Development of X-ray-induced afterglow characterization system

We have synthesized undoped and rare-earth (RE)-doped 12CaO·7Al 2 O 3 (RE:C12A7) crystals by the floating zone (FZ) method to systematically study the effects of RE doping (doped with all the lanthanoid elements except for Sc, Y, La, Pm, and Lu) in C12A7 for radiation detector applications. In both photoluminescence (PL) and scintillation, the undoped C12A7 crystal showed a weak emission due to the lattice defects appearing at around 500 nm, and the decay time was on the order of several nanoseconds. On the other hand, the RE:C12A7 crystals showed PL and scintillation owing to the 4f-4f transitions of RE 3+ ions appearing from the UV to NIR ranges depending on the RE element. The decay times of these emissions ranged from a few microseconds to milliseconds depending on the RE element and the values were typical for the electronic transitions of trivalent rare earths.

Section: Methodsmentioning

confidence: 99%

Optical and Scintillation Properties of Rare-Earth Ion-Doped 12CaO·7Al2O3 Single Crystals

2017

“…Figure 7 shows the scintillation decay time profiles of SNGS and LTGA. In our previous study, (2) we could not measure the decay time profile of LTGA but, owing to the development of the new characterization system, (17) we could observe it in this study. The scintillation decay time of LTGA was 8 ns, which is similar to that in PL decay.…”

Section: Resultsmentioning

confidence: 99%

“…The emission was measured using an Andor DU-420-BU2 CCD spectrometer, and a detailed explanation for the setup was previously reported. (15) X-ray-induced decay time kinetics were evaluated using a pulse X-ray streak system (16) to observe the rise part and an afterglow characterization system with the fast mode (17) for the entire decay time profile. Finally, scintillators were coupled with photomultiplier tube (PMT) R7600-200 (Hamamatsu) with optical grease, and a 137 Cs γ-ray or 241 Am α-ray were irradiated.…”

Section: Methodsmentioning

confidence: 99%

Comparative Study of Optical and Scintillation Responses of Sr3NbGa3Si2O14 (SNGS) and La3Ta0.5Ga5.3Al0.2O14 (LTGA) Crystals

2015

Optical and scintillation properties of Sr 3 NbGa 3 Si 2 O 14 (SNGS) single crystal were evaluated for the first time and compared with those of La 3 Ta 0.5 Ga 5.3 Al 0.2 O 14 (LTGA), which was previously reported to exhibit such properties. SNGS showed ~80% optical transmittance at wavelengths longer than 250 nm. Under 250 nm excitation, a strong photoluminescence (PL) appeared at 400 nm with a primary decay time of 1.4 ns. In an X-ray-induced radioluminescence spectrum, an intense emission peak at 400 nm was observed, and the primary scintillation decay time was ~1.37 μs. Finally, the absolute scintillation light yield of SNGS turned out to be 850 photons/MeV, which was higher than that of LTGA.

“…(26) The scintillation decay time profile was obtained using a customized-setup, pulsed X-rayinduced scintillation characterization system (Hamamatsu). (27) Pulsed X-rays were generated by combining the pulsed LED light source and X-ray tube. The scintillation light was measured with a Hamamatsu R7400P-06 photomultiplier tube (PMT).…”

Section: Methodsmentioning

confidence: 99%

Characterizations of CsSrCl3:Ce Crystalline Scintillator

2017

We report on the photoluminescence and scintillation characterizations of a new CsSrCl 3 :Ce (0.5 mol%) crystalline scintillator grown by the vertical Bridgman method. The fluorescence quantum efficiency (QE) for the Ce 3+ 5d-4f allowed transitions at around 365-425 nm was 90%under excitation of 315 nm light. The photoluminescence decay time of Ce 3+ was approximately 28 ns. When X-rays excited the crystal, intense emission bands were observed at 350-400 nm, which could be attributed to the Ce 3+ characteristic emission. The scintillation light yield of the developed crystal was ~8600 photons/MeV compared with a NaI:Tl commercial scintillator, and the principal scintillation decay time was approximately 626 ns plus two fast components of around 3.8 and 57 ns.