Growth and scintillation properties of LiBr/CeBr3 eutectic scintillator for neutron detection

2021 ◽  
Author(s):  
Ryuga Yajima ◽  
Kei Kamada ◽  
Yui Takizawa ◽  
Masao Yoshino ◽  
Kyoung Jin Kim ◽  
...  
Keyword(s):  
Thermal Neutron ◽  
Gamma Ray ◽  
Neutron Detection ◽  
Eutectic Structure ◽  
Growth Direction ◽  
Emission Peak ◽  
Molar Ratio ◽  
X Ray ◽  
Vertical Bridgman ◽  
Lamellar Type

Abstract The 6LiBr/CeBr3 eutectic scintillator for thermal neutron detection has been developed due to achieving high 6Li concentration. The eutectics were grown by vertical Bridgman method. Molar ratio of 6Li in 6LiBr/CeBr3 eutectic is 35 %, which is higher than that of commercial neutron scintillators such Ce:LiCaAlF6 and Ce:Cs2LiYCl6. The grown eutectic had lamellar-type eutectic structure extending along the growth direction and optical transparency. The grown eutectics showed an emission peak at 360 and 380 nm ascribed to Ce3+ 4f-5d transition from CeBr3 scintillation phase. The measurements of scintillation performance of the 6LiBr/CeBr3 were performed using x-ray, gamma-ray and neutron irradiation to evaluate its potential as a neutron scintillator.

Hydrogen Permeation Properties of Nb-Based Two-Phase Compounds

2007 ◽  
Vol 561-565 ◽  
pp. 467-470
Author(s):  
Yuji Yamaguchi ◽  
Kyosuke Kishida ◽  
Katsushi Tanaka ◽  
Haruyuki Inui ◽  
Sho Tokui ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
Hydrogen Permeation ◽  
Membrane Surface ◽  
Hydrogen Permeability ◽  
Eutectic Structure ◽  
Growth Direction ◽  
Directionally Solidified ◽  
Two Phase ◽  
Cast Sample ◽  
Lamellar Type

Nb-NiTi and Nb-CoTi eutectic alloys were directionally solidified in an optical floating zone furnace. Rod-type eutectic structures with Nb rods aligned parallel to the growth direction are obtained for Nb-41Ni-40Ti grown at relatively slow growth rates below 1.0mm/h, while lamellar-type eutectic structures are obtained for Nb-35Co-34Ti grown at the same condition. The hydrogen permeability for the Nb-41Ni-40Ti DS alloy with Nb rods perpendicular to the membrane surface is 2.60×10-8mol H2 m-1 Pa-1/2 at 673K, which is about 2.5 times higher than that of as-cast sample. No hydrogen embrittlement is observed between 573 and 673K, indicating that the Nb-NiTi rod-type eutectic structure effectively suppresses the hydrogen embrittlement of Nb during hydrogen permeation.

scholarly journals Thin Film Polymer Composite Scintillators for Thermal Neutron Detection

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Andrew N. Mabe ◽  
John D. Auxier ◽  
Matthew J. Urffer ◽  
Stephen A. Young ◽  
Dayakar Penumadu ◽  
...  
Keyword(s):  
Thin Film ◽  
Thermal Neutron ◽  
Gamma Ray ◽  
Detection Efficiency ◽  
Fluorescence Emission ◽  
Neutron Detection ◽  
Fluorescent Sensors ◽  
Neutron Detectors ◽  
Neutron Detection Efficiency ◽  
Film Polymer

Thin film polystyrene composite scintillators containing LiF6 and organic fluors have been fabricated and tested as thermal neutron detectors. Varying fluorescence emission intensities for different compositions are interpreted in terms of the Beer-Lambert law and indicate that the sensitivity of fluorescent sensors can be improved by incorporating transparent particles with refractive index different than that of the polymer matrix. Compositions and thicknesses were varied to optimize the fluorescence and thermal neutron response and to reduce gamma-ray sensitivity. Neutron detection efficiency and neutron/gamma-ray discrimination are reported herein as functions of composition and thickness. Gamma-ray sensitivity is affected largely by changing thickness and unaffected by the amount of LiF6 in the film. The best neutron/gamma-ray discrimination characteristics are obtained for film thicknesses in the range 25–150 μm.

scholarly journals Improvement of CdMnTe Detector Performance by MnTe Purification

2011 ◽  
Vol 1341 ◽  
Author(s):  
K. H. Kim ◽  
A. E. Bolotnikov ◽  
G. S. Camarda ◽  
R. Tappero ◽  
A. Hossain ◽  
...  
Keyword(s):  
High Performance ◽  
Gamma Ray ◽  
Zone Refining ◽  
High Solubility ◽  
Detector Performance ◽  
X Ray ◽  
Gamma Ray Detectors ◽  
Refining Method ◽  
Vertical Bridgman ◽  
Very High

ABSTRACTResidual impurities in manganese (Mn) are a big obstacle to obtaining high- performance CdMnTe (CMT) X-ray and gamma-ray detectors. Generally, the zone-refining method is an effective way to improve the material’s purity. In this work, we purified the MnTe compounds combining the zone-refining method with molten Te that has a very high solubility. We confirmed the improved purity of the material by glow-discharge mass spectrometry (GDMS). We also found that CMT crystals from a multiple refined MnTe source, grown by the vertical Bridgman method, yielded better performing detectors.

scholarly journals The Influence of the Cooling Bores on Crystal Orientation and Lattice Parameter in Single-Crystalline Cored Turbine Blades

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3842
Author(s):  
Jacek Krawczyk ◽  
Włodzimierz Bogdanowicz ◽  
Jan Sieniawski
Keyword(s):  
Solidification Front ◽  
Crystal Orientation ◽  
Turbine Blades ◽  
Lattice Parameter ◽  
Growth Direction ◽  
X Ray Diffraction ◽  
Single Crystalline ◽  
X Ray ◽  
Vertical Bridgman ◽  
Α Angle

The areas located near the cooling bores of single-crystalline cored turbine blades made of nickel-based CMSX-4 superalloy were studied. The blades were solidified by the vertical Bridgman technique in the industrial ALD furnace. Longitudinal sections of the blades were studied by Scanning Electron Microscopy, X-ray diffraction topography, X-ray diffraction measurements of the γ′-phase lattice parameter a, and the α angle of the primary crystal orientation. The local changes in α were analyzed in relation to the changes of the dendrite’s growth direction near the cooling bores. It was found that in the area approximately 3 ÷ 4 mm wide around the cooling bores, changes of α and a, both in the blade root and in the airfoil occurred. The local temperature distribution near the cooling bores formed a curved macroscopic solidification front, which caused changes in the chemical composition and, consequently, changes in the a value in a range of 0.002 Å to 0.014 Å. The mechanism of alloying elements segregation by tips of the dendrites on the bent solidification front was proposed. The multi-scale analysis that allows determining a relation between processes proceed both on a millimeter-scale and a micrometric and nanometric scale, was applied in the studies.

scholarly journals Thermal neutron detection using thin PEN film doped with high cross section materials

Energetika ◽  
2017 ◽  
Vol 63 (3) ◽  
Author(s):  
Jevgenij Garankin ◽  
Artūras Plukis ◽  
Elena Lagzdina
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Energy Deposition ◽  
Gamma Ray ◽  
Recoil Proton ◽  
Neutron Cross Section ◽  
Neutron Detection ◽  
Deep Blue ◽  
Neutron Reaction ◽  
Poly Ethylene

Poly(ethylene 2,6-naphthalate) (PEN) is promising as a new plastic scintillator, which emits deep-blue photons. Its photoluminescence emission peak (434–436 nm) and the decay time is of the order of 3 ns, as well as it is resistant to harsh environment. In this study, thin PEN film with high neutron cross section dopants was used for the thermal neutron detection. Iron boride, lithium tetraborate and lithium metaborate layers were coated on a 125 µm PEN film. Reaction particles from the boron neutron and lithium neutron reaction were detected by scintillation in PEN, and photomultiplier (PMT) pulses were registered and analysed. Energy deposition in the film samples was calculated using MCNP6 code taking into account losses in the source and air gap for the alpha particle source and incomplete energy deposition for the electrons. It was found that a small quantity of particles from the thermal neutron reaction could be detected in the strong neutron, gamma ray and recoil proton background.

scholarly journals Morphology and Photoluminescence of Ba0.5Sr0.5MoO4Powders by a Molten Salt Method

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ling Wei ◽  
Yunfei Liu ◽  
Yinong Lu ◽  
Tao Wu
Keyword(s):  
Molten Salt ◽  
Great Influence ◽  
Emission Peak ◽  
Molar Ratio ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
Soaking Time ◽  
X Ray ◽  
Structure Morphology ◽  
Phase Size

Ba0.5Sr0.5MoO4powders with scheelite-type tetragonal structure were successfully synthesized by a molten salt method. The structure, morphology, and luminescent property of the as-prepared powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL), respectively. The results show that the tetragonal Ba0.5Sr0.5MoO4powders were synthesized at 650°C for 6 h by the molten salt method. The calcining temperature, the soaking time, and the molar ratio of the salt to Na2MoO4have great influence on the phase, size, morphology, and PL properties. The better crystallinity and smaller particle size, the higher PL emission peak is.

Growth and characterization of single-crystal lead magnesium niobate–lead titanate via high-pressure vertical Bridgman method

2004 ◽  
Vol 19 (2) ◽  
pp. 609-615 ◽  
Author(s):  
Raji Soundararajan ◽  
Rabindra Nath Das ◽  
Russ Tjossem ◽  
Amit Bandyopadhyay ◽  
Kelvin G. Lynn ◽  
...  
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
Lead Titanate ◽  
Stoichiometric Composition ◽  
Growth Direction ◽  
Lead Magnesium Niobate ◽  
X Ray ◽  
Magnesium Niobate ◽  
Vertical Bridgman ◽  
Lead Magnesium

We have grown lead magnesium niobate–lead titanate (PMN–PT) single crystals, using the high-pressure vertical Bridgman (HPVB) technique, around the stoichiometric composition of 0.7 PMN–0.3PT [0.7Pb(Mg1/3Nb2/3)O3 + 0.3(PbTiO3)]. The final ingot (about 50-mm diameter, 25-mm long) was machinable using an inner diameter saw. The room-temperature x-ray diffraction on the starting powders and the final single crystal revealed a desirable perovskite structure. The natural growth direction in most of the crystals, as determined using orientation image microscopy, was (110). Examination of the final microstructures and phases/inclusions had been done using optical and infrared microscopy, energy dispersive spectroscopy, and x-ray backscatter techniques. Microstructural characterizations of the final ingots have revealed the presence of pores filled with Mg–Si–O-rich impurity phase, usually found along the cell boundary–like structures, in all the growths. We have measured some piezoelectric properties including d33 (1200 pC/N), k33 (0.85), kt (0.5), and the dielectric constant at the Curie temperature.

Synthesis of ZnO at Different Atomic Proportion Produced by Chemical Precipitation

2012 ◽  
Vol 1481 ◽  
pp. 127-133
Author(s):  
A. Medina ◽  
L. Béjar ◽  
G. Herrera-Pérez
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Composition ◽  
Chemical Precipitation ◽  
Growth Direction ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wurtzite Crystal Structure ◽  
Transmission Electron

ABSTRACTZinc oxide (ZnO) nanoparticles were produced using chemical precipitation synthesis with a molar ratio of 1:1, 1:2 and 1:3. The structure, chemical composition and morphology were investigated by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). XRD and EDS demonstrated that the all particles formed at different atomic proportion were of wurtzite crystal structure with the same chemical composition. SEM and TEM showed the formation of hexagonal particles with a molar ratio of 1:1 while the samples synthesized with a molar ratio 1:2 and 1:3 showed a circular shape. HRTEM and Fast Fourier Transform (FFT) demonstrated that the all particles were formed with a preferable [0001] growth direction.

Microstructure and Electrical Characterization of In-Doped Cd0.9Mn0.1Te Crystal Grown by the Vertical Bridgman Method

2013 ◽  
Vol 295-298 ◽  
pp. 322-325
Author(s):  
Zhen Wen Yuan ◽  
Lin Jun Wang ◽  
Ji Jun Zhang ◽  
Gao Li Wei ◽  
Kai Feng Qin ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Electrical Characterization ◽  
Compositional Analysis ◽  
Bridgman Method ◽  
X Ray ◽  
Vertical Bridgman Method ◽  
Ir Transmission ◽  
Te Inclusions ◽  
Vertical Bridgman

CdMnTe is one of the key materials for room temperature X-ray and gamma-ray detectors on Environmental Analysis and Monitoring. In this paper, the homogeneous Cd1-xMnxTe (x = 0.1) single crystal ingot was grown by the vertical Bridgman method. The compositional analysis was carried out by SEM/EDS. The Te inclusions were revealed by the IR transmission spectra. In dopant distribution was determined by ICP-AES measurement. The resistivity of CdMnTe was cha-racterized by I-V method. It was found that the segregation coefficient of Mn was 0.97. In dopant contents within 3 to 21 ppm of the ingot were found. The Te inclusions were mainly 8.2-28.3m in size and 1×105-1.5×107cm-3in concentration. I–V measurement reveals that sputtered Au film can form good ohmic contact and all the slices have the resistivity within 107 to 109Ωcm.

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