Real-time Electron Solvation Induced by Bursts of Laser-accelerated Protons in Liquid Water

TL;DR

This study uses laser-driven proton bursts to observe ultra-fast electron solvation in liquid water, revealing a longer solvation time than current models predict, indicating a highly dynamic initial phase of proton interaction.

Contribution

It introduces a novel application of picosecond laser-driven proton bursts to directly measure electron solvation dynamics in water, highlighting discrepancies with existing models.

Findings

Proton-induced electron solvation time exceeds 20 ps compared to photolysis.

A highly dynamic phase occurs immediately after proton interaction.

Current models do not fully account for this rapid solvation process.

Abstract

Understanding the mechanisms of proton energy deposition in matter and subsequent damage formation is fundamental to radiation science. Here we exploit the picosecond (10^-12 s) resolution of laser-driven accelerators to track ultra-fast solvation dynamics for electrons due to proton radiolysis in liquid water (H2O). Comparing these results with modelling that assumes initial conditions similar to those found in photolysis reveals that solvation time due to protons is extended by > 20 ps. Supported by magneto-hydrodynamic theory this indicates a highly dynamic phase in the immediate aftermath of the proton interaction that is not accounted for in current models.