enhanced target normal sheath acceleration
• Terahertz emission from submicron solid targets irradiated by ultraintense femtosecond laser pulses