Preliminary study on the thermoluminescence properties of CaF2 and Tm2O3 pellets

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2020-04, Vol.959, p.163561, Article 163561
• Main Authors: Rodríguez, R., Correcher, V., Gómez-Ros, J.M., Plaza, J.L.
• Format: Article
• Language: English
• Subjects: Calcium fluoride; Dry thermal preparation; Quenching of luminescence; Radiation Dosimetry; Thermoluminescence; Thulium oxide
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2020.163561

This contribution describes a dry physical process to increase luminescence of a mixture of calcium fluoride (CaF2) and thulium oxide (Tm2O3) pellets. Thermoluminescence (TL) technique has been used by means of two different filters (UV-blue and green) for the prepared aliquots irradiated with a  90Sr beta source (10 mGy/s). Many trapping centers were created during the preparation due to new structural defects in the CaF2 matrix, exhibiting a second maximum at 195 °C in the TL glow curve, and having fading of 11% after 1-month storage. Regarding the glow curve structure, first-order kinetics has been reported with a peak-I, around 130 °C, with an activation energy of 1.27(1) eV obtained by the initial rise method using a heating rate of 5 °C/s. Linearity property has been confirmed in the range from 0.1 Gy up to 2.0 Gy. UV-blue TL glow curve shown some changes when a lower heating rate (2 °C/s) was used. Peaks with greater intensity in a factor about 5%, and peaks position at lower temperatures (around 115 °C and 180 °C) were obtained. The results show that this low-cost phosphor can be used at doses higher than 10 mGy, such as in medical and industrial applications. The preparation process parameters used to produce this material are provided. •This work shows the simple preparation of a phosphor consisted on a mixture of CaF2 with Tm2O3 using a dry physical process.•The most intense maxima of the GCs have been found by Green TL (420–580 nm), while UV-Blue TL (300–460 nm) has partially displayed the light emission.•Linear dose response was demonstrated from 0.1 Gy up to 2.0 Gy.•Fading of 11% was obtained after 1-month storage.