Radio-photoluminescence （RPL） is a phenomenon seen in luminescent materials in which the appearance of new photolu- minescence （PL） emission is induced by an incident ionizing radiation such as X-rays; and the sig...Radio-photoluminescence （RPL） is a phenomenon seen in luminescent materials in which the appearance of new photolu- minescence （PL） emission is induced by an incident ionizing radiation such as X-rays; and the signal is stable even after the irradia- tion and during the PL measurement. Since the induced PL intensity is proportional to the irradiation dose, the RPL can be used in ra- diation measurements. The distinct advantage of RPL over the conventional thermally- or photo-stimulated luminescence （abbrevi- ated as TSL or PSL） dosimeters is the stability of response signal. With an RPL detector, it allows us to readout the signal multiple time without signal fading. In this work, we discovered that CsBr：Sm showed an RPL phenomenon by X-ray irradiation, and we characterized this new material as an RPL detector. While the sample showed PL emissions mainly in the visible range, after an X-ray irradiation additional emissions could be observed in the red to near-infrared range around 650-850 nm and 900-1000 nm and longer. The RPL response was fairly stable overall, but very interestingly the 650-850 nm signal slightly increased while the 900-1000 nm decreased during PL readout. The dynamic range was confirmed over 1-104 mGy with linear response.展开更多
We investigated photoluminescence （PL） and scintillation properties of Ce3＋-doped Y3A12Ga3OI2 （Ce：YAGG） trans- parent ceramics synthesized by vacuum sintering with different Ce3＋ concentrations （mol.%） from 0...We investigated photoluminescence （PL） and scintillation properties of Ce3＋-doped Y3A12Ga3OI2 （Ce：YAGG） trans- parent ceramics synthesized by vacuum sintering with different Ce3＋ concentrations （mol.%） from 0.3% to 1% （0.3%Ce：YAGG, 0.5%Ce：YAGG, 0.8%Ce：YAGG and I%Ce：YAGG）. The samples were synthesized by the vacuum sintering technique. The obtained samples showed a very strong and broad PL emission by the 5dl-4f transition of Ce3＋ in the wavelength range from 470 to 600 nm. The PL decay profiles were approximated by a single exponential decay function with the time constants of around 33-39 ns, Fur- thermore, the scintillation spectra induced by X-rays showed similar features with those observed in PL. The scintillation decay time profiles followed a second-order exponential decay function. The fast component group （ranged 3542 ns） were dominantly contrib- uted by the 5d1-4f transition of Ce3＋. The pulse height spectra utilizing the latter emissions showed a clear photoabsorption peak. Among those samples tested, 0.5%Ce：YAGG sample showed the highest scintillation light yield of 21,400 ph/MeV under 13VCs y-ray irradiation.展开更多
Nd-doped SrA1204 （Nd：SrA1204） crystals were prepared by a floating zone （FZ） method with different dopant concentra- tions. The photoluminescence （PL） measurements under visible light excitations confirmed stro...Nd-doped SrA1204 （Nd：SrA1204） crystals were prepared by a floating zone （FZ） method with different dopant concentra- tions. The photoluminescence （PL） measurements under visible light excitations confirmed strong near infrared （NIR） emissions around 890 nm, which is due to the 4f-4f transitions of Nd3＋, and the decay time constants were 300-400 μs. Furthermore, VUV ex- citations revealed two broad emissions around 250450 and 500-700 run, which were attributed to self-trapped excitons （STEs） perturbed by Nd3＋. Moreover, the X-ray induced scintillation spectra showed some small peaks at around 380 nm in addition to NIR emissions at 1064 nm similarly seen in PL. The former scintillation decay time constants were 30-40 Its. In the undoped sample, these emissions mentioned above were not present but a weak broad emission around 450 nm appeared. In thermally stimulated lu- minescence （TSL） after X-ray irradiation, strong TSL glow peaks were observed in the Nd-doped samples at around 100 and 250 ℃.展开更多
Tb-doped 12CaO·7Al_2O_3（Tb：C12A7） crystals were synthesized by the floating zone（FZ） method and the photoluminescence（PL）, scintillation and thermally-stimulated luminescence（TSL） properties were investi...Tb-doped 12CaO·7Al_2O_3（Tb：C12A7） crystals were synthesized by the floating zone（FZ） method and the photoluminescence（PL）, scintillation and thermally-stimulated luminescence（TSL） properties were investigated. The photoluminescence（PL） emission spectra and PL decay time profiles were investigated by using Quantaurus-tau（Hamamatsu）. The scintillation spectra and decay time profiles were measured by using our laboratory-constructed set-up under X-ray irradiation. Finally, TSL glow curve was measured by using Nanogray TL-2000 with the heating rate of 1 °C/s. In PL and scintillation, emission peaks were observed at 493, 543, 587 and 620 nm due to the 4f-4f transitions of Tb3~＋. Decay time constants of the emission by PL and scintillation appeared to be different, and the measured values were approximately 2.4 and 1.9 ms, respectively. After X-ray irradiations, the 0.5%（all Tb contents in this paper are in mole fraction） and 1.0% Tb-doped samples showed a single intense and broad glow peak around 100 oC while 1.2%–1.5% Tb-doped samples showed notable additional peak around 250 oC.展开更多
(GdCa)(SiO)Oapatite crystals doped with different concentrations of Ce were synthesized by the Floating Zone(FZ) method, and we have evaluated the photoluminescence(PL) and radio luminescence(RL) properties. In PL, an...(GdCa)(SiO)Oapatite crystals doped with different concentrations of Ce were synthesized by the Floating Zone(FZ) method, and we have evaluated the photoluminescence(PL) and radio luminescence(RL) properties. In PL, an emission band appeared around 400 nm under excitation at 300 nm due to the5 d-4 f transitions of Ce3+. The PL decay curves were approximated by a second-order exponential decay function, and the derived decay time constants ranged around 20-25 ns and 40-480 ns. Similar emission was observed in RL, but the decay time constants were much longer than those in PL. The RL afterglow was the lowest in the 1.0% Ce-doped sample. The 1.0% and 2.0% Ce-doped samples showed a full-energy peak in the pulse height spectrum measured underAm 5.5 MeV α-ray irradiation, and the absolute scintillation light yields were estimated to be around 55 and 36 ph/5.5 MeV-a, respectively.展开更多
基金Project supported by a Grant-in-Aid for Scientific Research(A)(26249147)Grant-in-Aid for Research Activity Start-up(15H06409)+3 种基金Green Photonics Research from the Ministry of Education,Culture,Sports,Science and Technology of the Japanese Government(MEXT)the Adaptable and Seamless Technology Transfer Program(A-STEP)by the Japan Science and Technology(JST)Agencythe Murata Science Foundationa Cooperative Research Project of the Research Institute of Electronics,Shizuoka University
文摘Radio-photoluminescence （RPL） is a phenomenon seen in luminescent materials in which the appearance of new photolu- minescence （PL） emission is induced by an incident ionizing radiation such as X-rays; and the signal is stable even after the irradia- tion and during the PL measurement. Since the induced PL intensity is proportional to the irradiation dose, the RPL can be used in ra- diation measurements. The distinct advantage of RPL over the conventional thermally- or photo-stimulated luminescence （abbrevi- ated as TSL or PSL） dosimeters is the stability of response signal. With an RPL detector, it allows us to readout the signal multiple time without signal fading. In this work, we discovered that CsBr：Sm showed an RPL phenomenon by X-ray irradiation, and we characterized this new material as an RPL detector. While the sample showed PL emissions mainly in the visible range, after an X-ray irradiation additional emissions could be observed in the red to near-infrared range around 650-850 nm and 900-1000 nm and longer. The RPL response was fairly stable overall, but very interestingly the 650-850 nm signal slightly increased while the 900-1000 nm decreased during PL readout. The dynamic range was confirmed over 1-104 mGy with linear response.
文摘We investigated photoluminescence （PL） and scintillation properties of Ce3＋-doped Y3A12Ga3OI2 （Ce：YAGG） trans- parent ceramics synthesized by vacuum sintering with different Ce3＋ concentrations （mol.%） from 0.3% to 1% （0.3%Ce：YAGG, 0.5%Ce：YAGG, 0.8%Ce：YAGG and I%Ce：YAGG）. The samples were synthesized by the vacuum sintering technique. The obtained samples showed a very strong and broad PL emission by the 5dl-4f transition of Ce3＋ in the wavelength range from 470 to 600 nm. The PL decay profiles were approximated by a single exponential decay function with the time constants of around 33-39 ns, Fur- thermore, the scintillation spectra induced by X-rays showed similar features with those observed in PL. The scintillation decay time profiles followed a second-order exponential decay function. The fast component group （ranged 3542 ns） were dominantly contrib- uted by the 5d1-4f transition of Ce3＋. The pulse height spectra utilizing the latter emissions showed a clear photoabsorption peak. Among those samples tested, 0.5%Ce：YAGG sample showed the highest scintillation light yield of 21,400 ph/MeV under 13VCs y-ray irradiation.
基金Project supported by the Aid for Scientific Research((A)-26249147)from the Ministry of Education,Culture,Sports,Science and Technology of the Japanese government(MEXT)JST A-step,Green Photonics Research from MEXT+2 种基金the Adaptable and Seamless Technology Transfer Program(A-STEP)by the Japan Science and Technology(JST)Agencythe Murata Science Foundationa cooperative research project of the Research Institute of Electronics,Shizuoka University
文摘Nd-doped SrA1204 （Nd：SrA1204） crystals were prepared by a floating zone （FZ） method with different dopant concentra- tions. The photoluminescence （PL） measurements under visible light excitations confirmed strong near infrared （NIR） emissions around 890 nm, which is due to the 4f-4f transitions of Nd3＋, and the decay time constants were 300-400 μs. Furthermore, VUV ex- citations revealed two broad emissions around 250450 and 500-700 run, which were attributed to self-trapped excitons （STEs） perturbed by Nd3＋. Moreover, the X-ray induced scintillation spectra showed some small peaks at around 380 nm in addition to NIR emissions at 1064 nm similarly seen in PL. The former scintillation decay time constants were 30-40 Its. In the undoped sample, these emissions mentioned above were not present but a weak broad emission around 450 nm appeared. In thermally stimulated lu- minescence （TSL） after X-ray irradiation, strong TSL glow peaks were observed in the Nd-doped samples at around 100 and 250 ℃.
基金supported by a Grant-in-Aid for Scientific Research(A)26249147 from the Ministry of Education,Culture,Sports,Science and Technology of Japan(MEXT),JST A-step,Cooperative Research Project of Research Institute of Electronics,Shizuoka University,Inamori foundation,KRF foundation
文摘Tb-doped 12CaO·7Al_2O_3（Tb：C12A7） crystals were synthesized by the floating zone（FZ） method and the photoluminescence（PL）, scintillation and thermally-stimulated luminescence（TSL） properties were investigated. The photoluminescence（PL） emission spectra and PL decay time profiles were investigated by using Quantaurus-tau（Hamamatsu）. The scintillation spectra and decay time profiles were measured by using our laboratory-constructed set-up under X-ray irradiation. Finally, TSL glow curve was measured by using Nanogray TL-2000 with the heating rate of 1 °C/s. In PL and scintillation, emission peaks were observed at 493, 543, 587 and 620 nm due to the 4f-4f transitions of Tb3~＋. Decay time constants of the emission by PL and scintillation appeared to be different, and the measured values were approximately 2.4 and 1.9 ms, respectively. After X-ray irradiations, the 0.5%（all Tb contents in this paper are in mole fraction） and 1.0% Tb-doped samples showed a single intense and broad glow peak around 100 oC while 1.2%–1.5% Tb-doped samples showed notable additional peak around 250 oC.
基金Project supported by a Grant-in-Aid for Scientific Research(A) 26249147 from the Ministry of Education,Culture,Sports,Science and Technology of Japan(MEXT)JST A-step,Cooperative Research Project of Research Institute of Electronics,Shizuoka University+1 种基金Inamori FoundationKRF Foundation
文摘(GdCa)(SiO)Oapatite crystals doped with different concentrations of Ce were synthesized by the Floating Zone(FZ) method, and we have evaluated the photoluminescence(PL) and radio luminescence(RL) properties. In PL, an emission band appeared around 400 nm under excitation at 300 nm due to the5 d-4 f transitions of Ce3+. The PL decay curves were approximated by a second-order exponential decay function, and the derived decay time constants ranged around 20-25 ns and 40-480 ns. Similar emission was observed in RL, but the decay time constants were much longer than those in PL. The RL afterglow was the lowest in the 1.0% Ce-doped sample. The 1.0% and 2.0% Ce-doped samples showed a full-energy peak in the pulse height spectrum measured underAm 5.5 MeV α-ray irradiation, and the absolute scintillation light yields were estimated to be around 55 and 36 ph/5.5 MeV-a, respectively.
