Enhancing laser-driven proton acceleration by using micro-pillar arrays at high drive energy

Area of Science:

• Plasma Physics
• Laser-Matter Interaction
• Particle Acceleration

Background:

• High-power laser interactions with micro- and nano-structured surfaces are crucial for efficient energy absorption.
• Laser-driven ion acceleration holds promise for various applications, but efficiency remains a challenge.

Purpose of the Study:

• To investigate the use of vertically aligned metallic micro-pillar arrays for laser-driven proton acceleration.
• To enhance laser energy conversion efficiency and particle acceleration using structured targets.

Main Methods:

• Experimental irradiation of metallic micro-pillar arrays with high-energy-class laser pulses (intensities ~10^17-18 W/cm^2).
• Comparison of micro-pillar targets with standard planar targets.
• Two-dimensional particle-in-cell simulations to support experimental findings.

Main Results:

• Micro-pillar targets demonstrated significantly enhanced hot-electron production compared to planar targets.
• Strongly enhanced proton acceleration in terms of maximum energies and particle numbers was observed.
• Simulations confirmed increased laser energy conversion into hot electrons and stronger acceleration fields.

Conclusions:

• Vertically aligned metallic micro-pillar arrays are effective for improving laser-driven proton acceleration.
• Structured targets offer a viable strategy for enhancing laser-driven ion acceleration systems.
• This research opens avenues for optimizing future laser-driven ion acceleration technologies.