High-resolution X-ray imaging with samarium-doped fluoroaluminate and fluorophosphate glass

• Published in: Journal of non-crystalline solids Vol. 377; pp. 124 - 128
• Main Authors: Edgar, A., Varoy, C.R., Koughia, C., Okada, G., Belev, G., Kasap, S.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier B.V 01-10-2013; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Dosimetry; Exact sciences and technology; Fluoroaluminate glass; Fluorophosphate glass; Glasses (including metallic glasses); Magnetic properties and materials; Magnetic recording materials; Materials science; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics; Samarium-doped glass; Specific materials; Studies of specific magnetic materials; Valence conversion; Dosimetry; Valence conversion; Fluorophosphate glass; Fluoroaluminate glass; Samarium-doped glass; Phosphates; Filtration; Transfer functions; Photoluminescence; Glass; X-ray imaging; Europium additions; Valence; Samarium additions; Acceptor center; Modulation; Cerium additions; Recording material; Donor center; Codoping
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2012.12.022

We report the use of samarium-doped (Sm3+) fluoroaluminate and fluorophosphate glasses for X-ray imaging. Incident X-rays convert samarium ions from the trivalent to the divalent state on a semi-permanent but erasable basis. Of the three fluorophosphate glass compositions investigated, that with the smallest fraction of phosphate bonds showed the greatest conversion, but fluoroaluminate glass showed better conversion than any of them. The effects of polyvalent co-dopants Ce, Eu, Pb, Sn, and In, (which may potentially act as electron donors or acceptors) on the conversion efficiency were investigated in fluoroaluminate glass, and whilst In and Sn inhibit the conversion, none of the co-dopants produced significant enhancement. The valence conversion may be used for X-ray imaging through the photoluminescence of the X-ray generated Sm2+ ions. With an optimal choice of the excitation wavelength and appropriate optical filtration in the camera-based recording system, very high-resolution X-ray imaging can be achieved. Recorded images show resolved detail down to the level of 25μm, and the measured modulation transfer function extends out to 11line pairs/mm.
► Substantial radiation-induced valence change of samarium ► Photoluminescence of Sm2+ as a basis for X-ray imaging ► Very high resolution X-ray imaging achieved to 25μm scale ► Thermal enhancement and erasability of conversion