[21a-P07-1~30] 2 Ionizing Radiation(Poster)

▲ [21a-P07-25] Optical and scintillation properties of Tm-doped La₂Si₂O₇ crystal

〇(D)Prom Kantuptim¹, Daisuke Nakauchi¹, Takumi Kato¹, Noriaki Kawaguchi¹, Takayuki Yanagida¹ (1.NAIST)

Keywords:scintillator, Tm3+, lanthanum pyrosilicate

Ionizing radiation such as X-ray and γ-ray has been using widely in many fields of expertise. To measuring the ionizing radiation, the Ionizing radiation is needed to convert to the lower-energy photon that detectable by a photodetector. The materials category that has this conversion ability is called scintillator. Single crystalline scintillators are doped with rare-earth ions as a luminescence center have been commonly investigated. As such an emission center ion, Tm³⁺ is well known for clear visible light emission in the blue range which is necessary for the display and other blue phosphors-related devices. Also, Our previous study on the Tm-doped La₂Si₂O₇ (Tm:LPS) presents decent scintillation properties such as scintillation light yield at 2340 ph/MeV, low afterglow, and good liner relationship between γ-ray energy and photoabsorption peak channel. At this point, the substitutional of Lu by La in the host material is promising to have interesting results.
In this study, we focused on the optical and scintillation properties of Tm-doped La₂Si₂O₇ (Tm:LaPS) single crystals synthesized by the floating zone method. Then, we evaluated the photoluminescence (PL) and scintillation properties such as emission spectra, decay time, and pulse height measurement.In the X-ray-induced scintillation spectra of the undoped and 0.1-5.0 % Tm-doped LPS crystal, Several sharp peaks appeared at 350 nm and 450 nm due to the Tm³⁺ 4f-4f transitions (¹D₂→³H₆ and ¹D₂→³F₄)_, respectively. In the PL emission map, Unlike the scintillation spectra, Tm:LaPS sample only exhibits the emissions at 450 nm (¹D₂→³F₄). The PL quantum yield of the Tm:LaPS sample is observed at 22.0 %.