Li₂B₄O₇:Dy,Na Thermoluminescent Phosphor Synthesized By Combustion Method for out‑of‑Field Dose Estimation In Advanced Radiotherapy
Abstract
Purpose
Li₂B₄O₇:Dy,Na Thermoluminescent Phosphor Synthesized by Combustion Method for Out‑of‑Field Dose Estimation in Advanced Radiotherapy
Methods
Li₂B₄O₇:Dy,Na powders were prepared via solution combustion using lithium nitrate, sodium nitrate, boric acid, urea, and sodium nitrate–based fuel–oxidizer mixtures, with Dy and Na dopant concentrations varied between 0.1–1.0 mol% for optimization. Structural properties were examined by X‑ray diffraction to confirm phase purity, while TL measurements were performed after photon irradiation to evaluate glow‑curve shape, dose–response behavior, and thermal stability over a wide dose range relevant to out‑of‑field regions.
Results
X‑ray diffraction confirmed formation of a crystalline Li₂B₄O₇ phase suitable for dosimetric use. The co‑doped phosphor exhibited a dominant, well‑resolved glow peak in the 150–250 °C region, with TL intensity increasing nearly linearly from cGy to high‑dose levels and showing minimal supralinearity at higher doses. The material demonstrated good signal reproducibility and low fading over the post‑irradiation storage period studied, indicating robust trap stability
Conclusion
Li₂B₄O₇:Dy,Na synthesized by combustion exhibits stable glow‑curve characteristics, a wide quasi‑linear dose–response, and favorable fading behavior, making it a promising candidate TL dosimeter for low‑level out‑of‑field dose assessment in advanced radiotherapy techniques such as IMRT and VMAT