Saturday 15 March 2025
For years, scientists have struggled to accurately simulate the behavior of low-energy gamma rays as they pass through different materials. This is a crucial problem in fields such as medical physics and radiation detection, where precise calculations are essential for understanding the effects of ionizing radiation on living tissues.
Now, researchers at the Universidad Complutense de Madrid in Spain have made significant progress towards solving this challenge. They’ve developed an updated version of their LegPy software package, which simulates the passage of low-energy gamma rays through materials by taking into account a previously neglected process: X-ray fluorescence.
X-ray fluorescence occurs when a high-energy photon is absorbed by an atom, causing it to emit a lower-energy X-ray photon. This process can have a significant impact on the behavior of low-energy gamma rays, particularly in heavy materials such as lead and bone.
To simulate this process accurately, the researchers used a simple model that takes into account the probability of photoelectric absorption and the fluorescence yield for different elements. They also assumed that the relative probability of photoelectric interaction in each atom is proportional to its atomic number.
The results are impressive: when compared to established codes such as PENELOPE, the updated version of LegPy produces accurate simulations of dose buildup in heavy materials such as lead and bone. In one example, the researchers found that neglecting X-ray fluorescence led to a significant overestimation of the dose in lead at depths greater than 5 millimeters.
The implications of this work are far-reaching. For medical physicists, it means they can now simulate the behavior of low-energy gamma rays with greater accuracy, which is essential for understanding the effects of radiation therapy on cancer patients. For researchers working on radiation detection and imaging systems, it means they can design more accurate detectors and imagers that can better detect and image sources of ionizing radiation.
The updated version of LegPy has also been tested in simulations of scintillators such as sodium iodide and bismuth germanium oxide. These materials are commonly used in radiation detection and imaging systems, and the researchers found that the updated code accurately simulates the spectra of absorbed energy in these materials.
Overall, this work represents an important step forward in our understanding of low-energy gamma ray behavior and its implications for a range of applications. By incorporating X-ray fluorescence into their simulations, scientists can now make more accurate predictions about the behavior of ionizing radiation in different materials, which will ultimately lead to better designs and more effective technologies.
Cite this article: “Accurate Simulations of Low-Energy Gamma Rays through Materials”, The Science Archive, 2025.
Gamma Rays, Low-Energy, Radiation Detection, Medical Physics, X-Ray Fluorescence, Legpy Software, Simulation, Ionizing Radiation, Radiation Therapy, Scintillators
Reference: Victor Moya, Jaime Rosado, Fernando Arqueros, “Implementation of X-rays production in LegPy” (2025).
