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1.
Scintillation properties of Tm-doped Lu3Al5O12 single crystals 总被引:1,自引:0,他引:1
Makoto Sugiyama Yutaka Fujimoto Takayuki Yanagida Daisuke Totsuka Yuui Yokota Akira Yoshikawa 《Optical Materials》2011,34(2):439-443
Using the micro-pulling-down (μ-PD) method, Tm-doped Lu3Al5O12 (Tm:LuAG) single crystals were grown to examine their scintillation properties. In transmittance spectra, they exhibited about 80% transparency in the wavelengths longer than 320 nm and five absorption lines due to Tm3+ 4f–4f transitions were observed. 241Am α-ray excited radioluminescence spectra were measured and intense 4f–4f emission peaks were observed with the host emission. When excited by 137Cs γ-Ray to obtain pulse height spectra, Tm 1% doped LuAG showed the highest light yield coupled with a photomultiplier (PMT) or a silicon avalanche photodiode (Si-APD). The light yield was estimated to be 5800 and 7300 photons/MeV for PMT and Si-APD, respectively. Decay time profiles consist of two exponential components and the fast and slow components are considered to be attributed to the host and the combination of the host and Tm3+ 4f–4f emission, respectively. 相似文献
2.
Makoto Sugiyama Yutaka FujimotoTakayuki Yanagida Yuui YokotaJan Pejchal Yuki FuruyaHidehiko Tanaka Akira Yoshikawa 《Optical Materials》2011,33(6):905-908
Nd 0.1%, 0.5%, 1% and 3% doped Lu3Al5O12 (Nd:LuAG) single crystals were grown in the nitrogen atmosphere by the micro-pulling down (μ-PD) method. The grown crystals had a single-phase confirmed by powder XRD analysis. In absorption spectra, some weak absorption lines due to Nd3+ 4f-4f transitions were observed and their intensity increased with the increase of Nd concentration. When excited by 241Am α-ray, a broad emission peak due to defects in the host lattice at 320 nm and some sharp lines due to Nd3+ 4f-4f transitions at wavelength longer than 400 nm were observed. The decay time profiles of Nd:LuAG under γ-ray excitation were well approximated by two exponential function of 340-760 ns and 3-5 μs for each sample. By pulse height measurement using 137Cs, Nd 0.5%:LuAG showed the highest light yield of 7600 ± 760 photons/MeV. 相似文献
3.
Makoto Sugiyama Yutaka FujimotoTakayuki Yanagida Daisuke Totsuka Shunsuke KurosawaYoshisuke Futami Yuui YokotaValery Chani Akira Yoshikawa 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2012,664(1):127-131
Er-doped Lu3Al5O12 (Er:LuAG) single crystalline scintillators with different Er concentrations of 0.1, 0.5, 1, and 3% were grown by the micro-pulling-down (μ-PD) method. The grown crystals were composed of single-phase material, as demonstrated by powder X-ray diffraction (XRD). The radioluminescence spectra measured under 241Am α-ray excitation indicated host emission at approximately 350 nm and Er3+ 4f-4f emissions. According to the pulse height spectra recorded under γ-ray irradiation, the 0.5% Er:LuAG exhibited the highest peak channel among the samples. The γ-ray excited decay time profiles were well fitted by the two-component exponential approximation (0.8 μs and 6-10 μs). 相似文献
4.
Takayuki Yanagida Kentaro FukudaYutaka Fujimoto Noriaki Kawaguchi Shunsuke KurosawaAtsushi Yamazaki Kenichi WatanabeYoshisuke Futami Yuui YokotaJan Pejchal Akira Yoshikawa Akira UritaniTetsuo Iguchi 《Optical Materials》2012,34(5):868-871
Eu2+ 0.05%, 0.1%, and 0.2% activated LiF-SrF2 eutectic scintillators were prepared by the Bridgman method using 6Li enriched (95%) raw material. The α-ray-induced radio luminescence spectra showed intense emission peak at 430 nm due to an emission from Eu2+ 5d-4f transition in the Eu:SrF2 layers. When excited by 252Cf neutrons, all the samples exhibited almost the same light yields of 5000-7000 ph/n with a typical decay times of several hundreds ns. 相似文献
5.
Shingo Wakahara Yuki FuruyaTakayuki Yanagida Yuui YokotaJan Pejchal Makoto SugiyamaNoriaki Kawaguchi Daisuke Totsuka Akira Yoshikawa 《Optical Materials》2012,34(4):729-732
0.1%, 0.5%, 1% and 3% Ce doped scintillation crystals based on NaF-CaF2-LuF3 solid solutions were grown from the melt using Micro-Pulling-Down (μ-PD) method. The grown crystals were transparent and their transmittance was approximately 80% for the wavelengths longer than 320 nm. Concerning the scintillation properties, radio-luminescence peaks of the crystals were detected at approximately 330 nm. The light yield of the crystals was also measured using γ-ray (137Cs and 22Na) as the excitation source. 相似文献
6.
Noriaki Kawaguchi Takayuki YanagidaYutaka Fujimoto Yuui YokotaKei Kamada Kentaro FukudaToshihisa Suyama Kenichi WatanabeAtsushi Yamazaki Valery ChaniAkira Yoshikawa 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,652(1):351-354
Thermal neutron imaging with Ce-doped LiCaAlF6 crystals has been performed. The prototype of the neutron imager using a Ce-doped LiCaAlF6 scintillating crystal and a position sensitive photomultiplier tube (PSPMT) which had 64 multi-channel anode was developed. The Ce-doped LiCaAlF6 single crystal was grown by the Czochralski method. A plate with dimensions of a diameter of 50×2 mm2 was cut from the grown crystal, polished, and optically coupled to PSPMT by silicone grease. The 252Cf source (<1 MBq) was sealed with 43 mm of polyethylene for neutron thermalization. Alphabet-shaped Cd pieces with a thickness of 2 mm were used as a mask for the thermal neutrons. After corrections for the pedestals and gain of each pixel, we successfully obtained two-dimensional neutron images using Ce-doped LiCaAlF6. 相似文献
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8.
Daisuke Totsuka Takayuki Yanagida Makoto Sugiyama Yutaka Fujimoto Yuui Yokota Akira Yoshikawa 《Materials Research Bulletin》2012,47(4):993-997
In this work, we present results of structural characterization and optical properties including radio luminescence of (LuxGdyY0.99?x?yTm0.01)AP single crystal scintillators for (x, y) = (0.30, 0.19), (0, 0.19) and (0, 0) grown by the micro-pulling-down (μ-PD) method. The grown crystals were single phase materials with perovskite structure (Pbnm) as confirmed by XRD and had a good crystallinity. The distribution of the crystal constituents in growth direction was evaluated, and significant segregation of Lu and Gd was detected in (Lu0.30Gd0.19Y0.50Tm0.01)AP sample. The crystals demonstrated 70% transmittance in visible wavelength range and some absorption bands due to Tm3+, Gd3+ and color centers were exhibited in 190–900 nm. The radioluminescence measurement under X-ray irradiation demonstrated several emission peaks ascribed to 4f–4f transitions of Tm3+ and Gd3+. The ratio of emission intensity in longer wavelength range was increased when Y was replaced by Lu or Gd. 相似文献
9.
Yutaka Fujimoto Takayuki Yanagida Yuui Yokota Noriaki Kawaguchi Kentaro Fukuda Daisuke Totsuka Kenichi Watanabe Atsushi Yamazaki Akira Yoshikawa 《Optical Materials》2011,34(2):444-447
The undoped and 0.5% Ce3+-doped strontium metaborate SrB2O4 single crystals has been grown successfully by micro-pulling down method with radio frequency (RF) heating system, and scintillation characteristics including optical properties and radiation response were studied for these crystals. The Ce3+-doped SrB2O4 crystal showed absorption band around 240–320 nm, which is corresponding to the 4f-5d transition of Ce3+. Intense emission band at 375 nm due to the Ce3+ 5d–4f transition was observed under 241Am 5.5 MeV α-ray excitation. The scintillation decay time showed fast (50 ns) and slow (1430 ns) components ascribed to the Ce3+ 5d–4f transition and lattice defect in the crystal, respectively. The scintillation light yield of Ce3+-doped SrB2O4 was calculated to be about 1000 ph/n under 252Cf irradiation. 相似文献
10.
Kentaro Fukuda Noriaki Kawaguchi Sumito IshizuTomohito Nagami Toshihisa SuyamaTakayuki Yanagida Yuui YokotaMartin Nikl Akira Yoshikawa 《Optical Materials》2011,33(6):924-927
Sixty millimeter diameter single crystal of Nd3+ doped LiLuF4 was successfully grown by the Czochralski technique. No remarkable absorption due to unfavorable impurities was observed from optical absorption measurements in the vacuum ultra-violet spectral region. The high crystallinity and homogeneous luminescence characteristics were found from X-ray rocking curve and cathode-ray luminescence respectively. X-ray excited luminescence spectrum was measured and the significant 4f25d-4f3 luminescence at 182 nm was observed in the grown crystal. The pulse height spectrum was taken upon γ-ray irradiation. As a result, the grown crystals demonstrated sufficient response to the γ-ray showing the light yield of 420 ± 30 photons/MeV. The decay curve under α-ray irradiation was also investigated and described by two component decay kinetics which consists of the decay constants of 34 and 450 ns. 相似文献