Research Achievements - Original paper -

Evaluation of radiation response properties of Eu2O3–doped Bi2O3–ZnO–TeO2 glass and glass ceramics

S. Muneta, N. Kawano, D. Nakauchi, T. Kato, K. Okazaki, K. Ichiba, T. Kunikata, A. Nishikawa, K. Miyazaki, F. Kayaga, K. Shinozaki, T. Yanagida

Sensors and Materials   37 ( 2 ) 509 - 518   2025.02  [Refereed]

Research paper (journal)   Domestic Co-author

Scintillation and dosimeter properties of Tb-doped strontium fluoride transparent ceramics

N. Kawano, T. Kato, R.L. Conner, L.G. Jacobsohn, D. Nakauchi, K. Okazaki, K. Ichiba, Y. Takebuchi, T. Yanagida

Journal of Luminescence   276   120868   2024.12  [Refereed]

Research paper (journal)   International Co-author

Photoluminescence and scintillation characteristics of two-dimensional organic–inorganic perovskite-type compounds with an ether diamine,

T. Suto, N. Kawano, K. Okazaki, K. Ichiba, Y. Takebuchi, T. Kato, D. Nakauchi, T. Yanagida

Optical Materials   153   115551   2024.07  [Refereed]

Research paper (journal)   Domestic Co-author

Scintillation and dosimetric properties of Tb4O7-doped Ca2BO3Cl

N. Kawano, T. Kato, D. Nakauchi, H. Fukushima, Y. Takebuchi, D. Shiratori, T. Yanagida

Journal of Materials Science: Materials in Electronics   35   1396   2024.07  [Refereed]

Research paper (journal)   Domestic Co-author

Luminescence properties of Tb3+-activated K2O–La2O3–Ga2O3 glasses

N. Kawano, K. Shinozaki, D. Nakauchi, T. Kato, Y. Takebuchi, H. Fukushima. T. Yanagida

Optical Materials X   23   100344   2024.07  [Refereed]

Research paper (journal)   Domestic Co-author

Br-substituent effect on photoluminescence and scintillation properties of (C6H5C2H4NH3)2PbCl4 perovskite-type compounds

S. Matsuzawa, K. Okazaki, D. Nakauchi, N. Kawano, T. Suto, T. Kato, N. Kawaguchi, T. Yanagida

Journal of Luminescence   270   120547   2024.06  [Refereed]

Research paper (journal)   Domestic Co-author

Optical and scintillation properties of (C4H9NH3)2PbI4 and phenyl group-introduced (C6H5C4H8NH3)2PbI4 single crystals assembling quantum well structures

K. Okazaki, D. Nakauchi, N. Kawano, N, Kawaguchi, T. Yanagida

Optical Materials   149   115062   2024.04  [Refereed]

Research paper (journal)   Domestic Co-author

Optical and scintillation properties of (ClPEA)2PbCl4 crystals forming quantum well structures

S. Matsuzawa, K. Okazaki, D. Nakauchi, N. Kawano, T. Suto, T. Kato, N. Kawaguchi, T. Yanagida

Nucl. Instrum. Methods Phys. Res. B   549   165291   2024.04  [Refereed]

Research paper (journal)   Domestic Co-author

Radiation response properties of Ce-doped CaF2 transparent ceramics

N. Kawano, T. Kato, R.L. Conner, L.G. Jacobsohn, D. Nakauchi, Y. Takebuchi, H. Fukushima, D. Shiratori, T. Yanagida

Materials Research Bulletin   171 - 112609   2024.03  [Refereed]

Research paper (journal)   International Co-author

Dosimetric properties of Eu-doped Ca2BO3Cl

T. Wauke, N. Kawano, T. Kato, Y. Takebuchi, H. Fukushima, G. Okada, T. Yanagida

Nucl. Instrum. Methods Phys. Res. B   548   165227   2024.03  [Refereed]

Research paper (journal)   Domestic Co-author

Photoluminescence, scintillation, and TSL properties of Dy-doped BaCaBO3F

N. Kawano, H. Kimura, G. Okada, D. Nakauchi, T. Yanagida

Nucl. Instrum. Methods Phys. Res. B   547   165212   2024.02  [Refereed]

Research paper (journal)   Domestic Co-author

Effect of Ca-substitution on (C6H5C2H4NH3)2PbBr4 crystal scintillator

D. Nakauchi, N. Kawano, T. Kato, N. Kawaguchi, T. Yanagida

Optical Materials   148   114956   2024.02  [Refereed]

Research paper (journal)   Domestic Co-author

Fabrication of a robust organic–inorganic perovskite nanoparticle dispersion layer on a glass surface

K. Shinozaki, N. Kawano, A. Yamada, S. Ichikawa, T. Fujima

Ceramics Internaitonal   50 ( 9 ) 14113 - 14117   2024.02  [Refereed]

Research paper (journal)   Domestic Co-author

Scintillation properties of (Ph4P)2ZnX4 (X = Cl, Br)

T. Suto, N. Kawano, K. Okazaki, K. Ichiba, Y. Takebuchi, T. Kato, D. Nakauchi, T. Yanagida

Japanese Journal of applied physics   63   01SP17   2024.01  [Refereed]

Research paper (journal)   Domestic Co-author

Dosimetric properties of Tm2O3-doped Ca2BO3Cl

T. Wauke, N. Kawano, D. Nakauchi, T. Kato, H. Fukushima, Y. Takebuchi, T. Yagagida

Japanese Journal of applied physics   63   01SP10   2024.01  [Refereed]

Research paper (journal)   Domestic Co-author

Radiation response properties of organic－inorganic perovskite-type compounds in a nanoporous glass

N. Kawano, K. Shinozaki, D. Nakauchi, T. Kato, Y. Takebuchi, T. Yanagida

Japanese Journal of applied physics   63   01SP07   2024.01  [Refereed]

Research paper (journal)   Domestic Co-author

Optical and scintillation characteristics of organic–inorganic layered compounds with a linear alkyl diamine,

T. Suto, N. Kawano, K. Okazaki, K. Ichiba, Y. Takebuchi, T. Kato, D. Nakauchi, T. Yanagida

J. Mater. Sci: Mater. Electron   35   176   2024.01  [Refereed]

Research paper (journal)   Domestic Co-author

Preparation and scintillation properties of the Eu2O3-doped TeO2–Nb2O5–SrO glasses

S. Muneta, N. Kawano, D. Nakauchi, T. Kato, D. Shiratori, H. Fukushima, Y. Takebuchi, K. Shinozaki, T. Yanagida

Optical Materials   146   114574   2023.12  [Refereed]

Research paper (journal)   Domestic Co-author

Scintillation properties of Er3+-activated BaO–Nb2O5–TeO2 glasses

N. Kawano, K. Okazaki, Y. Takebuchi, H. Fukushima, T. Kato, D. Nakauchi, F. Kagaya, K. Shinozaki, T. Yanagida

Japanese Journal of applied physics   62 ( 7 ) 072002   2023.07  [Refereed]

Research paper (journal)   Domestic Co-author

TSL, OSL and scintillation properties of Tb-doped barium fluoride translucent ceramic

N. Kawano, T. Kato, D. Nakauchi, Y. Takebuchi, H. Fukushima, D. Shiratori, Luiz G. Jacobsohn, T. Yanagida

Optical Materials   141   113948   2023.07  [Refereed]

Research paper (journal)   International Co-author

Scintillation characteristics of transparent Eu2O3-BaO-TeO2 glass-ceramics

R. Nakamori, N. Kawano, D. Nakauchi, T. Kato, D. Shiratori, H. Fukushima, Y. Takebuchi, K. Shinozaki, T. Yanagida

Ceramics Internaitonal   49   15884   2023.05  [Refereed]

Research paper (journal)   Domestic Co-author

Optical and scintillation properties of organic–inorganic perovskite-type compounds with various hydroxyl alkyl amines or alkyl ether amines

T. Suto, N. Kawano, K. Okazaki, Y. Takebuchi, D. Shiratori, H. Fukushima, T. Kato, D. Nakauchi, T. Yanagida

Radiation physics and chemistry   209   110981   2023.04  [Refereed]

Research paper (journal)   Domestic Co-author

Scintillation properties of (H3NCnH2nNH3)PbBr4 (n = 8, 10, 12)

R. Nagaoka, N. Kawano, Y. Takebuchi, H. Fukushima, D. Shiratori, T. Kato, D. Nakauchi, T. Yanagida

Japanese Journal of applied physics   62   032005   2023.04  [Refereed]

Research paper (journal)   Domestic Co-author

Dosimetric and scintillation properties of Tm-doped BaF2 translucent ceramics

N. Kawano, T. Kato, D. Nakauchi, Y. Takebuchi, H. Fukushima, L.G. Jacobsohn, T. Yanagida

Journal of Materials Science: Materials in Electronics   34   962   2023.04  [Refereed]

Research paper (journal)   International Co-author

Scintillation and dosimeter properties of Pr2O3-doped Ga2O3–K2O–La2O3 glasses

N. Kawano, K. Shinozaki, D. Nakauchi, H. Kimura, G. Okada, T. Yanagida,

Materials Research Bulletin   158   122081   2023.02  [Refereed]

Research paper (journal)   Domestic Co-author

Photoluminescence and scintillation properties of organic-inorganic layered perovskite-type compounds (FC6H4C2H4NH3)2PbCl4 crystals

S. Matsuzawa, K. Okazaki, D, Nakauchi, N. Kawano, T. Suto, T. Kato, N. Kawaguchi, T. Yanagida

Optical Materials   136   113440   2023.02  [Refereed]

Research paper (journal)   Domestic Co-author

Scintillation properties of (C6H5CnH2nNH3)2PbCl4 (n = 1–4)

T. Suto, N. Kawano, K. Okazaki, Y. Takebuchi, H. Fukushima, T. Kato, D. Nakauchi, T. Yanagida

Japanese Journal of applied physics   62   010610   2023.01  [Refereed]

Research paper (journal)   Domestic Co-author

Effect of In-substitution on luminescence properties of organic-inorganic lead bromide layered perovskite-type scintillators

K. Okazaki, D. Nakauchi, N. Kawano, T. Kato, N. Kawaguchi, T. Yanagida

Radiation physics and chemistry   202   110514   2023.01  [Refereed]

Research paper (journal)   Domestic Co-author

Photoluminescence and scintillation properties of various organic– inorganic perovskite-type compounds with a diamine

R. Nagaoka, N. Kawano, Y. Takebuchi, H. Fukushima, T. Kato, D. Nakauchi, T. Yanagida

Japanese Journal of applied physics   61   110601   2023.01  [Refereed]

Research paper (journal)   Domestic Co-author

Dosimetric properties of Mn2+-Doped Ca2BO3Cl,

T. Wauke, S. Koide, N. Kawano, T. Kato, H. Fukushima, Y. Takebuchi, G. Okada, T. Yanagida,

Japanese Journal of applied physics   61   102007   2022.10  [Refereed]

Research paper (journal)   Domestic Co-author

Scintillation characteristics of Eu2O3-doped WO3–Al2O3–TeO2 glasses

N. Kawano, K. Shinozaki, T. Kato, D. Onoda, Y. Takebuchi, H. Fukushima, T. Yanagida

Journal of Luminescence   249   119003   2022.09  [Refereed]

Research paper (journal)   Domestic Co-author

Photoluminescence and scintillation properties of Eu2O3–BaO–Nb2O5–TeO2 glass and glass ceramics

R. Nakamori, N. Kawano, D. Nakauchi, T. Kato, H. Fukushima, Y. Takebuchi, K. Shinozaki, T. Yanagida

Journal of Materials Science: Materials in Electronics   33   20470 - 20478   2022.09  [Refereed]

Research paper (journal)   Domestic Co-author

Radiation response properties of Eu3+-doped K2O–Ta2O5–Ga2O3 glasses

N. Kawano, K. Shinozaki, T. Kato, D. Onoda, Y. Takebuchi, H. Fukushima, T. Yanagida

Ceramics International   48   9353 - 9361   2022.04  [Refereed]

Research paper (journal)   Domestic Co-author

Scintillation and thermoluminescence properties of Tm-doped BaCaBO3F

S. Koide, N. Kawano, T. Kato, H. Fukushima, Y. Takebuchi, D. Onoda, G. Okada, T. Yanagida

Optical Materials   126   112222   2022.04  [Refereed]

Research paper (journal)   Domestic Co-author

Photoluminescence and scintillation characteristics of (C6H5CnH2nNH3)2PbBr4 (n = 2, 3, 4)

R. Nagaoka, N. Kawano, D. Nakauchi, H. Kimura, M. Akatsuka, T. Yanagida

Japanese Journal of applied physics   61   SB1037   2022.02  [Refereed]

Research paper (journal)   Domestic Co-author

Scintillation characteristics of Nd3+-doped BaO–Al2O3–TeO2 glasses

A. Takaku, N. Kawano, H. Kimura, D. Nakauchi, M. Akatsuka, K. Shinozaki, T. Yanagida

Japanese Journal of applied physics   61   SB1034   2022.02  [Refereed]

Research paper (journal)   Domestic Co-author

Scintillation properties of organic–inorganic layered perovskite-type compounds with a methylphenethylamine

N. Kawano, M. Akatsuka, D. Nakauchi, H. Kimura, T. Yanagida

Japanese Journal of applied physics   61   SB1033   2022.02  [Refereed]

Research paper (journal)   Domestic Co-author

Evaluation of scintillation properties of organic-inorganic perovskite compounds — (C6H5C2H4NH3)2Pb1-xNixBr4

D. Onoda, M. Akatsuka, N. Kawano, D. Nakauchi, T. Kato, N. Kawaguchi, T. Yanagida

Japanese Journal of applied physics   61   SB1041   2022.02  [Refereed]

Research paper (journal)   Domestic Co-author

Effect of Cu-doping on photoluminescence properties of (C6H5C2H4NH3)2PbBr4

D. Onoda, M. Akatsuka, N. Kawano, T. Kato, D. Nakauchi, N. Kawaguchi, T. Yanagida

Sensors and Materials   34   585 - 594   2022.02  [Refereed]

Research paper (journal)   Domestic Co-author

Scintillation properties of organic-inorganic lead iodide perovskite single crystal having quantum well structures

K. Okazaki, D. Onoda, D. Nakauchi, N. Kawano, H. Fukushima, T. Kato, N. Kawaguchi, T. Yanagida

Sensors and Materials   34   575 - 584   2022.02  [Refereed]

Research paper (journal)   Domestic Co-author

Radiation response characteristics of Pr3+-activated SrO-Al2O3-TeO2 glasse

R. Nakamori, A. Takaku, N. Kawano, D. Onoda, Y. Takebuchi, H. Fukushima, T. Kato, K. Shinozaki, T. Yanagida

Sensors and Materials   34   707 - 716   2022.02  [Refereed]

Research paper (journal)   Domestic Co-author

Preparation and scintillation properties of the Eu3+-activated SrO–Al2O3–TeO2 glasses

R. Nakamori, N. Kawano, A. Takaku, D. Nakauchi, H. Kimura, M. Akatsuka, K. Shinozaki, T. Yanagida

Materials Research Bulletin   145   111547   2022.01  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Optical, scintillation and thermoluminescent properties of Eu2O3-doped K2O–La2O3–Ga2O3 glasses

N. Kawano, K. Shinozaki, D. Nakauchi, H. Kimura, M. Akatsuka, T. Yanagida

Radiation physics and chemistry   190   109785   2022.01  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Photoluminescence and scintillation characteristics of organic–inorganic layered perovskite-type compounds with a methoxyphenethylamine

N. Kawano, D. Nakauchi, M. Akatsuka, H. Kimura, T. Yanagida

Journal of Luminescence   241   118467   2022.01  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Radiation response characteristics of organic-inorganic perovskite-type compounds with a chlorophenetylamine

N. Kawano, A. Horimoto, H. Kimura, D. Nakauchi, M. Akatsuka, T. Yanagida

Materials Research Bulletin   142   111409   2021.10  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Development of (C6H5C2H4NH3)2Pb1-xCdxBr4 crystal scintillators with two-dimensional quantum-well structures

D. Onoda, M. Akatsuka, N. Kawano, D. Nakauchi, T. Kato, N. Kawaguchi, T. Yanagida

Journal of Luminescence   237   118157   2021.09  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Effects of Excitation Density on the Scintillation Properties of Organic-Inorganic Layered Perovskite-type Compounds

M. Koshimizu, N. Kawano, A. Kimura, S. Kurashima, M. Taguchi, Y. Fujimoto, and K. Asai

Sensors and Materials     2021.06  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation properties of (C6H5C2H4NH3)2Pb1-xSnxBr4 crystals having two-dimensional quantum-well structures

Daichi Onoda, Masaki Akatsuka, Naoki Kawano, Daisuke Nakauchi, Takumi Kato, Noriaki Kawaguchi, Takayuki Yanagida

Optical Materials   114   111002   2021.04  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Optical and radiation response characteristics of Eu2O3-doped K2O–Bi2O3–Ga2O3 glasses

Naoki Kawano, Kenji Shinozaki, Masaki Akatsuka, Hiromi Kimura, Daisuke Nakauchi, Takayuki Yanagida

Ceramics International   47   11596 - 11601   2021.04  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Photoluminescence, scintillation and thermoluminescent properties of Tb-doped BaCaBO3F

S. Koide, N. Kawano, M. Akatsuka, H. Kimura, D. Nakauchi, G. Okada, T. Yanagida

Radiation Measurements   143   106563   2021.04  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation and thermoluminescent properties of Dy-doped calcium borate chloride

Naoki Kawano, Hiromi Kimura, Masaki Akatsuka, Daisuke Nakauchi, Go Okada, Takayuki Yanagida

Optical Materials   112   110784   2021.02  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Rapid Synthesis of Quantum-Sized Organic–Inorganic Perovskite Nanocrystals in Glass

Kenji Shinozaki, Naoki Kawano

Scientific Reports ( Scientific Reports )  10 ( 1 )   2020.12  [Refereed]

Research paper (journal)   Domestic Co-author

© 2020, The Author(s). A bulk sample of an organic–inorganic (OI) perovskite crystal of (C6H5C2H4NH3)2PbBr4 with a layered structure showing excellent luminescent properties was rapidly synthesised. The raw materials of OI crystal were impregnated into nanoporous glass having 4-nm pores and dried, obtaining a translucent sample of OI nanocrystals in glass (OIiG). An absorbance shoulder was observed at E = 3.04 eV for OIiG, which was attributed to exciton bands, and photoluminescence (PL) duration times of τ1 = 2.8 ns and τ2 = 8.6 ns were recorded for OIiG. In contrast, for a single-crystal sample, E = 2.94 eV, τ1 = 4.1 ns, τ2 = 11.0 ns. Compared to those of the single-crystal sample, the OIiG has a higher absorbance energy, and the duration time was shorter. The exciton activation energy was 195 meV for OIiG, in contrast with 121 meV for single crystal. We propose that these changes are due to the size effect because the particle size (3–4 nm in diameter) in the OIiG is close to the Bohr radius of layer-structured OI crystals.

DOI PubMed

Radiation response properties of Dy-doped B2O3–Al2O3–SrO glasses

Naoki Kawano, Noriaki Kawaguchi, Go Okada, Yutaka Fujimoto, Takayuki Yanagida

Optik   224   165613   2020.12  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation properties of Dy-doped TeO2-Al2O3-BaO glasses

Akito TAKAKU, Naoki KAWANO, Hiromi KIMURA, Daisuke NAKAUCHI, Masaki AKATSUKA, Kenji SHINOZAKI, Takayuki YANAGIDA

Journal of the Ceramic Society of Japan   128   1024 - 1029   2020.12  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation and TSL properties of Eu-doped BaCaBO<inf>3</inf>F

Naoki Kawano, Go Okada, Hiromi Kimura, Takayuki Yanagida

Ceramics International ( Ceramics International )  46 ( 16 ) 26339 - 26345   2020.11  [Refereed]

Research paper (journal)   Domestic Co-author

© 2020 Elsevier Ltd and Techna Group S.r.l. We investigated photoluminescence (PL), scintillation and thermally-stimulated luminescence (TSL) properties of BaCaBO3F doped with different concentrations of Eu (0, 0.1, 1.0, and 10.0%) to develop phosphor materials for radiation measurement. The Eu-doped samples showed emissions with several sharp peaks due to the 4f-4f transitions of Eu3+ in PL and scintillation while no emission peak was observed in the undoped sample. The decay time constants of the Eu-doped samples in PL and scintillation were about 1.16–1.20 ms and 0.75–1.10 ms, respectively. In addition, the Eu-doped samples showed TSL due to the 4f-4f transitions of Eu3+. The thermal activation energies of the Eu-doped samples were calculated by TSL isothermal analysis, and the analysis suggested that eleven trapping centers with different activation energies involved in TSL might exist in the Eu-doped samples.

DOI

Photoluminescence and scintillation properties of (C6H5C2H4NH3)2Pb1−xZnxBr4 as a two-dimensional quantum-confined scintillator

Daichi Onoda, Masaki Akatsuka, Naoki Kawano, Daisuke Nakauchi, Takumi Kato, Noriaki Kawaguchi & Takayuki Yanagida

Journal of Materials Science: Materials in Electronics   31 ( 23 ) 1 - 7   2020.10  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation properties of Mn-doped methylammonium lead chloride crystals

Naoki Kawano, Masaki Akatsuka, Hiromi Kimura, Daisuke Nakauchi, Takumi Kato, Takayuki Yanagida

Journal of Materials Science: Materials in Electronics     2020.09  [Refereed]

Research paper (journal)   Domestic Co-author

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Organic–inorganic perovskite materials with a bulk structure MAPbX3 (MA: methylamine, X: halogen) have attracted much attention in various applications such as solar cells, photodiodes, and radiation detectors. Herein, we synthesized (CH3NH3)Pb1-xMnxCl3 (or Mn-doped MAPbCl3) crystals by inverse temperature crystallization method to develop scintillator materials and evaluated their photoluminescence (PL) and scintillation properties systematically. The Mn-doped MAPbCl3 crystals showed a sharp emission peak at approximately 410–430 nm with short decay times on the order of nanoseconds and a broad peak at approximately 600 nm with a long decay time on the order of milliseconds in PL and scintillation. Furthermore, pulse height spectra of the Mn-doped MAPbCl3 crystals with a shaping time of 1 µs were measured, and the obtained scintillation light yields were estimated to be 66 (x = 1), 82 (x = 5), and 67 (x = 10) photons/5.5 MeV-α. Moreover, afterglow levels of the Mn-doped MAPbCl3 crystals were found to be 161 (x = 1), 264 (x = 5) and 170 (x = 10) ppm, which were comparable to a previously reported afterglow level of Tl-doped CsI.

DOI

Scintillation properties of organic-inorganic layered perovskite-type nanocrystals in glass

Naoki Kawano, Kenji Shinozaki, Daisuke Nakauchi, Hiromi Kimura, Takayuki Yanagida

Journal of Applied Physics   127   213103   2020.06  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation and dosimetric properties of Tb-doped CaF<inf>2</inf> translucent ceramics synthesized by the spark plasma sintering method

Naoki Kawano, Daisuke Nakauchi, Fumiya Nakamura, Takayuki Yanagida

Journal of Asian Ceramic Societies ( Journal of Asian Ceramic Societies )  8 ( 2 ) 484 - 491   2020.04  [Refereed]

Research paper (journal)   Domestic Co-author

© 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of The Korean Ceramic Society and The Ceramic Society of Japan. CaF2 translucent ceramics with different concentrations of Tb were synthesized by the spark plasma sintering (SPS) method, and their photoluminescence, scintillation and dosimetric properties were characterized. The Tb-doped samples exhibited scintillation with several sharp peaks across the range from 365–630 nm due to 4 f-4 f transitions of Tb3+ and with a broad peak at approximately 300 nm due to self-trapped excitons. Among the sample investigated, the scintillation intensity in the 365–630 nm range was highest for the 0.5% Tb-doped sample. As a dosimetric property, the Tb-doped samples exhibited thermally-stimulated luminescence (TSL) with a glow peak at approximately 90°C, and with a TSL response in a linear relationship to the X-ray dose over the dose range from 0.001 to 1 mGy. Optically stimulated luminescence (OSL) due to the 4 f-4 f transitions of Tb3+ was detected in the Tb-doped samples, moreover and the lowest detectable limit of OSL was at most 100 mGy.

DOI

Photoluminescence and scintillation properties of organic–inorganic perovskite-type compounds with bromophenethylamine

Atsushi Horimoto, Naoki Kawano, Daisuke Nakauchi, Hiromi Kimura, Masaki Akatsuka, Takayuki Yanagida

Sensors and Materials ( Sensors and Materials )  32 ( 4 ) 1395 - 1404   2020.04  [Refereed]

Research paper (journal)   Domestic Co-author

© MYU K.K. (n-BrC6H4C2H4NH3)2PbBr4 (n-BrPhe) (n = 2, 3, 4) single crystals were synthesized with the aim of enhancing the scintillation light yield of (C6H5C2H4NH3)2PbBr4 (Phe), and their photoluminescence (PL) and scintillation characteristics were evaluated. A sharp PL peak due to the exciton emissions from the inorganic layer was observed at 390–420 nm in the n-BrPhe samples. They had lifetimes of 4.7 ns (2-BrPhe), 2.1 ns (3-BrPhe), and 0.9 ns (4-BrPhe) owing to the exciton recombination in the inorganic layer under 340 nm excitation. Regarding scintillation, a sharp peak due to exciton emissions from the inorganic layer was detected at 410–440 nm under X-ray irradiation, and the decay time constants under X-ray irradiation were 2.3 ns (2-BrPhe), 2.0 ns (3-BrPhe), and 2.1 ns (4-BrPhe). Moreover, the scintillation light yields under gamma-ray irradiation from 241Am (59.5 keV) were found to be 3100 (2-BrPhe), 2200 (3-BrPhe), and 5900 photons/MeV (4-BrPhe), which were lower than that of Phe (18000 photons/MeV).

DOI

Scintillation properties of organic–inorganic perovskite-type compounds with fluorophenethylamine

Atsushi Horimoto, Naoki Kawano, Daisuke Nakauchi, Hiromi Kimura, Masaki Akatsuka, Takayuki Yanagida

Optical Materials ( Optical Materials )  101   2020.03  [Refereed]

Research paper (journal)   Domestic Co-author

© 2020 Elsevier B.V. (n-FC6H4C2H4NH3)2PbBr4 {n-FPhe} (n = 2, 3, 4) single crystals were prepared by the poor solvent diffusion method, and their photoluminescence (PL) and scintillation characteristics were evaluated. In PL, a sharp peak due to exciton recombination in the inorganic layer was observed around 400–420 nm in all the samples. Furthermore, they showed a short decay time of 3.4 ns (2-FPhe), 2.7 ns (3-FPhe) and 1.6 ns (4-FPhe) due to the exciton recombination in the inorganic layer under excitation wavelength of 280 nm. In scintillation, they showed a sharp scintillation peak due to excitons recombination in the inorganic layer approximately at 430 nm under X-ray irradiation. The scintillation decay time derived from exciton recombination in the inorganic layer under X-ray irradiation was 5.3 ns (2-FPhe), 6.9 ns (3-FPhe) and 2.8 ns (4-FPhe). Furthermore, the light yield under 241Am gamma-ray irradiation (59.5 keV) was estimated to be 3300 (2-FPhe), 12000 (3-FPhe) and 8300 photons/MeV (4-FPhe).

DOI

Scintillation and TSL properties of Nd-doped TeO<inf>2</inf>–Al<inf>2</inf>O<inf>3</inf>-WO<inf>3</inf> glasses

Naoki Kawano, Hiromi Kimura, Daisuke Nakauchi, Kenji Shinozaki, Takayuki Yanagida

Solid State Sciences ( Solid State Sciences )  100   2020.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2020 Elsevier Masson SAS We evaluated photoluminescence (PL) and scintillation properties of TeO2–Al2O3-WO3 glasses with different concentrations of Nd (0, 0.1, 0.5 and 1.0 mol.%). The glass samples were fabricated by the conventional melt-quenching method. The Nd-doped samples showed sharp emission peaks due to the 4f-4f transitions of Nd3+ in PL and scintillation. The 0.5% and 1.0% Nd-doped samples showed high PL quantum efficiencies and scintillation intensities among the sample tested. Furthermore, the decay time constants for the Nd-doped samples in PL and scintillation were 140–206 and 110–123 μs, respectively. In addition, the undoped and Nd-doped samples showed thermally stimulated luminescence (TSL) with a weak glow peak approximately at 285 °C, and the detection limit of TSL (10 Gy) was much higher than that of common TSL materials.

DOI

Scintillation and dosimetric properties of Dy-doped CaF<inf>2</inf> translucent ceramic and single crystal

Naoki Kawano, Daisuke Nakauchi, Fumiya Nakamura, Takayuki Yanagida

Journal of the Ceramic Society of Japan ( Journal of the Ceramic Society of Japan )  128 ( 2 ) 57 - 61   2020.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2020 The Ceramic Society of Japan. All rights reserved. We synthesized a Dy-doped CaF2 translucent ceramic by the spark plasma sintering method, and investigated its scintillation and dosimetric properties compared with those of the single crystal. Both the samples showed sharp peaks across 480670nm due to the 4f4f transitions of Dy3+, and a broad peak approximately at 300nm due to the self-trapped excitons. The decay time constants of both the samples in scintillation were approximately 5 ms, which was close to those for the 4f4f transitions of Dy3+. Regarding thermally-stimulated luminescence, the translucent ceramic exhibited higher sensitivity than the single crystal, and the dynamic range was at least 0.01100 mGy. In addition, both the samples showed optically stimulated luminescence due to the 4f4f transitions of Dy3+ during 590nm stimulation light, but the lowest detection limit of both the samples was approximately 10mGy.

DOI

Luminescence and scintillation properties of (C<inf>6</inf>H<inf>5</inf>(CH<inf>2</inf>)<inf>2</inf>NH<inf>3</inf>)<inf>2</inf>(Ba,Pb)Br<inf>4</inf> with self-organized bi-dimensional quantum-well structures

Daisuke Nakauchi, Naoki Kawano, Noriaki Kawaguchi, Takayuki Yanagida

Japanese Journal of Applied Physics ( Japanese Journal of Applied Physics )  59 ( SC )   2020.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2019 The Japan Society of Applied Physics. (C6H5(CH2)4NH3)2BaxPb1-xBr4 (x = 0, 0.1, 0.25 and 0.5) crystals were prepared by the solvent diffusion method to evaluate the scintillation properties. The samples exhibit photoluminescence and scintillation with a sharp emission peaking around 440 nm due to excitons, and the decay time is dominantly several nanoseconds. The pulse height spectrum under 137Cs gamma-ray irradiation demonstrates that the scintillation light yields of (C6H5(CH2)2NH3)2Ba0.25Pb0.75Br4 and (C6H5(CH2)2NH3)2Ba0.5Pb0.5Br4 crystals are approximately 19 000 ph MeV-1

DOI

Development of scintillating 2D quantum confinement materials — (C<inf>6</inf>H<inf>5</inf>C<inf>2</inf>H<inf>4</inf>NH<inf>3</inf>)<inf>2</inf>Pb<inf>1−x</inf>Sr<inf>x</inf>Br<inf>4</inf>

Masaki Akatsuka, Naoki Kawano, Takumi Kato, Daisuke Nakauchi, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment ( Elsevier )  954   2020.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 (C6H5C2H4NH3)2Pb1−xSrxBr4 (x=0.1, 0.25 and 0.5) single crystals were grown by the poor-solvent diffusion method to evaluate their scintillation properties. When X-rays were irradiated upon the sample, the solids demonstrated scintillation with a spectrum of band peaking around 430 nm due to exciton emission from the inorganic layer. The pulse height spectra under 137Cs gamma-rays irradiation were measured by using (C6H5C2H4NH3)2Pb1−xSrxBr4 (x=0.1 and 0.25) crystals, and the estimated scintillation light yields were 19,700 and 18,500 ph/MeV for x=0.1 and 0.25 samples, respectively.

DOI

Photoluminescence and scintillation properties of (C<inf>6</inf>H<inf>5</inf>C<inf>2</inf>H<inf>4</inf>NH<inf>3</inf>)<inf>2</inf>Pb<inf>1-x</inf>Mn<inf>x</inf>Br<inf>4</inf>

Naoki Kawano, Daisuke Nakauchi, Hiromi Kimura, Masaki Akatsuka, Kosuke Takahashi, Fumito Kagaya, Takayuki Yanagida

Japanese Journal of Applied Physics ( Japanese Journal of Applied Physics )  58 ( 8 )   2019.07  [Refereed]

Research paper (journal)   Domestic Co-author

© 2019 The Japan Society of Applied Physics. We characterized photoluminescence (PL) and scintillation properties of (C6H5C2H4NH3)2Pb1-xMnxBr4 (x = 0.025, 0.05) synthesized by the poor-solvent diffusion method. The Mn-doped samples showed exciton emissions from the inorganic layer approximately at 410 nm while they exhibited an emission approximately at 590 nm due to the 4T1-6A1 transitions of Mn2+ in PL and scintillation. Moreover, the pulse height spectra of the Mn-doped samples were measured under 241Am gamma-ray irradiation (59.5 keV), and the scintillation light yield was estimated to be 1600 (x = 0.025), 1300 (x = 0.05) photons/MeV. In addition, the afterglow level of the Mn-doped samples was found to be 41 ppm (x = 0.025) and 21 ppm (x = 0.05). These afterglow levels were almost equivalent to those of Bi4Ge3O12 and CdWO4, which are famous for low afterglow levels.

DOI

Photoluminescence and scintillation properties of Eu-doped TeO<inf>2</inf>-Al<inf>2</inf>O<inf>3</inf>-BaO glasses

Naoki Kawano, Hiromi Kimura, Atsushi Horimoto, Kenji Shinozaki, Takayuki Yanagida

Journal of Materials Science: Materials in Electronics ( Journal of Materials Science: Materials in Electronics )  30 ( 12 ) 11468 - 11474   2019.06  [Refereed]

Research paper (journal)   Domestic Co-author

© 2019, Springer Science+Business Media, LLC, part of Springer Nature. We synthesized TeO2-Al2O3-BaO glasses with different concentrations of Eu (0, 0.1, 0.5, 1.0 and 5.0 mol%) by the conventional melt-quenching technique to develop scintillator materials. After the synthesis, photoluminescence (PL) and scintillation properties of the samples were investigated systematically. The Eu-doped samples exhibited emissions with peaks approximately at 590 and 620 nm due to the 4f-4f transitions of Eu3+ in PL and scintillation. Among the sample investigated, the 5.0% Eu-doped sample showed the highest PL and scintillation intensities. In addition, decay time constants of the Eu-doped samples in PL and scintillation were about 0.91–0.94 and 0.37–0.51 ms, respectively. Furthermore, the afterglow levels of the samples were estimated to be 179–245 ppm, which was approximately one order of magnitude higher than those of Bi4Ge3O12 and CdWO4.

DOI

Photoluminescence, scintillation and TSL properties of Tb-doped strontium aluminoborate glasses

Naoki Kawano, Noriaki Kawaguchi, Go Okada, Yutaka Fujimoto, Takayuki Yanagida

Radiation Measurements   124   69 - 73   2019.05  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Photoluminescence, scintillation and TSL properties of Eu-doped Al<inf>2</inf>O<inf>3</inf> transparent ceramics synthesized by spark plasma sintering method

Naoki Kawano, Takumi Kato, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Optical Materials ( Optical Materials )  88   67 - 73   2019.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier B.V. We synthesized Al2O3 transparent ceramics doped with different concentrations of Eu (0.001, 0.01, 0.1 and 1.0%) by the spark plasma sintering (SPS) method, and then we investigated their photoluminescence (PL), scintillation and thermally-stimulated luminescence (TSL) properties. In the PL, the samples showed a broad emission peak at 400 nm due to the 5d-4f transitions of Eu2+ and several sharp emission peaks across 550–750 nm due to the 4f-4f transitions of Eu3+ and the 3d-3d transitions of Cr3+ impurity ion. In addition to these peaks over 550–750 nm, in scintillation, the samples exhibited two broad peaks over 300–400 nm possibly due to not the 5d-4f transitions of Eu2+ but F and F+ centers. In TSL, the glow curve consisted of peaks at approximately 100, 160, 210 and 320 °C. The TSL intensity of the 0.001% Eu-doped sample was the highest, and the TSL response was confirmed to be linear to irradiated X-ray dose in the range from 0.1 to 1000 mGy.

DOI

Optical and radiation-induced luminescence properties of Sn-doped magnesium aluminoborate glasses

D. Nakauchi, G. Okada, Y. Fujimoto, N. Kawano, N. Kawaguchi, T. Yanagida

Physics and Chemistry of Glasses: European Journal of Glass Science and Technology Part B   60 ( 1 ) 10 - 14   2019.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2019 Ukrainian State University of Chemical Technology. All rights reserved. We have investigated the optical, radioluminescence and thermoluminescence (TL) properties of Sn-doped magnesium aluminoborate glasses. The glass samples were synthesised by the conventional melt-quenching technique using an alumina crucible under ambient atmosphere. The glass samples exhibit photoluminescence and radioluminescence with a broad emission predominantly due to Sn 2+ , and the decay time constants have typical values for Sn 2+ . The TL glow curves after x-ray irradiation are approximated by a sum of three Gaussian functions at around 130, 180 and 380°C. The TL intensity increases monotonically with irradiated x-ray dose from 1 mGy to 10000 mGy.

DOI

Thermoluminescence characteristics of Nd-doped LiCaAlF6 single crystal

Noriaki Kawaguchi, Daisuke Nakauchi, Go Okada, Naoki Kawano, Takayuki Yanagida

Journal of Luminescence   206   634 - 638   2019.02  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation and photoluminescence properties of Sr<inf>2</inf>CeO<inf>4</inf> ceramics

Takumi Kato, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Masanori Koshimizu, Takayuki Yanagida

Optical Materials ( Elsevier B.V. )  87   139 - 144   2019.01  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier B.V. We have investigated scintillation and photoluminescence (PL) properties of Sr2CeO4 ceramics. The ceramic samples were synthesized by the solid state reaction method sintered at different temperatures (1100, 1200, 1300 and 1400 °C). All the Sr2CeO4 ceramic samples showed PL spectrum with a broad feature peaking around 460 nm. From decay constants of the PL emission, it was confirmed that the origin was due to the charge transfer (CT) transitions of O2—Ce4+ ions. In addition, all the samples showed scintillation induced by X-rays with a spectrum peaking around 500 nm as similarly seen in PL. All of the samples exhibited a clear photoabsorption peak in the pulse height spectra measured under 137Cs γ-ray irradiation, and the absolute scintillation light yield (LY) was the highest for the sample sintered at 1200 °C, and the value was 3200 ph/MeV.

DOI

Tb³⁺-doped BaF<inf>2</inf>-Al<inf>2</inf>O<inf>3</inf>-B<inf>2</inf>O<inf>3</inf> glass and glass-ceramic for radiation measurements

Go Okada, Kenji Shinozaki, Takayuki Komatsu, Naoki Kawano, Noriaki Kawaguchi, Takayuki Yanagida

Journal of Non-Crystalline Solids   501   111 - 115   2018.12  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier B.V. Tb3+-doped BaF2-Al2O3-B2O3 glass and glass-ceramic were synthesized, and the luminescence properties were investigated for potential applications in radiation measurements. The glass-ceramic can be obtained by heat-treating the glass, and it includes BaAlBO3F2 crystalline phase in glass matrix. The photoluminescence (PL) quantum yield is higher for glass than glass-ceramic. The reason can be due to the difference of the number of F− and O2– ions surrounding Tb3+ activator ion. The lifetime of PL is slightly shorter than that of scintillation suggesting energy transfer process from the host to Tb3+ is involved. The time-response of scintillation has significantly slow rise feature possibly due to excited state absorption. Both glass and glass-ceramic show efficient optically-stimulated luminescence (OSL) with equivalent sensitivities despite the large difference of PL efficiency. The latter observation suggests that the glass-ceramic includes large number of OSL active centres than glass. The OSL dynamic range was confirmed to be at least 101–104 mGy.

DOI

Optical and scintillation properties of 30BaO–(70-x)TiO<inf>2</inf>–xGeO<inf>2</inf> (x = 50, 55, 60) glass-ceramics

Takayuki Yanagida, Hirokazu Masai, Go Okada, Naoki Kawano, Noriaki Kawaguchi

Journal of Non-Crystalline Solids   501   106 - 110   2018.12  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier B.V. 30BaO–(70-x)TiO2–xGeO2 (x = 50, 55, 60; BTG) glass and glass-ceramics samples were prepared by a melt-quenching method, and the optical and X-ray induced scintillation properties were investigated. In this study, we prepared twelve different samples: three different compositions (BTGx; x = 50, 55 and 60), two different melting temperatures (1250 and 1550 °C), and with/without crystallization process. The crystallization phenomenon was confirmed by XRD analysis. In photoluminescence spectra, only one broad emission peak at 520 nm was observed in the glass samples, while another peak was observed in glass-ceramic samples at 450 nm in addition to 520 nm peak. The similar tendency was also observed in X-ray induced scintillation spectra. According to the crystallization, the scintillation efficiency was enhanced.

DOI

Scintillation and dosimeter properties of Ca-doped MgO transparent ceramics

Narumi Kumamoto, Takumi Kato, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms ( Elsevier B.V. )  435   313 - 317   2018.11  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier B.V. We have synthesized 0.001, 0.01 and 0.1% Ca-doped MgO transparent ceramics by the Spark Plasma Sintering (SPS) method, and then we investigated the optical, scintillation and dosimeter properties. In scintillation spectra, some emission bands appeared around 340, 400, 440, 600 and 750 nm. After X-ray irradiation, all the Ca-doped samples showed TSL with a glow peak ∼140 °C, and the 0.01% Ca-doped sample showed an additional broad peak ∼250 °C. The TSL spectrum consists of a broad peak over 300–500 nm and some peaks around 600 and 750 nm. The TSL response was confirmed to linearly increase with irradiation dose over a dose range from 0.1 to 100 mGy.

DOI

Radiation-induced luminescence centres in Sm:MgF<inf>2</inf> ceramics

Go Okada, Fumiya Nakamura, Naoki Kawano, Noriaki Kawaguchi, Safa Kasap, Takayuki Yanagida

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms   435   268 - 272   2018.11  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier B.V. We have prepared Sm:MgF2 ceramics by the spark plasma sintering technique and studied the radio-photoluminescence (RPL) properties. RPL is a phenomenon seen in selected phosphors in which a new photoluminescence (PL) emission centre is generated by ionizing radiations such as X-rays. In the present system, RPL is observed with two different emissions in the blue and near infrared (NIR) ranges due to M(C2h) and M(C1) centres. The dynamic range using the former centre is in the high dose range above 100 Gy while the former centres have a sensitivity below 100 Gy. In addition, heat-treating an irradiated 0.01%Sm:MgF2 sample induces the reduction of the Sm3+-ion, i.e. Sm3+ → Sm2+). These centres are metastable, and their concentration can be increased or decreased by heat-treatment and exposing to UV light.

DOI

Photoluminescence and scintillation properties of Eu-doped strontium aluminate crystals

Daisuke Nakauchi, Go Okada, Koshimizu Masanori, Naoki Kawano, Noriaki Kawaguchi, Takayuki Yanagida

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms   435   273 - 277   2018.11  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier B.V. Eu-doped SrAl12O19, SrAl4O7, Sr4Al14O25 and SrAl2O4 bulk crystals were successfully synthesized by the floating zone method. The samples exhibit photoluminescence and scintillation with an intense broad emission due to the 5d-4f transitions of Eu2+ in the visible range, and Eu:SrAl12O19 shows additional several sharp emissions owing to Eu3+. The Eu2+ emission blue-shifts as the Al-ratio increases. Pulse height spectrum measurements under 137Cs γ-ray irradiation demonstrated a clear photoabsorption peak, in which the scintillation light yields were estimated to be 6,900 (Eu:SrAl12O19), 700 (Eu:SrAl4O7), 6,500 (Eu:Sr4Al14O25) and 42,000 (Eu:SrAl2O4) photons/MeV.

DOI

Dosimetric properties of Al<inf>2</inf>O<inf>3</inf> transparent ceramics doped with C

Takumi Kato, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms   435   296 - 301   2018.11  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier B.V. We have investigated scintillation and thermally-stimulated luminescence (TSL) dosimetric properties of Al2O3 transparent ceramics doped with different concentrations of C ions (0.001, 0.01 and 0.1%). The samples were synthesized by the Spark Plasma Sintering (SPS) technique. All the samples showed scintillation with emission peaks at 310, 410 and 693 nm under X-ray irradiation. Based on the scintillation decay times measured, the origins of emissions at 310, 410 and 693 nm were attributed to F+ centers, F centers and Cr3+ impurity ions, respectively. The samples show notable TSL with a glow curve consisting of peaks at 30, 100, 165, 230, 330 and 405 °C with much higher intensities than those of undoped Al2O3 transparent ceramics. A TSL response was confirmed to be linear to the irradiation dose over a range from 0.1 to 1000 mGy.

DOI

Scintillation and TSL properties of Tb-doped NaPO<inf>3</inf>-Al(PO<inf>3</inf>)<inf>3</inf> glasses

Naoki Kawano, Masaki Akatsuka, Hiromi Kimura, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Radiation Measurements ( Radiation Measurements )  117   52 - 56   2018.10  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier Ltd We synthesized NaPO3-Al(PO3)3 glasses with different concentrations of Tb (0.3, 1.0, 3.0 and 10.0 mol%) by the conventional melt-quenching technique. After the synthesis, their photoluminescence (PL), scintillation and TSL properties were characterized systematically. All the glass samples showed intense PL and scintillation having a spectrum of sharp peaks at around 490, 540, 590 and 620 nm due to the 4f-4f transitions of Tb3+. The intensities of PL and scintillation were the highest for the 10.0% Tb-doped glass among the samples investigated. In thermally-stimulated luminescence (TSL), the intensity was the highest for the 1.0% Tb-doped sample. We also demonstrated dose response of TSL, and the 0.3% and 1.0% Tb-doped samples exhibited a linear response to X-ray dose over a dose range of 10–10000 mGy.

DOI

Comparative study of scintillation and dosimetric properties between Tm-doped CaF<inf>2</inf> translucent ceramic and single crystal

Naoki Kawano, Daisuke Nakauchi, Kentaro Fukuda, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Japanese Journal of Applied Physics   57 ( 10 )   2018.10  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 The Japan Society of Applied Physics. 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.

DOI

Scintillation properties of SrF<inf>2</inf> translucent ceramics and crystal

Takumi Kato, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Kentaro Fukuda, Takayuki Yanagida

Optik ( Elsevier GmbH )  168   956 - 962   2018.09  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier GmbH We have developed SrF2 translucent ceramic by using the spark plasma sintering (SPS) method, and investigated scintillation properties and thermally stimulated luminescence (TSL) glow curves, in comparison with a SrF2 crystal. Both of the samples showed scintillation with emission peaks at 300 nm under X-ray irradiation. Based on the scintillation decay times measured, the origin of emission at 300 nm was attributed to self-trapped excitation. The scintillation light yield of the SrF2 translucent ceramic was evaluated to be about 8900 photons/MeV under 57Co γ-rays. In addition, the afterglow level of the translucent ceramic was lower than that of the crystal.

DOI

Scintillation and dosimetric properties of Ce-doped ⁶LiF-CaF<inf>2</inf> eutectic composites

Naoki Kawano, Noriaki Kawaguchi, Kentaro Fukuda, Go Okada, Takayuki Yanagida

Optical Materials ( Elsevier B.V. )  82   60 - 64   2018.08  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier B.V. Scintillation and dosimetric properties of 6LiF-CaF2 eutectic composites doped with different concentrations of Ce (0, 0.1 and 0.5%) were investigated. The Ce-doped samples showed scintillation due to the 5 d-4f transitions of Ce3+ and self-trapped excitons (STE) at 320–340 and 300 nm, respectively. Furthermore, the Ce-doped samples exhibited thermally-stimulated luminescence (TSL) with glow peaks around 150 °C after X-ray irradiation of 1000 mGy. The TSL response of the 0.5% Ce-doped sample increased monotonically with X-ray dose over a dose range of 0.1–1000 mGy. Moreover, the Ce-doped samples showed optically-stimulated luminescence (OSL) with peaks at 320–340 nm due to the 5 d-4f transitions of Ce3+ under 630 nm stimulation light after X-ray irradiation of 1000 mGy.

DOI

Dosimetric properties of thulium-doped strontium aluminoborate glasses

Naoki Kawano, Noriaki Kawaguchi, Go Okada, Yutaka Fujimoto, Takayuki Yanagida

Sensors and Materials ( Sensors and Materials )  30 ( 7 ) 1539 - 1546   2018.08  [Refereed]

Research paper (journal)   Domestic Co-author

© MYU K.K. We investigated the photoluminescence (PL), scintillation, and dosimetric properties of strontium aluminoborate glasses with different thulium (Tm) concentrations of 0.1, 0.5, 1.0, and 5.0%. The Tm-doped glasses were synthesized by the conventional melt-quenching technique. In the PL and scintillation spectra, the Tm-doped samples showed a sharp peak at 460 nm due to the 4f-4f (1D2→3F4) transitions of Tm3+. Among the samples tested, the 0.5% Tm-doped sample exhibited the highest intensity in PL and scintillation. In thermally stimulated luminescence (TSL), the Tm-doped samples showed a broad glow peak around 100 °C after X-ray irradiation of 10000 mGy. The 0.5% Tm-doped sample also showed the highest TSL intensity. Furthermore, the 0.1-1.0% Tm-doped samples exhibited a linear response against X-ray doses over a range of 10-1-104 mGy.

DOI

Comparative study of scintillation properties of Ga<inf>2</inf>O<inf>3</inf> single crystals and ceramics

Yuki Usui, Takumi Kato, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Journal of Luminescence ( Elsevier B.V. )  200   81 - 86   2018.08  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier B.V. A series of bulk Ga2O3 were prepared by four different methods (Floating Zone (FZ), Edge-defined Film-fed Grown (EFG), spark plasma sintering (SPS) and conventional sintering in air) to obtain in single crystal and ceramic forms. In photoluminescence (PL), all the samples showed defect-related luminescence due to recombination between donors and acceptors; however, the peak position was different in each sample. The PL and scintillation decay curves were approximated by a sum of two exponential decay functions, and emission origins were attributed to to recombination between donors and acceptors. Pulse height spectrum of 241Am α-ray irradiation was demonstrated by using the present samples, and we confirmed that the one prepared by the EFG method indicated a clear full energy absorption peak, and the estimated light yield was 3200 ± 320 ph/5.5 MeV-α.

DOI

Characterizations of Ce-doped Y<inf>4</inf>Al<inf>2</inf>O<inf>9</inf> crystals for scintillator applications

Go Okada, Masaki Akatsuka, Hiromi Kimura, Masaki Mori, Naoki Kawano, Noriaki Kawaguchi, Takayuki Yanagida

Sensors and Materials   30 ( 7 ) 1547 - 1554   2018.08  [Refereed]

Research paper (journal)   Domestic Co-author

© MYU K.K. Ce-doped Y4Al2O9 (YAM) crystals were grown by the floating zone method, and several different characterizations were conducted for scintillator applications. Both photoluminescence (PL) and scintillation show emissions predominantly due to the 5d-4f transitions of Ce3+ over 400-600 nm. The luminescence lifetime is approximately 10 ns for PL while the scintillation decay curve is best fitted by a second-order exponential decay function with the lifetimes of approximately 30 and 300 ns. These lifetimes are faster than that for Ce:Y3Al5O12 (YAG) (~120 ns) and close to that of Ce:YAlO3 (YAP) (~30 ns). The Ce-doped YAM shows a relatively high afterglow signal induced by X-rays (2 ms pulse) possibly due to the inclusion of a large number of defect centers. Pulse height spectroscopy was demonstrated under alpha-ray irradiation, and a successful sample showed a full-energy peak.

DOI

Scintillation characteristics of Pr:CaF<inf>2</inf> crystals for charged-particle detection

Noriaki Kawaguchi, Hiromi Kimura, Masaki Akatsuka, Go Okada, Naoki Kawano, Kentaro Fukuda, Takayuki Yanagida

Sensors and Materials ( Sensors and Materials )  30 ( 7 ) 1585 - 1590   2018.06  [Refereed]

Research paper (journal)   Domestic Co-author

© MYU K.K. The scintillation properties of Pr:CaF2 were studied in comparison with those of Eu:CaF2 under α-ray excitation using a sealed source of 241Am. The relative light yields of the Pr:CaF2 crystals were approximately 0.6-13% of the Eu:CaF2 crystal that is known as a conventional scintillator for charged-particle detection. The scintillation decay times of the Pr:CaF2 crystals were significantly faster than that of the Eu:CaF2 crystal. Therefore, the Pr:CaF2 crystals can be used for charged-particle measurements with high count rates.

DOI

Scintillation and optical properties of Sn-doped Ga<inf>2</inf>O<inf>3</inf> single crystals

Yuki Usui, Daisuke Nakauchi, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Journal of Physics and Chemistry of Solids   117   36 - 41   2018.06  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier Ltd Sn-doped Ga2O3 single crystals were synthesized by the Floating Zone (FZ) method. In photoluminescence (PL) under the excitation wavelength of 280 nm, we observed two types of luminescence: (1) defect luminescence due to recombination of the donor/acceptor pairs which appears at 430 nm and (2) the nsnp-ns2 transitions of Sn2+ which appear at 530 nm. The PL and scintillation decay time curves of the Sn-doped samples were approximated by a sum of exponential decay functions. The faster two components were ascribed to the defect luminescence, and the slowest component was owing to the nsnp-ns2 transitions. In the pulse height spectrum measurements under 241Am α-rays irradiation, all the Sn-doped Ga2O3 samples were confirmed to show a full energy absorption peak but the undoped one. Among the present samples, the 1% Sn-doped sample exhibited the highest scintillation light yield (1,500 ± 150 ph/5.5 MeV-α).

DOI

Scintillation and dosimeter properties of ⁶LiF/CaF<inf>2</inf>:Eu eutectic composites

Naoki Kawano, Noriaki Kawaguchi, Kentaro Fukuda, Go Okada, Takayuki Yanagida

Journal of Materials Science: Materials in Electronics ( Springer New York LLC )  29 ( 11 ) 8964 - 8969   2018.06  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. We investigated scintillation and dosimeter properties of 6LiF/CaF2 eutectic composites doped with different concentrations of Eu (0.005, 0.02, 0.1, 0.3, and 1.0). In the photoluminescence (PL) and scintillation spectra, an emission peak at 430 nm due to the 5d–4f transitions of Eu2+ was observed. The intensity of PL and scintillation for 6LiF/CaF2:0.005%Eu was the highest among the samples tested. In thermally stimulated luminescence (TSL), several glow peaks of 6LiF/CaF2:0.005%Eu were observed after X-ray irradiation of 1000 mGy. The TSL response exhibited a linear response against X-ray dose over a dose range of 1–10,000 mGy. In optically stimulated luminescence (OSL), an emission peak was observed at 430 nm during a stimulation by 630 nm light after X-ray irradiation of 1000 mGy. The OSL intensity was the highest for 6LiF/CaF2:0.005%Eu among all the samples investigated.

DOI

Non-doped Li<inf>2</inf>CO<inf>3</inf> ceramics as a new radio-photoluminescence material

Fumiya Nakamura, Takumi Kato, Go Okada, Naoki Kawano, Noriaki Kawaguchi, Takayuki Yanagida

Materials Letters ( Elsevier B.V. )  221   51 - 53   2018.06  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 In this letter, we repot a new radio-photoluminescence (RPL) material. The RPL was observed non-doped Li2CO3 ceramics sintered in vacuum. Under 340 ± 40 nm excitation, a photoluminescence (PL) emission peak appeared around 470 nm, the intensity of which increases with X-ray irradiation dose. The RPL signal was very sensitive to X-ray dose, and the response signal was measurable as low as 0.1 mGy although the synthesis and measurement set-up were not optimized. This sensitivity is equivalent to that of commercial RPL dosimeters. In addition, the effective atomic number of Li2CO3 (Zeff = 7.32) is closer to that of biological tissue than any other dosimeter materials used in practice. From these reasons, we believe that this material should be a promising candidate for RPL dosimeters.

DOI

Scintillation properties of YAlO<inf>3</inf> doped with Lu and Nd perovskite single crystals

Masaki Akatsuka, Yuki Usui, Daisuke Nakauchi, Takumi Kato, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Optical Materials   79   428 - 434   2018.05  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier B.V. YAlO3 (YAP) single crystals doped with Lu and Nd were grown by the Floating Zone (FZ) method to evaluate their scintillation properties particularly emissions in the near-infrared (NIR) range. The Nd concentration was fixed to 0 or 1 mol% while the Lu concentration was varied from 0 to 30%. When X-ray was irradiated, the scintillation of Nd-doped samples was observed predominantly at 1064 nm due to 4F3/2 → 4I11/2 transition of Nd3+. In contrast, a weak emission around 700 nm appeared in the samples doped with only Lu, and the emission origin was attributed to defect centers. In the Nd3+-doped samples, the decay time was 94–157 μs due to the 4f-4f transitions of Nd3+ whereas the Lu-doped samples showed signal with the decay time of 1.45–1.54 ms. The emission origin of the latter signal was attributed to the perovskite lattice defect.

DOI

PL and TSL properties of tin-doped zinc sodium phosphate glasses

Shotaro Hirano, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Radiation Measurements ( Elsevier Ltd )  112   16 - 20   2018.05  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier Ltd Photoluminescence (PL) and thermally-stimulated luminescence (TSL) properties of Sn-doped zinc sodium phosphate glasses were evaluated. We synthesized the glass samples by the conventional melt-quenching method under ambient atmosphere. The glasses were highly transparent in 400–2700 nm. Depending on the concentration of Sn, PL quantum yield (QY) ranged from 7.7 to 25.7%, and the PLQY increased with increasing the concentration of Sn. The Sn-doped samples showed PL with a broad feature due to the 5sp→5s2 transition of Sn2+. The PL decay constants were 4.72–4.83 μs, and any dependence on the concentration of Sn was not observed. The glasses showed intense TSL, and the glow curves had a broad feature peaking at 110 °C. Among the present samples, the 0.5% Sn-doped sample exhibited the highest sensitivity with a good linearity over 5 orders of magnitude (0.1–10000 mGy). In addition, the TSL fading characteristics were evaluated, and the integrated TSL intensities after two days were 5.5% (undoped), 41% (Sn:0.1%), 38% (Sn:0.2%), 40% (Sn:0.5%) and 35% (Sn:1.0%), respectively.

DOI

Photoluminescence and scintillation properties of Ce-doped Sr<inf>2</inf>(Gd<inf>1-x</inf>Lu<inf>x</inf>)<inf>8</inf>(SiO<inf>4</inf>)<inf>6</inf>O<inf>2</inf>(x = 0.1, 0.2, 0.4, 0.5, 0.6) crystals

Takuya Igashira, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Optical Materials ( Elsevier B.V. )  79   232 - 236   2018.05  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier B.V. Apatite crystals with chemical compositions of 0.5% Ce-doped Sr2(Gd1-xLux)8(SiO4)6O2(x = 0.1, 0.2, 0.4, 0.5, 0.6) were synthesized by the Floating Zone method, and then we evaluated their photoluminescence (PL) and scintillation properties. All the Ce-doped samples exhibited PL and scintillation with an intense broad emission in 400–550 nm in which the origin was attributed to the 5d-4f transition of Ce3+, and the emission peak became broader with increasing the concentration of Lu3+. Both PL and scintillation decay time profiles were best-approximated by a sum of two exponential decay functions, and the origin of slower component was attributed to the 5d-4f transition of Ce3+. In the X-ray induced afterglow measurements, the Ce-doped Sr2(Gd0.4Lu0.6)8(SiO4)6O2sample exhibited the lowest afterglow level. Furthermore, the Ce-doped Sr2(Gd0.5Lu0.5)8(SiO4)6O2and Sr2(Gd0.4Lu0.6)8(SiO4)6O2samples showed a clear full energy deposited peak under 5.5 MeV241Am α-ray irradiation, and the estimated absolute scintillation light yields were around 290 and 1300 ph/5.5 MeV-α respectively.

DOI

Dosimetric and scintillation properties of Ce-doped Li<inf>3</inf>PO<inf>4</inf>-B<inf>2</inf>O<inf>3</inf> glasses

Yuya Isokawa, Shotaro Hirano, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Journal of Non-Crystalline Solids ( Elsevier B.V. )  487   1 - 6   2018.05  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier B.V. In this study, we developed Li3PO4-B2O3 glasses doped with different concentrations (0, 0.1, 0.2, 0.5, and 1.0%) of Ce and studied the optical, dosimetric and scintillation properties. The Ce-doped samples showed scintillation and photoluminescence (PL) due to the 5d–4f transitions of Ce3+ with a broad spectral feature peaking around 350 nm. The scintillation and PL decay times were 55–62 ± 0.03 ns and 29–31 ± 0.03 ns, respectively. The PL quantum yield (QY) was about 15.3 ± 2% for the 0.1%-doped sample, and it decreased with increasing the concentration of Ce. The thermally-stimulated luminescence (TSL) was observed in all the samples after irradiating with X-rays, and the 0.1% Ce-doped sample showed the highest sensitivity with the dynamic range confirmed from 0.1 mGy to 10 Gy, which was equivalent to commercial detectors. Moreover, optically-stimulated luminescence (OSL) was observed in the 0.1%Ce-doped sample after X-ray irradiation. Overall, doping with Ce enhanced the PL, scintillation, TSL and OSL properties. The optimal concentration of Ce was 0.1% to be used for radiation detector applications.

DOI

Scintillation and thermoluminescence properties of Ce-doped Ca<inf>2</inf>Al<inf>2</inf>SiO<inf>7</inf> single crystals

Taiki Ogawa, Daisuke Nakauchi, Go Okada, Naoki Kawano, Noriaki Kawaguchi, Takayuki Yanagida

Journal of Luminescence   196   270 - 274   2018.04  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier B.V. Undoped and Ce-doped Ca2Al2SiO7 single crystals with different Ce concentrations were prepared by the floating zone method. From the X-ray diffraction patterns, we confirmed that all the grown crystals have no impurity phases. The undoped sample shows scintillation induced by X-rays, and the spectrum consists of two broad emission bands peaking at 350 and 400 nm. The decay curve appeared to consist of only single exponential decay with the decay constant of 51 ns. In contrast, Ce-doped samples show a broad scintillation peaking around 400 nm, in which the decay curve consists of two exponential decay functions with the decay times of approximately 30 and 100 ns. From the pulse height spectra measured using the present samples under 241Am 59.5 keV γ-ray irradiation, we confirmed that the 0.3% Ce-doped sample exhibits the highest absolute scintillation light yield of 16,000 ph/MeV. The samples also exhibit thermoluminescence (TL). The glow curves appear to have a broad feature with the peak temperature from 100 to 500 °C for undoped and from 50 to 400 °C for Ce-doped samples. Among the present samples, the 0.3% Ce-doped sample shows the highest sensitivity, and a linear response to the irradiation dose was confirmed in the dose range of 0.01–100 mGy.

DOI

Characterizations of Pr-doped Yb<inf>3</inf>Al<inf>5</inf>O<inf>12</inf> single crystals for scintillator applications

Yasuki Yoshida, Kenji Shinozaki, Takuya Igashira, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Solid State Sciences ( Elsevier Masson SAS )  78   1 - 6   2018.04  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 Elsevier Masson SAS Yb3Al5O12 (YbAG) single crystals doped with different concentrations of Pr were synthesized by the Floating Zone (FZ) method. Then, we evaluated their basic optical and scintillation properties. All the samples showed photoluminescence (PL) with two emission bands appeared approximately 300–500 nm and 550–600 nm due to the charge transfer luminescence of Yb3+ and intrinsic luminescence of the garnet structure, respectively. A PL decay profile of each sample was approximated by a sum of two exponential decay functions, and the obtained decay times were 1 ns and 3–4 ns. In the scintillation spectra, we observed emission peaks in the ranges from 300 to 400 nm and from 450 to 550 nm for all the samples. The origins of these emissions were attributed to charge transfer luminescence of Yb3+ and intrinsic luminescence of the garnet structure, respectively. The scintillation decay times became longer with increasing the Pr concentrations. Among the present samples, the 0.1% Pr-doped sample showed the lowest scintillation afterglow level. In addition, pulse height spectrum of 5.5 MeV α-rays was demonstrated using the Pr-doped YbAG, and we confirmed that all the samples showed a full energy deposited peak. Above all, the 0.1% Pr-doped sample showed the highest light yield with a value of 14 ph/MeV under α-rays excitation.

DOI

Comparative study of radiation-induced luminescence between non-doped CsBr transparent ceramic and crystal

Hiromi Kimura, Fumiya Nakamura, Takumi Kato, Daisuke Nakauchi, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Journal of the Ceramic Society of Japan   126 ( 3 ) 184 - 189   2018.03  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 The Ceramic Society of Japan. All rights reserved. We synthesized bulk CsBr samples in a transparent ceramic form by spark plasma sintering (SPS) and in a single crystal form by the vertical Bridgman-Stockbarger method, and investigated their optical, scintillation and dosimeter properties. In photoluminescence, scintillation, thermally-stimulated luminescence (TSL) and optically-stimulated luminescence (OSL), the CsBr in both the material forms showed broad emission peaks at around 450 nm, the origin of which was considered to be due to oxygen impurities. The TSL and OSL properties were notably enhanced in the transparent ceramic, in particular. The dosimetric sensitivities were confirmed to be as low as 0.01 mGy using TSL but were 1mGy using OSL for both the transparent ceramic and single crystal forms.

DOI

Comparative study of dosimeter properties of Eu-doped CsBr transparent ceramic and single crystal

Hiromi Kimura, Fumiya Nakamura, Takumi Kato, Daisuke Nakauchi, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Optik   157   421 - 428   2018.03  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier GmbH We have synthesized Eu-doped CsBr transparent ceramics by spark plasma sintering (SPS) and a single crystal by the vertical Bridgman-Stockbarger method. Subsequently, we have investigated their optical, scintillation and dosimeter properties. In scintillation, both the materials showed a broad emission peaking around 440 nm, and the origin was due to 4f65d1-4f7 transitions of Eu2+. In the optically-stimulated luminescence (OSL) properties, OSL intensity of the ceramic sample was higher than those of the crystal sample. The dosimetric sensitivities were confirmed as low as 0.01 mGy using TSL while 0.1 mGy using OSL for both of the ceramic and single crystal samples.

DOI

Scintillation, dosimeter and optical properties of MgF<inf>2</inf> transparent ceramics doped with Gd³⁺

Fumiya Nakamura, Takumi Kato, Go Okada, Naoki Kawano, Noriaki Kawaguchi, Kentaro Fukuda, Takayuki Yanagida

Materials Research Bulletin ( Elsevier Ltd )  98   83 - 88   2018.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier Ltd In this study, we have developed MgF2:Gd transparent ceramics by spark plasma sintering (SPS) and evaluated the scintillation, dosimeter and optical properties. All the sample were successfully synthesized in a transparent form with relative densities over 99% to that of the single crystal. The samples were confirmed to show scintillation, thermally-stimulated luminescence (TSL) and optically-stimulated luminescence (OSL). The origin of these emissions was due to the 4f-4f transitions of Gd3+ appearing as a single peak at 310 nm. In particular, the TSL was very sensitive to X-rays, and especially the 1% Gd-doped sample showed a sensitivity as low as 0.1 mGy. The TSL response increases monotonically with the irradiation dose, and the dynamic range was confirmed to be over 0.1–1000 mGy, which was equivalent sensitivity to that of commercial personal dosimeters.

DOI

Scintillation and dosimetric properties of Tb-doped LiCaAlF<inf>6</inf> single crystals

Noriaki Kawaguchi, Daisuke Nakauchi, Shotaro Hirano, Naoki Kawano, Go Okada, Kentaro Fukuda, Takayuki Yanagida

Japanese Journal of Applied Physics   57 ( 2 )   2018.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 The Japan Society of Applied Physics. We have investigated the scintillation and dosimetric properties of Tb-doped LiCaAlF6 single crystals. The X-ray-induced emission spectrum consisted of several sharp peaks due to the 4f-4f transitions of the Tb3+ ion. The thermoluminescence (TL) spectrum showed similar emission peaks as in those of the X-ray-induced luminescence. The TL intensity monotonically increased as a function of X-ray irradiation dose, and the dose response was demonstrated from 0.01 to 10 mGy. These results suggest that the Tb-doped LiCaAlF6 single crystal is a good candidate TL dosimeter material for low-dose applications.

DOI

Scintillation and dosimetric properties of Ce-doped strontium aluminoborate glasses

Naoki Kawano, Noriaki Kawaguchi, Go Okada, Yutaka Fujimoto, Takayuki Yanagida

Journal of Non-Crystalline Solids ( Elsevier B.V. )  482   154 - 159   2018.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier B.V. Strontium aluminoborate glasses with different concentrations of Ce (0, 0.01, 0.05, 0.1 and 0.5 mol%) were synthesized by the conventional melt-quenching technique. After the synthesis, photoluminescence (PL), scintillation and dosimetric properties of the samples were evaluated systematically. In the photoluminescence and scintillation spectra, a sharp peak around 370 nm due to the 5d-4f transitions of Ce was observed. The 0.05% Ce-doped sample showed the highest intensity in PL and scintillation among the samples investigated. The 0.01–0.1% Ce-doped samples also showed thermally-stimulated luminescence (TSL) with a glow peak of around 90 °C after X-ray irradiation. The TSL response of 0.01–0.05% Ce-doped samples increased monotonically with X-ray dose over a dose range of 10− 1–104 mGy.

DOI

Radioluminescence and photoluminescence properties of Dy-doped 12CaO 7Al<inf>2</inf>O<inf>3</inf> single crystals synthesized by the floating zone method

Narumi Kumamoto, Daisuke Nakauchi, Takumi Kato, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Japanese Journal of Applied Physics   57 ( 2 )   2018.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 The Japan Society of Applied Physics. We have synthesized Dy-doped 12CaO 7Al2O3 (Dy:C12A7) single crystals with various Dy concentrations by the floating zone (FZ) method and investigated the photoluminescence (PL) and X-ray induced radioluminescence (RL) properties. The PL emissions are observed around 480-490, 570-590, 650-690, and 750 nm due to the 4f-4f transitions of Dy3+ under excitation around 350-400 and 450 nm. The decay time constant (580 nm emission under 340-390 nm excitation) was approximately 0.54-0.58 ms. The RL also showed line emissions at 487, 580, 668, and 757 nm due to the 4f-4f transitions of Dy3+ while the decay time was approximately 0.49-0.53 ms.

DOI

Radiation-induced luminescence properties of Tb-doped Li<inf>3</inf>PO<inf>4</inf>-B<inf>2</inf>O<inf>3</inf> glasses

Yuya Isokawa, Shotaro Hirano, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Optical Materials ( Elsevier B.V. )  76   28 - 33   2018.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier B.V. In this study, we developed Li3PO4-B2O3 glasses doped with different concentrations of Tb (0.1, 0.3, 1.0, 3.0, and 10.0%) as well as undoped glass, and then the prepared glasses were studied for the optical, dosimeter and scintillator properties. The Tb-doped samples indicated radioluminescence and photoluminescence (PL) due to the 4f-4f transitions of Tb3+ with sharp spectral features peaking around 375, 410, 435, 480, 540, 590 and 620 nm. The luminescence decay times of radioluminescence and PL were 2.3–2.7 ms and 2.7–2.9 ms, respectively. The shorter radioluminescence decay time than that of PL indicated quenching effect of excited states in radioluminescence. As the concentration of Tb increased, both the radioluminescence intensity and PL quantum yield (QY) increased, and the 10.0% Tb-doped sample showed the highest radioluminescence intensity and QY (54.3%). In addition, thermally-stimulated luminescence (TSL) was observed after irradiating with X-rays. The sensitivity was the highest for the 3.0% Tb-doped sample having a dynamic range from 0.1 mGy to 10 Gy, which was equivalent to commercial dosimeters. The comprehensive studies suggested that X-ray generated charges are captured at TSL-active centers more effectively at lower concentrations of Tb whereas the recombination probability at Tb center during irradiation increases with the concentration of Tb. Consequently, the optimal Tb concentration was 10% as scintillator and 3.0% for TSL dosimeter, among the present samples.

DOI

Photoluminescence, scintillation and TSL properties of Ce-doped Sr(PO<inf>3</inf>)<inf>2</inf> glasses

Hayata Samizo, Takumi Kato, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Journal of Materials Science: Materials in Electronics ( Springer New York LLC )  29 ( 3 ) 1985 - 1991   2018.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017, Springer Science+Business Media, LLC. In this study, we have synthesized Sr(PO3)2 glasses non-doped and doped with Ce (0.01, 0.05, 0.1, 1.0 and 3.0 mol%) prepared by the conventional melt-quenching method and investigated the optical properties [transmittance spectra, photoluminescence (PL) spectra, PL excitation spectra and PL decay times], scintillation properties with X-rays (scintillation spectra, scintillation decay times) and thermally-stimulated luminescence (TSL) properties (glow curves and dose response functions). The PL spectrum of the Ce-doped samples consist of an intense emission band due to the 5d–4f transitions of Ce3+ ion peaking at 350 nm. The decay time of the corresponding emission was 32–37 ns depending on the Ce concentration. The samples also showed scintillation with X-ray having a spectrum of an intense emission band peaking at 350 nm due to the Ce3+ ions, and decay time was 34–217 ns. The TSL glow peaks were observed at 190 and 450 °C for the Ce-doped glasses, and the dynamic range was confirmed at least over a three orders of magnitude 100–103 mGy.

DOI

Optical and radioluminescence properties of Ce-doped Sr<inf>2</inf>RE<inf>8</inf>(SiO<inf>4</inf>)<inf>6</inf>O<inf>2</inf> (RE = Y, Gd, Lu)

Takuya Igashira, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Optik ( Elsevier GmbH )  155   36 - 42   2018.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier GmbH Ce-doped Sr2Y8(SiO4)6O2, Sr2Gd8(SiO4)6O2 and Sr2Lu8(SiO4)6O2 (SrYS, SrGS and SrLuS, respectively) apatite crystals were grown by the Floating Zone method, and their optical and radioluminescence (RL) properties were characterized. In the photoluminescence (PL) and RL spectra, we observed an emission band between 400 and 500 nm for all the samples, which were due to the 5d-4f transition of Ce3+. The RL decay time profiles were approximated by a sum of two exponential decay functions, and the origin of faster decay component was due to the 5d-4f transition of Ce3+. Among all the samples, SrGS sample showed the lowest afterglow level. In the pulse height spectrum, all the samples showed a full energy absorption peak under 241Am 5.5 MeV α-ray irradiation. The absolute scintillation light yields of SrYS, SrGS and SrLuS were around 31, 76 and 940 ph/5.5 MeV-α respectively.

DOI

Luminescence properties of organic-inorganic layered perovskite-type compounds under vacuum ultraviolet irradiation

Naoki Kawano, Masanori Koshimizu, Go Okada, Yutaka Fujimoto, Noriaki Kawaguchi, Takayuki Yanagida, Keisuke Asai

Japanese Journal of Applied Physics ( Japan Society of Applied Physics )  57 ( 2 )   2018.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 The Japan Society of Applied Physics. We investigated the luminescence properties of organic-inorganic layered perovskite-type compounds under vacuum ultraviolet irradiation. A crystal of (C6H5C2H4NH3)2PbBr4 was fabricated by the poor-solvent diffusion method. Exciton emissions from the inorganic layer were observed at 410 nm under ultraviolet irradiation (excitation wavelengths: 180 and 300 nm). The rise time behavior observed in the luminescence decay curve showed no difference among the excitation wavelengths of 60-300 nm. In addition, no excitation peak of benzene such as an intense peak at 180 nm (1A1g → 1E1u) in the vacuum ultraviolet region was observed in the excitation spectra measured while monitoring the exciton emissions from the inorganic layer. These results indicate that the effect of energy transfer from the organic layer to the inorganic layer has negligible contribution to the luminescence properties of organic-inorganic layered perovskite-type compounds.

DOI

Effects of Ga substitution in Ce:Tb<inf>3</inf>Ga <inf>x</inf> Al<inf>5-</inf><inf>x</inf> O<inf>12</inf> single crystals for scintillator applications

Daisuke Nakauchi, Go Okada, Naoki Kawano, Noriaki Kawaguchi, Takayuki Yanagida

Japanese Journal of Applied Physics   57 ( 2 )   2018.02  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 The Japan Society of Applied Physics. Bulk single crystals of Ce-doped Tb3Ga x Al5-x O12 (x = 0-4) were successfully synthesized by the floating zone method. The samples exhibit photoluminescence and scintillation with an intense broad emission due to the 5d-4f transitions of Ce3+ peaking around 550 nm as well as a few sharp peaks due to the 4f-4f transitions of Tb3+. Pulse height spectrum measurements under 137Cs γ-ray irradiation demonstrated a clear photoabsorption peak, in which the scintillation light yields were estimated to be 57,000 (x = 0), 28,000 (x = 1), 19,000 (x = 2), and 10,000 (x = 3) photons/MeV. Afterglow level can be suppressed with an appropriate addition of Ga, in which the optimum concertation is x = 2 leading an afterglow level of 23 ppm.

DOI

Radio-photoluminescence in non-doped K<inf>2</inf>CO<inf>3</inf> ceramics

Fumiya Nakamura, Takumi Kato, Go Okada, Naoki Kawano, Noriaki Kawaguchi, Takayuki Yanagida

Materials Letters ( ELSEVIER SCIENCE BV )  211   100 - 102   2018.01  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier B.V. In this letter, we report a discovery of a new radio-photoluminescence (RPL) material. The RPL appeared in vacuum-sintered non-doped K2CO3 ceramics as an evolution of PL emission band peaking at 440 nm. The RPL signal was confirmed to be sensitive to X-rays and stable at room temperature. The RPL response was observed as low as 1 mGy although the sample was not optimized. We strongly believe that this material should be a promising candidate as RPL dosimeter materials.

DOI

Scintillating organic-inorganic layered perovskite-Type compounds and the gamma-ray detection capabilities

Naoki Kawano, Masanori Koshimizu, Go Okada, Yutaka Fujimoto, Noriaki Kawaguchi, Takayuki Yanagida, Keisuke Asai

Scientific Reports ( NATURE PUBLISHING GROUP )  7 ( 1 )   2017.12  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 The Author(s). We investigated scintillation properties of organic-inorganic layered perovskite-Type compounds under gamma-ray and X-ray irradiation. A crystal of the hybrid compounds with phenethyl amine (17 × 23 × 4 mm) was successfully fabricated by the poor-solvent diffusion method. The bulk sample showed superior scintillation properties with notably high light yield (14,000 photons per MeV) under gamma-rays and very fast decay time (11 ns). The light yield was about 1.4 time higher than that of common inorganic material (GSO:Ce) confirmed under 137Cs and 57Co gamma-rays. In fact, the scintillation light yield was the highest among the organic-inorganic hybrid scintillators. Moreover, it is suggested that the light yield of the crystal was proportional with the gamma-ray energy across 122-662 keV. In addition, the scintillation from the crystal had a lifetime of 11 ns which was much faster than that of GSO:Ce (48 ns) under X-ray irradiation. These results suggest that organic-inorganic layered perovskite-Type compounds are promising scintillator for gamma-ray detection.

DOI PubMed

Optical and scintillation properties of Ce-doped Sr<inf>2</inf>Gd<inf>8</inf>(SiO<inf>4</inf>)<inf>6</inf>O<inf>2</inf> apatite single crystals

Takuya Igashira, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Journal of Materials Science: Materials in Electronics ( SPRINGER )  28 ( 24 ) 18630 - 18636   2017.12  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017, Springer Science+Business Media, LLC. We synthesized Sr2Gd8(SiO4)6O2 apatite single crystals with different Ce concentrations by the Floating Zone (FZ) method and evaluated the optical and scintillation properties. We confirmed photoluminescence (PL) and scintillation emissions appearing around 400 nm, which was attributed to the 5d-4f transitions of Ce3+. The PL decay curves were approximated by a sum of two exponential decay functions with the decay constants of 21–24 ns and 78–644 ns, which are due to the host emission and emission by the 5d-4f transition of Ce3+, respectively. The scintillation decays are notably longer than those of PL, and the decay constants decreased with increasing the concentration of Ce. The X-ray induced afterglow was the lowest in the 0.5% Ce-doped sample. The 0.5, 1.6 and 2.1% Ce-doped samples showed a full-energy peak in the pulse height spectrum under 241Am 5.5 MeV α-ray irradiation. Among those samples, 0.5% Ce-doped sample showed the highest scintillation light yield of 76 ph/5.5 MeV-α.

DOI

Comparative study of dosimeter properties between Al<inf>2</inf>O<inf>3</inf> transparent ceramic and single crystal

Takumi Kato, Naoki Kawano, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Radiation Measurements ( PERGAMON-ELSEVIER SCIENCE LTD )  107   43 - 47   2017.12  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 We have synthesized the Al2O3 transparent ceramic by using spark plasma sintering (SPS) and investigated the dosimeter and scintillation properties for X-ray detections, in comparison with the single crystal. Under X-ray irradiation, emissions at 300, 400 and 693 nm were observed in both the samples. To identify the origins of these emissions, scintillation decay times were investigated. Based on the results, emissions at 300, 400 and 693 nm are attributed to F+ centers, F centers and Cr3+ impurity ions, respectively. The thermally-stimulated luminescence (TSL) glow curves of both the samples showed a main peak around 50 °C. In addition, glow peaks were observed at 190, 290 and 360 °C. The TSL spectra had broad emission bands in the 300, 400 and 693 nm, which approximately agreed with the scintillation spectra. The TSL response was confirmed to be linear to the irradiation dose for transparent ceramic over the dose range from 0.3 to 1000 mGy while the sensitivity of the single crystal was lower and the response range confirmed was from 30 to 1000 mGy.

DOI

Optical, scintillation and dosimeter properties of MgO:Tb translucent ceramics synthesized by the SPS method

Naoki Kawano, Takumi Kato, Go Okada, Noriaki Kawaguchi, Takayuki Yanagida

Optical Materials ( ELSEVIER SCIENCE BV )  73   364 - 370   2017.11  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier B.V. MgO translucent ceramics doped with different concentrations of Tb (0.01, 0.05, 0.1, 0.5%) were prepared by the Spark Plasma Sintering (SPS) method. Further, the optical, scintillation, dosimeter properties of were evaluated systematically. In the photoluminescence (PL) and scintillation spectra, sharp emission peaks due to the 4f-4f transitions of Tb3+ were observed. In the PL and scintillation decay curves, the decay time constants were a few ms which were on a typical order of the 4f-4f transitions of Tb3+. The thermally-stimulated luminescence (TSL) glow curves exhibited glow peaks around 80, 160 °C after X ray irradiation of 10 mGy. The intensity of TSL peak at 160 °C exhibited a linear response against X-ray dose over a dose range of 0.1–10 mGy. The optically-stimulated luminescence (OSL) under 590 nm stimulation exhibited strong emissions due to Tb3+ around 385–550 nm after X-ray irradiation. As in TSL, the intensity of OSL peak showed a linear response to X-ray dose, and the dynamic range confirmed was 0.1–1000 mGy.

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Optical and scintillation properties of ScAlMgO<inf>4</inf> crystal grown by the floating zone method

Takayuki Yanagida, Masanori Koshimizu, Naoki Kawano, Go Okada, Noriaki Kawaguchi

Materials Research Bulletin ( PERGAMON-ELSEVIER SCIENCE LTD )  95   409 - 413   2017.11  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier Ltd The undoped ScAlMgO4 crystal was synthesized by the Floating Zone (FZ) method, and we evaluated the optical and scintillation properties. The transmittance spectrum showed the absorption edge around 200 nm. VUV-excited emission/excitation spectrum was characterized at a synchrotron facility (UVSOR). Our experiment revealed that the emission was around 400 nm by 200 nm excitation, and the excitation band was 170–210 nm for the latter emission peak. The decay time characterized by 280 nm excitation was 8.3 and 43 ns. Under X-ray irradiation, an emission was observed around 400 nm as for VUV excitation, and the latter decay time constants were 0.23 and 2.2 μs. In addition, the afterglow level at 20 ms after X-ray irradiation was around 0.1% of the intensity during irradiation.

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Optical and radiation-induced luminescence properties of Ce-doped magnesium aluminoborate glasses

Daisuke Nakauchi, Go Okada, Yutaka Fujimoto, Naoki Kawano, Noriaki Kawaguchi, Takayuki Yanagida

Optical Materials   72   190 - 194   2017.10  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier B.V. Optical, radioluminescence (RL) and thermoluminescence (TL) properties of magnesium aluminoborate glasses were evaluated. The samples were synthesized by the conventional melt-quenching technique using an alumina crucible under ambient atmosphere. After polishing, all the samples show good transparency. In photoluminescence, RL and TL, the emission is predominantly due to the 5d-4f transitions of Ce3+ appearing as a broad feature peaking around 300–500 nm, and the decay time constants are affected by concentration quenching but on the typical range for the 5d-4f transitions of Ce3+. TL glow curves are characterized as a single but broad glow peak over 100–300 °C, and the TL intensity monotonically increases with the X-ray dose irradiated over 1–10000 mGy.

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Comparative studies of optical and scintillation properties between LiGaO<inf>2</inf> and LiAlO<inf>2</inf> crystals

Takayuki Yanagida, Yutaka Fujimoto, Masanori Koshimizu, Naoki Kawano, Go Okada, Noriaki Kawaguchi

Journal of the Physical Society of Japan ( PHYSICAL SOC JAPAN )  86 ( 9 )   2017.09  [Refereed]

Research paper (journal)   Domestic Co-author

©2017 The Physical Society of Japan. We have investigated optical and scintillation properties of LiGaO2 and LiAlO2 crystals. From the transmittance spectra, the absorption edges were found to be around 200 nm but wider band gap was confirmed for LiAlO2 than LiGaO2. Both photoluminescence and scintillation spectra showed a broad emission band peaking at 340 nm in the both crystals. The scintillation decay times of LiGaO2 were 460 ns and 2.8 µs while that of LiAlO2 was 2 µs. Under neutron irradiation from 252Cf, the absolute scintillation light yields of LiGaO2 and LiAlO2 were 3300 ± 300 and 7200 ± 700 ph/n, respectively.

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Scintillation properties of TGG and TSAG crystals for imaging applications

Takayuki Yanagida, Go Okada, Takahiro Kojima, Takeshi Hayashi, Jisaburou Ushizawa, Naoki Kawano, Noriaki Kawaguchi

Physica B: Condensed Matter ( ELSEVIER SCIENCE BV )  518   51 - 55   2017.08  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 Elsevier B.V. Optical and scintillation properties of TGG (Tb3Ga5O12) and TSAG (Tb3Sc2Al3O12) crystals were investigated, and capabilities to be used as a scintillator screen were demonstrated. In photoluminescence (PL) spectra, some emission lines due to Tb3+4f-4f transitions appeared from 500 to 700 nm. PL quantum yields of TGG and TSAG were 6.5% and 50.9%, respectively. When irradiated by X-rays, these crystals showed intense scintillation, and the emission wavelengths were the same as those in PL spectra. The scintillation decay times of TGG and TSAG were 94 and 678 μs, respectively. Further, we have demonstrated X-ray imaging using both TSGG and TSAG crystal plates and confirmed a capability as scintillator screens.

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Luminescent and scintillation properties of Ce-doped Tb<inf>3</inf>Al<inf>5</inf>O<inf>12</inf> crystal grown from Al-rich composition

Daisuke Nakauchi, Go Okada, Naoki Kawano, Noriaki Kawaguchi, Takayuki Yanagida

Applied Physics Express   10 ( 7 )   2017.07  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 The Japan Society of Applied Physics. A Ce-doped Tb3Al5O12 single crystal was successfully synthesized via the floating zone method in an Al-rich composition. In both photoluminescence and scintillation, the emissions were predominantly due to the 5d-4f transitions of Ce3+ peaking around 550 nm, but emissions due to defects and the 4f-4f transitions of Tb3+ were revealed by the time-resolved analyses. The crystal quality and luminescence intensity were sufficiently high such that the crystal was applicable for pulse-height spectrum measurement. Under 137Cs γ-ray exposure, a clear photoabsorption peak was observed, and the estimated light yield was 57,000 photons/MeV.

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Eu-doped Ca<inf>2</inf>SiO<inf>4</inf> as a new radio-photoluminescence phosphor

Shota Asada, Go Okada, Takumi Kato, Fumiya Nakamura, Naoki Kawano, Noriaki Kawaguchi, Takayuki Yanagida

Chemistry Letters ( Chemical Society of Japan )  47 ( 1 ) 59 - 61   2017.06  [Refereed]

Research paper (journal)   Domestic Co-author

© 2018 The Chemical Society of Japan. Eu-doped Ca2SiO4 ceramics have been newly found to show radio-photoluminescence (RPL). An as-prepared material shows photoluminescence (PL) only due to Eu3+ whereas an additional broad emission due to Eu2+ appears in the red region as a result of RPL after X-ray irradiation. The RPL is attributed to the intravalence conversion of the Eu ion (Eu3+ ¼ Eu2+), and this response can be detected as low as 10 mGy of X-ray dose.

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Non-doped Na<inf>2</inf>CO<inf>3</inf> ceramics as a new radio-photoluminescence (RPL) material

Fumiya Nakamura, Takumi Kato, Daisuke Nakauchi, Go Okada, Naoki Kawano, Noriaki Kawaguchi, Takayuki Yanagida

Chemistry Letters   46 ( 9 ) 1383 - 1385   2017  [Refereed]

Research paper (journal)   Domestic Co-author

© 2017 The Chemical Society of Japan. In this letter, we report a new radio-photoluminescence (RPL) material. RPL is a phenomenon that new luminescent centers are generated by ionizing radiations. Sintered Na2CO3 ceramics in a vacuum showed PL band peaking around 430 nm under 340 ± 40 nm excitation in which the intensity increases by X-ray irradiation. This evolution indicates a generation of a luminescent center by irradiation, a clear evidence of RPL. The majority of existing RPL materials are typically doped with luminescent ions; however, the present material was not intentionally doped. The RPL signal was observed as low as 0.1 mGy, which is an equivalent sensitivity of a commercial RPL dosimeter. For these reasons, the Na2CO3 ceramic is a promising candidate for RPL dosimeters.

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Luminescence and scintillation properties of LiF:W single crystal for thermal-neutron detection

Noriaki Kawaguchi, Naoki Kawano, Go Okada, Takayuki Yanagida

Sensors and Materials ( MYU, SCIENTIFIC PUBLISHING DIVISION )  29 ( 10 ) 1431 - 1438   2017  [Refereed]

Research paper (journal)   Domestic Co-author

© MYU K.K. The luminescence and scintillation properties of LiF:W were investigated in comparison with those of LiCaAlF6:Eu and GS20 (Ce-doped lithium silicate glass). LiF:W showed photoluminescence and scintillation emission peaking at the wavelength of 440 nm with the decay time of approximately 43 μs, which was shorter than those of LiCaAlF6:Eu and GS20. The light yield of LiF:W estimated by pulse height spectroscopy was approximately 90 photons/neutron.

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