The X‑ray Technologies Group at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) has more than three decades of experience in developing X‑ray based technologies for real time monitoring of elements and minerals in the mining and resources sector. A key component of this work is fundamental research that underpins advances in X‑ray imaging, spectroscopy and diffraction.
This paper presents the development and validation of a detailed GEANT4‑based Monte Carlo simulation framework for modelling the overall X‑ray emission spectra of both transmission and reflection X‑ray tubes. Representative tube geometries were implemented and two physics models, Penelope and Livermore, were evaluated. Simulated spectra were compared against experimental measurements, and we discuss the model that provides the most accurate description, the origin of previously reported discrepancies [1] and how these were resolved in the current work.
To expand the usefulness of the model, we also assessed the angular dependence of simulated tube output and validated it against measurements from multiple commercial X‑ray tubes. These included both reflection and transmission designs with different anode materials and from different manufacturers. This is particularly valuable for the development of new X‑ray imaging and X‑ray diffraction technologies. Our results demonstrate not only the performance of GEANT4 in modelling X‑ray sources, but also how detailed simulation can reveal measurable differences between tube designs from different manufacturers.
Accurate knowledge of X‑ray tube emission is essential for quantitative spectroscopy, experiment interpretation and the design and optimisation of new analytical technologies. The validated framework presented here provides a robust building block for these tasks and supports the development of next generation X‑ray systems.
[1] M. Kirkpatrick, S. Hood, S. Guatelli, Y. Van Haarlem, Radiation Physics and Chemistry, Volume 220, 2024, 111647.