Design of plasma shutters for improved heavy ion acceleration by ultra-intense laser pulses

TL;DR

This paper explores how plasma shutters can enhance heavy ion acceleration by increasing ion energy and focusing ion beams, using simulations and proposing a design for double plasma shutters to optimize laser pulse shaping.

Contribution

It introduces a novel approach to using plasma shutters for improving heavy ion acceleration, including simulation results and a prototype design for double plasma shutters.

Findings

Maximal high-Z ion energy increases with plasma shutters.

Ion beams are more focused and have lower divergence with shutters.

Double plasma shutters can withstand and shape high-intensity laser pulses.

Abstract

In this work, we investigate the application of the plasma shutters for heavy ion acceleration driven by a high-intensity laser pulse. We use particle-in-cell (PIC) and hydrodynamic simulations. The laser pulse, transmitted through the opaque shutter, gains a steep-rising front and its peak intensity is locally increased at the cost of losing part of its energy. These effects have a direct influence on subsequent ion acceleration from the ultrathin target behind the shutter. In our 3D simulations of silicon nitride plasma shutter and a silver target, the maximal energy of high-Z ions increases significantly when the shutter is included for both linearly and circularly polarized laser pulses. Moreover, application of the plasma shutter for linearly polarized pulse results in focusing of ions towards the laser axis in the plane perpendicular to the laser polarization. The generated high energy ion beam has significantly lower divergence compared to the broad ion cloud, generated without the shutter. The effects of prepulses are also investigated assuming a double plasma shutter. The first shutter can withstand the assumed sub-ns prepulse (treatment of ns and ps prepulses by other techniques is assumed) and the pulse shaping occursvia interaction with the second shutter. On the basis of our theoretical findings, we formulated an approach towards designing a double plasma shutter for high-intensity and high-power laser pulses and built a prototype.