A team of researchers has successfully developed 3D printed multi-hole collimators for X-ray imaging systems, offering a cost-effective alternative to traditional pinhole apertures. This development has the potential to enhance the sensitivity and position resolution of X-ray fluorescence (XRF) spectrometers, paving the way for more accurate and detailed analyses.
The study, published in Spectrochimica Acta Part B: Atomic Spectroscopy, explored the performance of multi-hole collimators with varying geometries and material compositions in a full-field XRF spectrometer based on the 2D-THCOBRA gas detector (a special micropattern gaseous detector [MPGD] design). The researchers evaluated the relative sensitivity and position resolution of different setups, comparing them to pinhole-based configurations (1).
Their findings revealed that the use of smaller pinholes, while limiting system sensitivity, provides superior position resolution. Conversely, collimators with large holes and small septa yielded higher sensitivity but compromised position resolution. The best position resolution, 1.10 ± 0.02 mm full width at half maximum (FWHM), was achieved with a 0.3 mm diameter pinhole aperture, which also exhibited the lowest relative sensitivity. The lead (Pb) collimator with 2 mm hexagonal holes presented the worst position resolution value, 3.25 ± 0.09 mm FWHM (1).
In terms of sensitivity, the low attenuation coefficient and small depth of the copper (Cu) collimator with 1 mm circular holes resulted in the highest sensitivity–50 times greater than the value achieved with the smaller pinhole aperture.
These findings underscore the critical trade-off between sensitivity and position resolution in XRF imaging, emphasizing the importance of tailoring the optical component to the specific application. While pinhole apertures allow magnification for enhanced detail, they may compromise sensitivity. Multi-pinhole collimators, as used in SPECT imaging of small animals, offer a balance between sensitivity and position resolution.
The researchers highlight the potential of 3D printed collimators as a cost-effective and versatile solution for energy dispersive X-ray fluorescence (EDXRF) system applications. 3D printing enables the exploration of diverse geometries and designs, paving the way for further advancements in XRF imaging technology.
This research holds significant implications for various fields, including environmental monitoring, material analysis, and biomedical imaging. The development of 3D printed multi-hole collimators promises to enable more accurate, sensitive, and versatile analyses.
Carvalho, P. M. S.; Leite, F. D.; Tavares, G.; Correia, P. M. M.; Oliveira, J. M. M.; Veloso, J. F. C. A.; Silva, A. L. M. 3D Printed Imaging Apertures for MicroPattern Gas Detector Based Full Field of View X-Ray Fluorescence Spectrometers. Spectrochim. Acta Part B: Atomic Spectrosc. 2023, 210, 106806. DOI: 10.1016/j.sab.2023.106806.