Tatebayashi Gunma, Japan
Tatebayashi Gunma, Japan

Time filter

Source Type

Totsuka D.,Tohoku University | Totsuka D.,Nihon Kessho Kogaku Co. | Yanagida T.,NICHE | Fukuda K.,Tokuyama Corporation | And 6 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2011

Thermal neutron imaging using Si PIN photodiode line scanner and Eu-doped LiCaAlF6 crystal scintillator has been developed. The pixel dimensions of photodiode are 1.18 mm (width)×3.8 mm (length) with 0.4 mm gap and the module has 192 channels in linear array. The emission peaks of Eu-doped LiCaAlF6 after thermal neutron excitation are placed at 370 and 590 nm, and the corresponding photon sensitivities of photodiode are 0.04 and 0.34 A/W, respectively. Polished scintillator blocks with a size of 1.18 mm (width)×3.8 mm (length)×5.0 mm (thickness) were wrapped by several layers of Teflon tapes as a reflector and optically coupled to the photodiodes by silicone grease. JRR-3 MUSASI beam line emitting 13.5 meV thermal neutrons with the flux of 8×105 n/cm2+ s was used for the imaging test. As a subject for imaging, a Cd plate was moved at the speed of 50 mm/s perpendicular to the thermal neutron beam. Analog integration time was set to be 416.6 μs, then signals were converted by a deltasigma A/D converter. After the image processing, we successfully obtained moving Cd plate image under thermal neutron irradiation using PIN photodiode line scanner coupled with Eu-doped LiCaAlF6 scintillator. © 2011 Elsevier B.V. All rights reserved.


Sugiyama M.,Tohoku University | Fujimoto Y.,Tohoku University | Yanagida T.,NICHE | Totsuka D.,Tohoku University | And 4 more authors.
Optical Materials | Year: 2011

Using the micro-pulling-down (μ-PD) method, Tm-doped Lu 3Al5O12 (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. © 2011 Elsevier B.V. All rights reserved.


Patent
Nihon Kessho Kogaku Co. and Tohoku University | Date: 2012-08-17

An afterglow property of cesium iodide: thallium (CsI:Tl), in which CsI is a host material and doped with thallium, is improved. It is possible to improve the afterglow property of a scintillator by doping a crystal material including CsI (cesium iodide), as a host material, and thallium (Tl), as a luminescent center, with bismuth (Bi).


Patent
Tohoku University and Nihon Kessho Kogaku Co. | Date: 2014-06-25

An afterglow property of cesium iodide: thallium (CsI:Tl), in which CsI is a host material and doped with thallium, is improved. It is possible to improve the afterglow property of a scintillator by doping a crystal material including CsI (cesium iodide), as a host material, and thallium (Tl), as a luminescent center, with bismuth (Bi).


Patent
Nihon Kessho Kogaku Co. | Date: 2013-11-07

A fluorite having all the more excellent laser durability compared to a conventional fluorite is provided. A fluorite is proposed, in which the standard deviation of the surface areas of the Voronoi regions in a diagram from a Voronoi decomposition of the distribution of etch-pits in the (111) plane is 6,000 m^(2 )or less, or, in which the standard deviation of the distances of the Delaunay edges in a diagram from a Delaunay decomposition of the distribution of etch-pits of the (111) plane is 80 m or less.


Patent
Nihon Kessho Kogaku Co. | Date: 2011-06-30

A fluorite with excellent laser durability is provided by devising a heat-treatment method for CaF_(2 )crystal. A fluorite production method is proposed, wherein heat-treatment is carried out by providing, through compartment walls in the periphery of a fluorite crystal, a fluoride gas trap layer containing a fluoride gas-adsorbing material.


Patent
Nihon Kessho Kogaku Co. | Date: 2011-06-30

A fluorite having all the more excellent laser durability compared to a conventional fluorite is provided. A fluorite is proposed, in which the standard deviation of the surface areas of the Voronoi regions in a diagram from a Voronoi decomposition of the distribution of etch-pits in the (111) plane is 6,000 m^(2 )or less, or, in which the standard deviation of the distances of the Delaunay edges in a diagram from a Delaunay decomposition of the distribution of etch-pits of the (111) plane is 80 m or less.


Patent
Nihon Kessho Kogaku Co. | Date: 2014-03-19

A fluorite having all the more excellent laser durability compared to a conventional fluorite is provided. A fluorite is proposed, in which the standard deviation of the surface areas of the Voronoi regions in a diagram from a Voronoi decomposition of the distribution of etch-pits in the (111) plane is 6,000 m^(2) or less, or, in which the standard deviation of the distances of the Delaunay edges in a diagram from a Delaunay decomposition of the distribution of etch-pits of the (111) plane is 80 m or less.


Patent
Nihon Kessho Kogaku Co. | Date: 2013-05-29

A fluorite with excellent laser durability is provided by devising a heat-treatment method for CaF_(2) crystal. A fluorite production method is proposed, wherein heat-treatment is carried out by providing, through compartment walls in the periphery of a fluorite crystal, a fluoride gas trap layer containing a fluoride gas-adsorbing material.


Patent
Nihon Kessho Kogaku Co. | Date: 2013-07-03

A fluorite having all the more excellent laser durability compared to a conventional fluorite is provided. A fluorite is proposed, in which the standard deviation of the surface areas of the Voronoi regions in a diagram from a Voronoi decomposition of the distribution of etch-pits in the (111) plane is 6,000 m^(2) or less, or, in which the standard deviation of the distances of the Delaunay edges in a diagram from a Delaunay decomposition of the distribution of etch-pits of the (111) plane is 80 m or less.

Loading NIHON KESSHO KOGAKU Co. collaborators
Loading NIHON KESSHO KOGAKU Co. collaborators