Development of CaSO4:RE,Li (RE = Tm, Eu, Tb) composites for thermally or optically stimulated luminescence dosimetry

Author(s)

Junot, Danilo O. ; Galeano, Diego C. ; Silva, Anderson M. B. ; Souza, Divanizia N. ; Caldas, Linda V. E.

• Document type: Journal article
• Source: Radiation Measurements; v. 176, p. 8-pg., 2024-06-24.

Abstract

This work proposed the development of CaSO4:Tm,Li, CaSO4:Tb,Li and CaSO4:Eu,Li composites for application in radiation dosimetry, using luminescent techniques such as thermoluminescence (TL) and optically stimulated luminescence (OSL). The CaSO4 crystals were produced by the adapted slow evaporation route and characterized using X-ray diffraction (XRD), TL and OSL techniques. XRD analyses showed that the doped CaSO4 samples presented a single phase. The CaSO4:Eu,Li composites showed TL signals with peaks around 145 degrees C and 180 degrees C. The CaSO4:Tb,Li and CaSO4:Tm,Li composites showed TL signals with peaks centered at 165 degrees C and 275 degrees C. For the CaSO4:Tb and CaSO4:Tm samples, the addition of lithium as co-dopant resulted into a significant increase (2x) in the total TL signal of the samples. The CaSO4:Tm,Li samples presented a very intense OSL signal, about 80x greater than the signal of the other samples produced. This allows the applicability of TL/OSL detectors even more sensitives. The TL emission spectra of the samples showed typical emissions of Eu2+ ions (280 nm), Eu3+ (614 nm), Tb3+ (544 nm) and Tm3+ (455 nm). No emission corresponding to lithium was identified. All the samples produced showed linearity in the dose range used and good reproducibility, with variations below 10%. The CaSO4:Tm,Li samples showed the lowest limit of detection and fading. The evaluated dosimetric characteristics denote that these developed composites have potential application as TL/OSL detectors. (AU)

• FAPESP's process: 18/05982-0 - R&D&I in radiation metrology in the health area
• Grantee: Linda Viola Ehlin Caldas
• Support Opportunities: Research Projects - Thematic Grants