Diagnosing the impact of relativistically intense prepulse on few-picosecond timeframes for short scale length laser-matter interactions

TL;DR

This paper investigates how intense prepulses affect the plasma conditions on ultra-thin targets in high-energy laser interactions, providing experimental benchmarks for future multi-petawatt laser systems.

Contribution

It combines experimental diagnostics and simulations to analyze prepulse effects on plasma scale length, offering new benchmarks for laser contrast control in ultra-intense laser experiments.

Findings

Intense prepulses cause rapid preplasma formation on nanofoil targets.

Laser contrast on few-ps timescales critically influences laser-matter interaction conditions.

Experimental benchmarks for laser contrast are established for future high-energy laser facilities.

Abstract

With the rapid proliferation of multi-petawatt (MPW) lasers globally, a new era of high-energy density science promises to emerge within the next decade. However, precise control over how light at these ultra-relativistic intensities interacts with matter (especially with solid-density targets) will be crucial to fully realize the cutting-edge scientific advancements and technological breakthroughs that the MPW regime promises to unlock. In this manuscript, we present experimental results, supported by numerical simulations, which show how intense prepulse activity on few-ps ($10^{-12}$ s) timescales leads to rapid shifts in the steepness of the preplasma generated on the surface of ultra-thin nanofoil targets. By combining a single-shot frequency resolved optical gating (FROG) autocorrelation device to diagnose on-shot incident laser pulse contrast, with coherent synchrotron emission (CSE) from relativistic laser plasmas as a probe for evolving plasma-scale length conditions, we provide an experimental benchmark for laser contrast on forthcoming MPW facilities, where high contrast on few-ps timescales will be essential for the next generation of laser-solid interactions.