  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.
