Inelastic electron injection in a water chain

TL;DR

This paper introduces a real-time method to simulate inelastic electron-phonon interactions in a water chain, revealing how vibrational temperature influences electron injection and propagation relevant to biological damage.

Contribution

A novel simulation approach capturing inelastic electron-phonon energy exchange dynamics in a biological water model.

Findings

Electrons near excited state bands can enter the water chain via phonon interactions.

Electron injection and movement are highly sensitive to vibrational temperature.

The method enables real-time analysis of inelastic electron dynamics in biological environments.

Abstract

Irradiation of biological matter triggers a cascade of secondary particles that interact with their surroundings, resulting in damage. Low-energy electrons are one of the main secondary species and electron-phonon interaction plays a fundamental role in their dynamics. We have developed a method to capture the electron-phonon inelastic energy exchange in real time and have used it to inject electrons into a simple system that models a biological environment, a water chain. We simulated both an incoming electron pulse and a steady stream of electrons and found that electrons with energies just outside bands of excited molecular states can enter the chain through phonon emission or absorption. Furthermore, this phonon-assisted dynamical behaviour shows great sensitivity to the vibrational temperature, highlighting a crucial controlling factor for the injection and propagation of electrons in water.