Danish Research Unveils Insights into Ionising Radiation Effects

Recent research conducted at the ASTRID2 synchrotron in Aarhus, Denmark, has provided new insights into the effects of ionising radiation on materials. This study emphasizes the significance of interatomic Coulombic decay (ICD) in understanding radiation damage processes, which are crucial in fields such as medical physics and materials testing.

Ionising radiation, including ultraviolet (UV) and X-ray radiation, interacts with solid matter, initiating a series of complex processes. The first step typically involves photoionisation, where an atom or molecule absorbs a photon and loses one or more electrons. Following this, the subsequent processes can vary widely depending on the radiation’s intensity and the characteristics of the material. One of the critical effects observed is the generation of secondary radiation, which can significantly influence the overall dynamics of the system.

Among these secondary effects, interatomic Coulombic decay has gained notable attention since its discovery. This phenomenon occurs when energy is transferred from one excited atom or molecule to a neighboring one, resulting in its ionisation. Importantly, ICD often produces low-energy electrons, which can contribute to radiation damage in biological tissues. The research team aimed to deepen the understanding of ICD through their latest experiments.

Utilizing the advanced capabilities of the ASTRID2 synchrotron, the researchers examined the interactions between extreme UV photons and small clusters of helium atoms. To capture the dynamics of these interactions, they employed an electron velocity-map imaging spectrometer. This diagnostic tool measures both the energy and angular distribution of emitted electrons, allowing for a comprehensive analysis of the processes at play.

The findings revealed that the ICD process is even more efficient than previously understood. This efficiency suggests that ICD could play a significant role in other condensed phase systems exposed to ionising radiation. The implications of this research are particularly important for areas such as radiation therapy, where precise control over the effects of ionising radiation on human cells is essential.

The study, titled “Interatomic Coulombic decay in lithium-doped large helium nanodroplets induced by photoelectron impact excitation,” is set to be published in the journal Reports on Progress in Physics in 2025, authored by Ben Ltaeif and colleagues. The insights gained from this research contribute to a better understanding of the mechanisms underlying radiation interactions, paving the way for advancements in both therapeutic applications and materials science.