Comparative study of scintillation and dosimetric properties between Tm-doped CaF₂translucent ceramic and single crystal

Abstract

We fabricated a Tm-doped CaF2 translucent ceramic by spark plasma sintering (SPS), and evaluated its photoluminescence (PL), scintillation, and dosimetric properties compared with those of a single crystal. Both the samples exhibited emission peaks originating from the 4f–4f transitions of Tm3+ under visible-light and X-ray irradiation. The intensities of PL and scintillation for the single crystal were higher than those for the translucent ceramic. Regarding thermally stimulated luminescence (TSL), both the samples showed main glow peaks at approximately 145 and 265 °C. The Tm-doped translucent ceramic exhibited a higher TSL sensitivity than did the single crystal and showed a linear response against X-ray dose over the dose range from 0.01 to 1000 mGy.

Optical and Scintillation Properties of YAlO3 Doped with Rare-Earths Emitting Near-infrared Photons

“…(32,33) The 1% Tm 3+ -doped sample indicated strong emissions of around 450 nm ( 1 D 2 → 3 F 4 ) and 800 nm ( 3 H 4 → 3 H 6 ). (34,35) Here, QY values of all the samples were calculated by the integration of signal intensity in the range from 200 to 700 nm and 700 to 950 nm in order to divide the UV-VIS emission from the NIR emission, and the obtained results are summarized in Table 1. Among all the samples, the 1% Pr 3+ -doped sample showed the highest QY in the UV-VIS range, and the 1% Tm 3+ -doped sample showed the highest QY in the NIR range.…”

Evaluation of Optically Stimulated Luminescence Properties of Tm-doped NaMgF3 Single Crystal

“…These peaks were attributed to the 1 I 6 -3 F 4 , 1 D 2 -3 H 6 , 1 D 2 -3 F 4 , 1 G 4 -3 H 6 , 1 D 2 -3 H 5 , and 1 D 2 -3 H 4 transitions of Tm 3+ . (24,27) On the other hand, the undoped sample exhibited a broad emission peak from 300 to 550 nm. This emission peak is considered to be due to self-trapped excitons (STEs) and some types of defect.…”

“…(28) In the Tm-doped sample, the primary decay time constant was attributed to the 4f-4f ( 1 G 4 -3 H 6 ) transitions of Tm 3+ . (24) The secondary decay constant could not be attributed explicitly to any factor because the typical decay time constant of the 4f-4f transitions of Tm 3+ was less than 300 µs. (27,30,31) However, some fluoride materials showed similar components in X-ray-induced scintillation decay time profiles.…”

“…(27,30,31) However, some fluoride materials showed similar components in X-ray-induced scintillation decay time profiles. (24,32) Figure 5 shows the OSL spectrum of the Tm-doped sample. The OSL peak was observed at around 360 nm upon 470 nm stimulation, and the peak position was consistent with the X-rayinduced scintillation spectrum of the Tm-doped sample.…”

“…As an activator, we focused on Tm since Tm is a candidate dopant for generating luminescence centers, and dosimetric properties were reported in some Tm-doped materials. (23,24) In this study, we synthesized undoped and Tm-doped NaMgF 3 single crystals and investigated their OSL properties. In addition to OSL properties, scintillation properties were also investigated to identify the origin of luminescence.…”