| 1. |
- Belotelov, V. I., et al.
(author)
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Magnetophotonic intensity effects in hybrid metal-dielectric structures
- 2014
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In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 89:4, s. 045118-
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Journal article (peer-reviewed)abstract
- The magneto-optical properties of a hybrid metal-dielectric structure consisting of a one-dimensional gold grating on top of a magnetic waveguide layer are studied experimentally and theoretically. It is demonstrated that a magnetic field applied in the longitudinal configuration (in the plane of the magnetic film and perpendicular to the slits in the gold grating) to the metal-dielectric structure modifies the field distribution of the optical modes and thus changes the mode excitation conditions. In the optical far field, this manifests in the alteration of the optical transmittance or reflectance when the structure becomes magnetized. This magneto-optical effect is shown to represent a novel class of effects related to the magnetic-field-induced modification of the Bloch modes of the periodic hybrid structure. That is why we define this effect as "longitudinal magnetophotonic intensity effect" (LMPIE). The LMPIE has two contributions, odd and even in magnetization. While the even LMPIE is maximal for the light polarized perpendicular to the grating slits (TM) and minimal for the orthogonal polarization (TE), the odd LMPIE takes maximum values at some intermediate polarization and vanishes for pure TM and TE polarizations. Two principal modes of the magnetic layer - TM and TE - acquire in the longitudinal magnetic field additional field components and thus turn into quasi-TM and quasi-TE modes, respectively. The largest LMPIE is observed for excitation of the antisymmetrical quasi-TE mode by TM-polarized light. The value of the LMPIE measured for the plasmonic structure with a magnetic film of Bi2Dy1Fe4Ga1O12 composition is about 1% for the even effect and 2% for the odd one. However, the plasmonic structure with a magnetic film with a higher concentration of bismuth (Bi2.97Er0.03Fe4Al0.5Ga0.5O12) gives significantly larger LMPIE: even LMPIE reaches 24% and odd LMPIE is 9%. Enhancement of the magneto-optical figure of merit (defined as the ratio of the specific Faraday angle of a magnetic film to its absorption coefficient) of the magnetic films potentially causes the even LMPIE to exceed 100% as is predicted by calculations. Thus, the nanostructured material described here may be considered as an ultrafast magnetophotonic light valve.
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| 2. |
- Belotelov, V. I., et al.
(author)
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Plasmon-mediated magneto-optical transparency
- 2013
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4, s. 2128-
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Journal article (peer-reviewed)abstract
- Magnetic field control of light is among the most intriguing methods for modulation of light intensity and polarization on sub-nanosecond timescales. The implementation in nanostructured hybrid materials provides a remarkable increase of magneto-optical effects. However, so far only the enhancement of already known effects has been demonstrated in such materials. Here we postulate a novel magneto-optical phenomenon that originates solely from suitably designed nanostructured metal-dielectric material, the so-called magneto-plasmonic crystal. In this material, an incident light excites coupled plasmonic oscillations and a waveguide mode. An in-plane magnetic field allows excitation of an orthogonally polarized waveguide mode that modifies optical spectrum of the magneto-plasmonic crystal and increases its transparency. The experimentally achieved light intensity modulation reaches 24%. As the effect can potentially exceed 100%, it may have great importance for applied nanophotonics. Further, the effect allows manipulating and exciting waveguide modes by a magnetic field and light of proper polarization.
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| 3. |
- Bergsåker, Henric, et al.
(author)
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First results from the Be-10 marker experiment in JET with ITER-like wall
- 2014
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In: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 54:8, s. 082004-
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Journal article (peer-reviewed)abstract
- When the ITER-like wall was installed in JET, one of the 218 Be inner wall guard limiter tiles had been enriched with Be-10 as a bulk isotopic marker. During the shutdown in 2012-2013, a set of tiles were sampled nondestructively to collect material for accelerator mass spectroscopy measurements of Be-10 concentration. The letter shows how the marker experiment was set up, presents first results and compares them to preliminary predictions of marker redistribution, made with the ASCOT numerical code. Finally an outline is shown of what experimental data are likely to become available later and the possibilities for comparison with modelling using the WallDYN, ERO and ASCOT codes are discussed.
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| 4. |
- Litnovsky, A., et al.
(author)
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Dust investigations in TEXTOR : Impact of dust on plasma-wall interactions and on plasma performance
- 2013
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In: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 438:Suppl., s. S126-S132
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Journal article (peer-reviewed)abstract
- Dust will have severe impact on ITER performance since the accumulation of tritium in dust represents a safety issue, a possible reaction of dust with air and steam imposes an explosion hazard and the penetration of dust in core plasmas may degrade plasma performance by increasing radiative losses. Investigations were performed in TEXTOR where known amounts of pre-characterized carbon, diamond and tungsten dust were mobilized into plasmas using special dust holders. Mobilization of dust changed a balance between plasma-surface interactions processes, significantly increasing net deposition. Immediately after launch dust was dominating both core and edge plasma parameters. Remarkably, in about 100 ms after the launch, the effect of dust on edge and core plasma parameters was vanished: no increase of carbon and tungsten concentrations in the core plasmas was detected suggesting a prompt transport of dust to the nearby plasma-facing components without further residence in the plasma.
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| 5. |
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| 6. |
- Razumovskii, I. M., 1985-, et al.
(author)
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Effect of the Particle Size of γ’ Phase on the Mechanical Properties of Ni base Superalloy
- 2011
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In: Euro Superalloys 2010. - : Trans Tech Publications Inc.. - 9783037851135 ; , s. 96-101
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Conference paper (peer-reviewed)abstract
- The effect of gamma’ particle size upon the mechanical properties of Ni base superalloy EP741NP obtained by powder metallurgy was investigated. The particle size of gamma’ phase in gamma-gamma’ microstructure was varied by changing the cooling rate V from the temperature of the solid solution treatment at 1200 C (V = 80, 200 and 400 C \ min.). After solid solution treatment billets were subjected to aging in the standard mode. It was established that as V increases from 80 to 200 C \ min., the average particle’s size of gamma’ phase decreases from 0.54 microns to 0.22 microns in the aged state. This improves the characteristics of creep and low cycle fatigue at 650C: time to rupture under load 1000 MPa increased from 132 hours to 416 hours and low cycle fatigue increased from 42,215 to 82,016 cycles.
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