Optically Stimulated Nanodosimeters with High Storage Capacity
David Van der Heggen,
Daniel R. Cooper,
Madeleine Tesson,
Jonas J. Joos,
Jan Seuntjens,
John A. Capobianco,
Philippe F. Smet
Affiliations
David Van der Heggen
LumiLab, Department of Solid State Sciences, Ghent University, Krijgslaan 281-S1, 9000 Gent, Belgium
Daniel R. Cooper
Medical Physics Unit, McGill University, Cedars Cancer Centre, 1001 Décarie Blvd, Montreal, QC H4A 3J1, Canada
Madeleine Tesson
Department of Chemistry and Biochemistry and Centre for NanoScience Research, Concordia University, 7141 Sherbrooke St. W., Montreal, QC H4B 1R6, Canada
Jonas J. Joos
LumiLab, Department of Solid State Sciences, Ghent University, Krijgslaan 281-S1, 9000 Gent, Belgium
Jan Seuntjens
Medical Physics Unit, McGill University, Cedars Cancer Centre, 1001 Décarie Blvd, Montreal, QC H4A 3J1, Canada
John A. Capobianco
Department of Chemistry and Biochemistry and Centre for NanoScience Research, Concordia University, 7141 Sherbrooke St. W., Montreal, QC H4B 1R6, Canada
Philippe F. Smet
LumiLab, Department of Solid State Sciences, Ghent University, Krijgslaan 281-S1, 9000 Gent, Belgium
In this work we report on the thermoluminescence (TL) and optically stimulated luminescence (OSL) properties of β-Na(Gd,Lu)F4:Tb3+ nanophosphors prepared via a standard high-temperature coprecipitation route. Irradiating this phosphor with X-rays not only produces radioluminescence but also leads to a bright green afterglow that is detectable up to hours after excitation has stopped. The storage capacity of the phosphor was found to be (2.83 ± 0.05) × 1016 photons/gram, which is extraordinarily high for nano-sized particles and comparable to the benchmark bulk phosphor SrAl2O4:Eu2+,Dy3+. By combining TL with OSL, we show that the relatively shallow traps, which dominate the TL glow curves and are responsible for the bright afterglow, can also be emptied optically using 808 or 980 nm infrared light while the deeper traps can only be emptied thermally. This OSL at therapeutically relevant radiation doses is of high interest to the medical dosimetry community, and is demonstrated here in uniform, solution-processable nanocrystals.
