A comparative investigation of the isotope effect in multi-scale anomalous transport phenomena is performed both experimentally by highly localized turbulence diagnostics in comparable hydrogen and ...deuterium FT-2 tokamak discharges and theoretically with the help of global gyrokinetic modeling. Substantial excess of the geodesic acoustic mode (GAM) amplitude, radial wavelength and correlation length in a wide spatial region of deuterium discharge resulting in stronger modulation of drift-wave turbulence level is demonstrated by both approaches. A larger turbulence radial correlation length is found at LFS in D-discharge in experiment and a stronger modulation of gyrokinetic particles and energy fluxes is shown there by the gyrokinetic code. The gyrokinetic modeling demonstrated comparable levels of drift wave density and electric field fluctuations in hydrogen and deuterium discharges. Nevertheless, the mean value of the ion energy and particle anomalous flux provided by modeling shows the systematic isotope effect at all radii.
The gyrokinetic full 5D particle distribution code ELMFIRE has been extended to simulate circular tokamak plasmas from the magnetic axis to the limiter scrape-off-layer. The predictive power of the ...code in the full-torus configuration is tested via its ability to reproduce experimental steady-state profiles in FT-2 ohmic L-mode plasmas. The results show that the experimental profile solution is not reproduced numerically due to the difficulty of obtaining global power balance. This is verified by cross-comparison of ELMFIRE code versions, which shows also the impact of boundary conditions and grid resolution on turbulent transport.
Isotope effect allows fusion devices to perform better when heavier hydrogen isotopes are used as fuel, but the reason for this improvement is not yet understood. We present the first direct evidence ...of the isotope effect on particle confinement in the FT-2 tokamak and investigate it via gyrokinetic simulations. Experimental measurements for comparable hydrogen and deuterium discharges show that the particle confinement time increases by 40% for the heavier isotope species. The isotope effect on particle flux is reproduced in global and local gyrokinetic simulations. Global ELMFIRE simulations demonstrate a systemic reduction in particle fluxes across the radial range, showing a ratio of fluxes Γ H Γ D = 1.3 at the edge and Γ H Γ D = 1.4 at r a = 0.6 . Local GENE simulations agree qualitatively with the result. Besides the fluctuation level, smaller scales and a favorable shift in the cross-phase between the turbulent fluctuations are found to contribute to the isotope effect in the simulations.
The thermoluminescent properties of PbCd
2
B
6
O
12
crystal phosphors
doped with Eu
3+
ions and exposed to β-ray irradiation are investigated. Polycrystalline samples of the initial matrix and solid ...solutions based on it were synthesized by solid-phase reactions and characterized by X-ray phase analysis, IR spectroscopy, and differential scanning calorimetry. The dependences of the thermoluminescence intensity on the concentration of the activator ions in the temperature range 25–400°C were obtained. The optimal composition of the phosphor Pb
1–
x
Cd
2
B
6
O
12
:
х
Eu
3+
(
x
= 0.05), which provides the maximum luminescence brightness, was determined.
Methods of reconstructing holographic images of objects made of the composite based on carbon fibermodified acrylonitrile-butadiene styrene and a thin electrically conductive film are presented. ...Holograms are obtained in the axial scheme when the collimating lens is placed on the source axis. Results of comparison of the calculated frequency response of the model transmission coefficient with measurements on an experimental setup are presented.
The paper studies autonomous monitoring systems for climate-soil parameters equipped with humidity sensors, atmospheric pressure sensors, air/soil temperature sensors, and carbon dioxide sensors. The ...hard- and software are proposed in this work. The operating principle of the monitoring system is described herein. Research results concern the dynamics of soil temperature changes in agricultural fields.
In this work, we have formed CuO memristive array embedded into porous SiO2 layer. Such an approach would create synaptic system on silicon substrate using standard integrated electronics operations. ...It also provides control over the geometric parameters of artificial synapses, which determines their synaptic weights. The results of synaptic behavior have shown that the value of synaptic weights and currents are dependent on the thickness of the CuO filled SiO2 porous layer.
The paper presents theoretical calculations and experimental data on the permittivity of conductive porous acrylonitrile butadiene styrene. It is found that spectrum regions with differential ...absorption are caused by the volume resonance of electromagnetic waves inside pores and in the matrix material between them. Resonant frequencies with increased differential absorption can be controlled by changing the pore space, dimension, and matrix permittivity.
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