the analysis of scientific publications and normative documents concerning properties, fields of using and methods of producing ultrapure water was made. Features of determination of electrical ...conductivity (resistivity) of ultrapure water as the method of the primary control of its quality were considered. The most effective and spread methods of producing ultrapure water on an industrial basis were described as well requirements to the process of its distribution, storage and use, whose fulfillment rules out degradation of water quality.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The behaviour of the fast particle population during 18 keV hydrogen and 26 keV deuterium neutral beam injection in deuterium plasmas is investigated. Experiments reveal large fast ion losses. The ...experimental results are confirmed using different types of modelling: simulation using the NUBEAM module, solution of the Boltzmann kinetic equation and solution of the 3D fast ion tracking algorithm. The dynamics of the energetic particle redistribution and losses during sawtooth oscillation and toroidal Alfvén eigenmodes are studied. A method to decrease fast ion losses under the current conditions (0.4 T, 0.2 MA) is shown. The influence of the plasma parameters on the energetic ion confinement rate is investigated. Modelling for the Globus-M2 conditions (1 T, 0.5 MA) is performed.
The influence of peripheral substitution and the nature of the macroheterocyclic heteroatoms on the basicity of hydrophilic 5,10,15,20-tetraarylporphyrins in the lowest excited singlet
S
1
state was ...studied using absorption and fluorescence spectroscopies. The basicity of the porphyrins themselves in the lowest excited singlet
S
1
state was found to decrease as compared to the ground
S
0
state. The difference in basicity constants p
K
a
depended on the nature of electronic communication between the macrocycle and peripheral substituents. In the case of an inductive effect of the substituents, the difference in the basicity constants p
K
a
was small, while mesomeric effects led to significant differences in the p
K
a
values. The cooperative nature of protonation, leading to almost simultaneous addition of two protons, was shown to be preserved in both cases. Replacement of a pyrrole with a thiophene in the macroheterocycle led to a decrease in cooperativity in both the ground
S
0
and the lowest excited singlet
S
1
states. The basicity constants characterizing the addition of the second and third protons by thia-substituted porphyrin differed significantly in the
S
1
state (p
K
a
2
– p
K
a
1
= 2), while they were close in the ground state. The activation entropy change ΔΔ
S
‡
upon protonation of the porphyrins in the lowest excited
S
1
state was compared to that in the ground
S
0
state.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The Globus-M spherical tokamak has demonstrated practically all of the project objectives during the 15-year period of operation. The main factor limiting further progress in plasma performance is a ...relatively low toroidal magnetic field. The maximum toroidal magnetic field achieved on Globus-M was 0.4 T with the exception of a limited number of shots with 0.55 T, which led to damage of the toroidal field coil in 2002. The increase of the magnetic field up to 1.0 T together with the plasma current up to 0.5 MA will result in the significant enhancement of the operating parameters in the upgraded Globus-M2 machine. The experimental program will be focused on plasma heating and non-inductive current drive and will contribute to the creation of a physical and technological base for the compact fusion neutron source development. In the article a brief overview of the physical background for the machine upgrade is outlined. The current status of the project implementation is described. First experimental results on moderate magnetic field increase from 0.4 T up to 0.5 T in the existing Globus-M machine are discussed. The improvement of plasma confinement as well as enhancement of efficiency of the beam driven current is observed.
Abstract
New data about the state of Cr
3+
doping ions in a single crystal of YGa
3
(BO
3
)
4
have been obtained by studying different methods. Using electron paramagnetic resonance, it was found ...that the Cr
3+
ions substitute the trivalent gallium ions. The obtained spin Hamiltonian parameters of the Cr
3+
ions in the YGa
3
(BO
3
)
4
single crystal (g = 1.9743 ± 0.0004; D = −0.465 ± 0.001 cm
−1
; E = −0.013 ± 0.001 cm
−1
) were analyzed and compared with those in TmAl
3
(BO
3
)
4
, EuAl
3
(BO
3
)
4
, and YAl
3
(BO
3
)
4
. The deviation of the Z-axis in the spectrum from the crystallographic axis С
3
is 1,7 degrees in YGa
3
(BO
3
)
4
.
In situ
X-ray diffraction was used to study the structural and elastic properties of huntite-type borates in the temperature range of RT-1073 K. In the radioluminescence (RL) spectra, the Cr
3+
-related emission bands were observed in the red wavelength range, and the presence of other defect-related bands was also registered in some cases. Thermally stimulated luminescence (TSL) glow curves were acquired over a wide temperature range, and the trap depths of the most prominent bands were calculated. The
11
B NMR spectra show that two nonequivalent spectral components exist for BO
3
structural elements.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Abstract
The NPA based diagnostic complex in ITER consists of four diagnostics: the neutral particle analyzers, the diamond neutral particle spectrometer, the gamma-ray spectrometer, and the neutron ...spectrometer. The diagnostics are located in equatorial port #11 and share the same vacuum channel. The present paper considers the physical basis of the diagnostic complex and its measurement capabilities in ITER. In addition, the design of the complex and the engineering solutions implemented to meet the ITER requirements are described.
Abstract
Active NPA measurements of the fast ion distribution using the neutral beam as an additional charge exchange target are discussed. Expressions for the calculation of the NPA signal based on ...the fast ion distribution and for the reconstruction of the fast ion distribution from the NPA signal are provided. Demonstration of the described approach is carried out on the Globus-M2 spherical tokamak, where a scanning system for the NPAs was recently installed. Main features of the active NPA application on Globus-M2 are considered. The energy and spatial distributions of fast deuterium ions at dedicated pitch angles are obtained and compared with the calculated ones. Key traits of the obtained distributions are considered and explained.
The spectral and luminescent properties of hydrophilic 21-thia-5,10,15,20-tetra(4-sulfonatophenyl)porphyrin and 5,10,15,20-tetra(4-sulfonatophenyl)porphyrin in solutions at 293 K were compared. ...Peculiarities of halochromic effects due to the replacement of a pyrrole by a thiophene ring in the macrocycle were revealed for the first time. Multicenter interactions on the periphery and in the core of the macrocycle led to modulation of spin–orbit couplings, which became apparent in changes of the fluorescence quenching efficiency. Fluorescence of the doubly protonated heteroporphyrins was shown to be quenched as compared to the free bases whereas fluorescence enhancement was observed for the doubly protonated forms.
The possibilities of using active neutral particle diagnostics for measuring local ion temperatures and isotopic ratio of deuterium-tritium plasma at the tokamak with reactor technologies are ...considered. Options for positioning the neutral particle analyzer relative to the diagnostic injector are presented. The fluxes of deuterium and tritium atoms escaping out of plasma were simulated in a wide range of plasma densities and temperatures. It is shown that the neutral particle analyzer active diagnostics will make it possible to measure the plasma parameters mentioned with the spatial and time resolutions of ~14 cm and ~0.01–0.1 s, respectively.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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