Integrating the detector mask into the detector itself
Most of our phase-based imaging methods use two masks, placed before imaged sample and detector respectively, to make an x-ray imaging system sensitive to refraction and ultra-small angle scattering. By working with Prosperity Partnership’s external partner Scintacor/Photonic Science, we have demonstrated that the second (detector) mask can be integrated directly into the detector itself, which simplifies setup complexity and alignment procedures. We did this by replacing the standard scintillator of an indirect conversion detector with a “structured” one, where trenches filled with scintillating material replace the apertures in the detector mask. The remainder of the detector area remains insensitive to x-rays, equivalently to the absorbing septa of the same mask. We have shown that use of this “structured” scintillator provides similar results to our standard double-mask configuration, and it allows a reliable retrieval of phase and attenuation.
Attenuation (far left) and differential phase (centre) of small wires quantitatively retrieved using a detector equipped with a structured scintillator replacing the absorbing mask normally placed before the detector itself. The image on the far right (also obtained with the structured detector) shows how the latter channel allows the visualisation of thin cartilage layers, invisible to conventional x-rays.