<Advanced Energy Generation Division> Advanced Atomic Energy Research Section

3-1. Research Activities in 202

Mixed-Ligand Complexes of Fe(II) & Cu(II) with Alizarin Maroon as a Primary Ligand & 5-Sulphosalicylic Acid as a Secondary Ligand

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Mott Transition and Spin Structures of Spin-1 Bosons in Two-Dimensional Optical Lattice at Unit Filling

We study the ground state properties of spin-1 bosons in a two-dimensional optical lattice, by applying a variational Monte Carlo method to the S=1 Bose-Hubbard model on a square lattice at unit filling. A doublon-holon binding factor introduced in the trial state provides a noticeable improvement in the variational energy over the conventional Gutzwiller wave function and allows us to deal effectively with the inter-site correlations of particle densities and spins. We systematically show how spin-dependent interactions modify the superfluid-Mott insulator transitions in the S=1 Bose-Hubbard model due to the interplay between the density and spin fluctuations of bosons. Furthermore, regarding the magnetic phases in the Mott region, the calculated spin structure factor elucidates the emergence of nematic and ferromagnetic spin orders for antiferromagnetic ($U_2>0$) and ferromagnetic ($U_2<0$) couplings, respectively.Comment: 5 pages, 5 figures, to appear in Journal of the Physical Society of Japa

Effects of Metal Hydride Coatings at the Electrodes on Neutron Production Rate in a Discharge-Type Fusion Neutron Source

A glow discharge (GD) fusion neutron source that utilizes nuclear fusion reactions of deuterium has been upgraded. The fusion reactions in this device mainly occur by collisions between the charged or neutral particles and the hydrogen isotopes trapped at the surface of electrodes. In addition, it is known that the metal hydride coating on the electrode enhances the neutron production rate (NPR). Therefore, the elemental distribution, including deuterium, in the depth direction on the electrode is an essential factor in neutron production. However, the distribution on the electrode has not been experimentally investigated. This study aims to analyze the distribution experimentally and indicate the effect of the metal hydride coatings. To achieve this purpose, we prepared the titanium (Ti)-coated cathode and the uncoated cathode, of which the base material was stainless steel. After that, the neutron production test was performed in the range of from 5-to 40-mA currents and from 20-to 60-kV applied voltage. This test indicated that the NPR was improved by coating the cathode with Ti than the uncoated cathode. In addition, depth profiling on the cathodes by glow discharge optical emission spectroscopy (GD-OES) was performed. While the analysis indicated that the concentration of deuterium on both cathodes was increased after the test, there was no significant difference in the concentration of deuterium between both cathodes. Furthermore, the concentration of Ti on the Ti-coated cathode was vastly decreased. The cause of these changes needs to be investigated

Quantum Simulation of Antiferromagnetic Spin Chains in an Optical Lattice

Understanding exotic forms of magnetism in quantum mechanical systems is a central goal of modern condensed matter physics, with implications from high temperature superconductors to spintronic devices. Simulating magnetic materials in the vicinity of a quantum phase transition is computationally intractable on classical computers due to the extreme complexity arising from quantum entanglement between the constituent magnetic spins. Here we employ a degenerate Bose gas confined in an optical lattice to simulate a chain of interacting quantum Ising spins as they undergo a phase transition. Strong spin interactions are achieved through a site-occupation to pseudo-spin mapping. As we vary an applied field, quantum fluctuations drive a phase transition from a paramagnetic phase into an antiferromagnetic phase. In the paramagnetic phase the interaction between the spins is overwhelmed by the applied field which aligns the spins. In the antiferromagnetic phase the interaction dominates and produces staggered magnetic ordering. Magnetic domain formation is observed through both in-situ site-resolved imaging and noise correlation measurements. By demonstrating a route to quantum magnetism in an optical lattice, this work should facilitate further investigations of magnetic models using ultracold atoms, improving our understanding of real magnetic materials.Comment: 12 pages, 9 figure

Space Mapping and Defect Correction

In this chapter we present the principles of the space-mapping iteration techniques for the efficient solution of optimization problems. We also show how space-mapping optimization can be understood in the framework of defect correction. We observe the difference between the solution of the optimization problem and the computed space-mapping solutions. We repair this discrepancy by exploiting the correspondence with defect correction iteration and we construct the manifold-mapping algorithm, which is as efficient as the space-mapping algorithm but converges to the true solution. In the last section we show a simple example from practice, comparing space-mapping and manifold mapping and illustrating the efficiency of the technique

Experimental investigation of planar ion traps

Chiaverini et al. [Quant. Inf. Comput. 5, 419 (2005)] recently suggested a linear Paul trap geometry for ion trap quantum computation that places all of the electrodes in a plane. Such planar ion traps are compatible with modern semiconductor fabrication techniques and can be scaled to make compact, many zone traps. In this paper we present an experimental realization of planar ion traps using electrodes on a printed circuit board to trap linear chains of tens of 0.44 micron diameter charged particles in a vacuum of 15 Pa (0.1 torr). With these traps we address concerns about the low trap depth of planar ion traps and develop control electrode layouts for moving ions between trap zones without facing some of the technical difficulties involved in an atomic ion trap experiment. Specifically, we use a trap with 36 zones (77 electrodes) arranged in a cross to demonstrate loading from a traditional four rod linear Paul trap, linear ion movement, splitting and joining of ion chains, and movement of ions through intersections. We further propose an additional DC biased electrode above the trap which increases the trap depth dramatically, and a novel planar ion trap geometry that generates a two dimensional lattice of point Paul traps.Comment: 11 pages, 20 figure

A crossed vortex bottle beam trap for single-atom qubits

We demonstrate trapping and quantum state control of single Cesium atoms in a 532 nm wavelength bottle beam trap. The three dimensional trap is formed by crossing two unit charge vortex beams. Single atoms are loaded with 50% probability directly from a magneto-optical trap. We achieve a trapping lifetime of up to 6 s, and demonstrate fast Rabi oscillations with a coherence time of $T_2\sim 43 \pm 9\rm ms$.Comment: 5 figures, minor edits to text and figures, to appear opt. let

Microstructure and Mechanical Properties of Ti-Mo-Zr-Cr Biomedical Alloys by Powder Metallurgy

[EN] Titanium and its alloys have been widely used as biometals due to their excellent biocompatibility, corrosion resistance and moderate mechanical properties. Ti-15Mo-6Zr-based alloys and a series of Ti-15Mo-6Zr-xCr (x = 1, 2, 3, 4 wt.%) alloys were designed and fabricated by powder metallurgy for the first time to develop novel biomedical materials. The microstructure, internal porosity and mechanical properties of the sintered Ti-15Mo-6Zr and Ti-15Mo-6Zr-xCr alloys were investigated using scanning electronic microscopy (SEM) and bending and compression tests. The experimental results indicated that the microstructure and mechanical properties of these alloys changed as different Cr levels were added. The addition of small Cr levels further increased the &#946;-phase stability, improving the properties of the Ti-15Mo-6Zr-xCr alloy. However, all of the alloys had good ductility, and the Ti-15Mo-6Zr-2Cr alloy had lower bending and compression moduli (31 and 23 GPa, respectively) than the Ti-15Mo-6Zr-based alloys (40 and 36 GPa, respectively). Moreover, the Ti-15Mo-6Zr-2Cr alloys exhibited higher bending and compression strength/modulus ratios, which were as large as 48.4 and 52.2, respectively; these were higher than those of the Ti-15Mo-6Zr-based alloy (41.3 and 33.6, respectively). In the search for a better implant material, &#946; phase Ti-15Mo-6Zr-2Cr, with its low modulus, ductile properties and reasonably high strength, is a promising candidate.The authors thank the Ministry of Economy and Competitiveness for financially supporting the research project MAT2014-53764-C3-1-R and the European Commission through the Erasmus Mundus scholarship program WELCOME. The European Commission via FEDER funds allowed for the purchase of equipment for research and Microscopy Service of the Polytechnic University of Valencia.Elshalakany, AB.; Ali, S.; Amigó Mata, A.; Eessaa, AK.; Mohan, P.; Osman, T.; Amigó, V. (2017). Microstructure and Mechanical Properties of Ti-Mo-Zr-Cr Biomedical Alloys by Powder Metallurgy. Journal of Materials Engineering and Performance. 26(3):1262-1271. doi:10.1007/s11665-017-2531-zS12621271263M. Geetha, A.K. Singh, R. Asokamani, and A.K. Gogia, Ti Based Biomaterials, the Ultimate Choice for Orthopaedic Implants—A Review, Prog. Mater Sci., 2009, 54, p 397–425M. Ahmed, D.G. Savvakin, O.M. Ivasishin, and E.V. Pereloma, The Effect of Ageing on Microstructure and Mechanical Properties of Powder Ti-5Al-5Mo-5V-1Cr-1Fe Alloy, Mater. Sci. Eng., 2014, A605, p 89–97M. Niinomi, Mechanical Biocompatibilities of Titanium Alloys for Biomedical Applications, J. Mech. Behav. Biomed. Mater., 2008, 1(30–4), p 2M.P. Licausi, A. IgualMun, and V.A. Borrás, Influence of the Fabrication Process and Fluoride Content on the Tribocorrosion Behaviour of Ti6Al4V Biomedical Alloy in Artificial Saliva, J. Mech. Behav. Biomed. Mater., 2013, 20(2013), p 137–148I. Cvijovic-Alagic, N. Gubeljak, M. Rakin, Z. Cvijovic, and K. Geric, Microstructural Morphology Effects on Fracture Resistance and Crack Tip Strain Distribution in Ti-6Al-4V Alloy for Orthopedic Implants, Mater. Des., 2014, 53, p 870–880Y.C. Chen, J.H. Chern Lin, and C.P. Ju, Effects of Post-aging Cooling Condition on Structure and Tensile Properties of Aged Ti-7.5Mo Alloy, Mater. Des., 2014, 54, p 515–519E.P. Lautenschlager and P. Monaghan, Titanium and Titanium Alloys as Dental Materials, Int. Dent. J., 1993, 43, p 245–253M. Long and H.J. Rack, Titanium Alloys in Total Joint Replacement—A Materials Science Perspective, Biomaterials, 1998, 19, p 1621–1639M. Long and H.J. Rack, Titanium Alloys in Total Joint Replacement a Materials Science Perspective, Biomaterials, 1998, 19, p 1621–1639M. Niinomi, Mechanical Properties of Biomedical Titanium Alloys, Mater. Sci. Eng., A, 1998, 243, p 231–236E. Cheal, M. Spector, and W. Hayes, Role of Loads and Prosthesis Material Properties on the Mechanics of the Proximal Femur After Total Hip Arthroplasty, J. Orthop. Res., 1992, 10, p 405–422J. Fan, M. Lu, H. Cheng, J. Tian, and B. Huang, Effect of Alloying Elements Ti, Zr on the Property and Microstructure of Molybdenum, Int. J. Refract. Met. Hard Mater., 2009, 27, p 78–82W.F. Ho, S.C. Wu, S.K. Hsu, Y.C. Li, and H.C. Hsu, Effects of Molybdenum Content on the Structure and Mechanical Properties of as-Cast Ti-10Zr-Based Alloys for Biomedical Applications, Mater. Sci. Eng., C, 2012, 32, p 517–522W.F.A. Ho, Comparison of Tensile Properties and Corrosion Behavior of Cast Ti-7.5Mo with c.p. Ti, Ti-15Mo and Ti-6Al-4V Alloys, J. Alloys Compd., 2008, 464, p 580–583Y.L. Zhou and D.M. Luo, Corrosion Behavior of Ti-Mo Alloys Cold Rolled and Heat Treated, J. Alloys Compd., 2011, 509, p 6267–6272N.T.C. Oliveira and A.C. Guastaldi, Electrochemical Stability and Corrosion Resistance of Ti-Mo Alloys for Biomedical Applications, Acta Biomater., 2009, 5, p 339–405Y. Chen, L. Xu, Z. Liu, F. Kong, and Z. Chen, Microstructures and Properties of Titanium Alloys Ti-Mo for Dental Use, Trans. Nonferrous Met. Soc. China, 2006, 16, p 824–828W.-F. Ho, S.-C. Wu, H.-W. Wanga, and H.-C. Hsu, Effects of Cr Addition on Grindability of Cast Ti-10Zr Based Alloys, Mater. Chem. Phys., 2010, 121, p 465–471M.J. Donachie, Titanium: A Technical Guide, 2nd ed., ASM International, Metals Park, 2000R.G. Craig, Restorative Dental Materials, 9th ed., CV Mosby, St. Louis, 1993H.C. Hsu, S.C. Wu, S.K. Hsu, T.F. Lin, and W.F. Ho, Structure and Mechanical Properties Of as-Cast Ti-5Nb-xCr Alloys, Mater. Des., 2013, 51, p 268–273H.-C. Hsu, S.-C. Wu, S.-K. Hsu, C.-T. Li, and W.-F. Ho, Effects of Chromium Addition on Structure and Mechanical Properties of Ti-5Mo Alloy, Mater. Des., 2015, 65, p 700–706J. Syarif, T.N. Rohmannudin, M.Z. Omar, Z. Sajuri, and S. Harjanto, Stability of the Beta Phase in Ti-Mo-Cr Alloy Fabricated by Powder Metallurgy, J. Min. Metall. Sect. B Metall., 2013, 49(3), p 285–292J. Syarif, E. Kurniawan, M.R. Rasani, Z. Sajuri, M.Z. Omar, and S. Harjanto, Influence of Oxygen on Microstructures of Ti-Mo-Cr Alloy, Adv. Mater. Res., 2014, 896, p 613–616E. Delvat, D.M. Gordin, T. Gloriant, J.L. Duval, and M.D. Nagel, Microstructure, Mechanical Properties and Cytocompatibility of Stable Beta Ti-Mo-Ta Sintered Alloys, J. Mech. Behav. Biomed. Mater., 2008, 1, p 345–351P. Wang, Y. Feng, F. Liu, and L.S. Guan, Microstructure and Mechanical Properties of Ti-Zr-Cr Biomedical Alloys, Mater. Sci. Eng., C, 2015, 51, p 148–152W.-F. Ho, S.-C. Wu, H.-H. Chang, and H.-C. Hsu, Structure and Mechanical Properties of Ti-5Cr Based Alloy with Mo Addition, Mater. 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Effect of bubble-bubble interaction in Cu−Al2O3/H2O hybrid nanofluids during multibubble growth process

This paper scrutinizes the nonlinear multibubble model with considering bubble-bubble (BB) interaction in Cu−Al2O3/water hybrid nanofluid over the vapour bubble radius in Newtonian mediums. Firstly, we present the derivation of the extended Rayleigh-Plesset (ERP) equation of multibubble under the effect of BB interaction in hybrid nanofluids based on the Navier-Stokes equation. The model is formulated by the continuity equation, the ERP in the hybrid nanofluids and the relations of thermophysical features in mono and hybrid nanofluids. The ERP equation is transformed into an ordinary differential equation using the non-dimensions variables methodology, which is then solved analytically using the modified Plesset-Zwick method. In addition, the current model presents the influence of BB interactions on growth process of multibubble in Cu−Al2O3/H2O hybrid nanofluids. As a result, the impact of increasing of the number of bubbles “n” and BB interactions in a hybrid nanofluid, at n=1,2,3 on the growth process are investigated. Moreover, it is found that the growth process of multibubble dynamics in hybrid nanofluid increases when the distance between BB interaction and volume concentration decrease. The growth of multibubble dynamics in Cu−Al2O3/water hybrid nanofluid is less than in the cases of water-base fluid and Al2O3/water nanofluids. Additionally, vapour bubble radii in the current study give a good agreement and lower behavior if compared with the prior investigations. © 202