3D printed imaging apertures for MicroPattern gas detector based full field of view X-ray fluorescence spectrometers

Abstract

Additive Manufacturing, commonly referred as 3D printing, opened a new way to promptly produce cost-effective imaging apertures based on high-density materials, to be used in x-ray imaging systems, such as MicroPattern Gas Detector (MPGD) based Full Field X-ray Fluorescence (FF-XRF) spectrometers. These provide energy and spatially resolved information, allowing the mapping of large area samples. Traditionally, image formation is accomplished with pinhole apertures, devices of easy manufacturing that lead to sub-micrometre position resolution values. However, the sensitivity of the imaging system is severely hampered. To surpass this issue, alternative optical components, such as parallel multi-hole collimators, can be used.In this work, 3D printed multi-hole collimators with different geometries and material compositions are presented and applied to a FF-XRF spectrometer based on the 2D-THCOBRA gas detector. The system's performance parameters with different collimators, namely, relative sensitivity and position resolution, were experimentally determined and compared with the ones obtained with pinhole-based setups. The FF-XRF spectrometer was also simulated, to understand how different collimator geometries affect sensitivity and position resolution.