Thomson scattering of the core edge and divertor plasma regions of a tokamak with reactor technologies is discussed. The rationale and choice of technical solutions are given, the composition of the ...Thomson scattering diagnostic complex is discussed, as well as an estimate of the accuracy of measuring both electron temperature and density. Particular attention is paid to ensuring the functionality of the proposed diagnostics in the reactor mode of the tokamak operation and the results of testing diagnostic equipment in the experiments on Globus-M2 tokamak.
The results of an experimental investigation of the suppression of shock-induced flow separation and the elimination of transonic buffet in transonic flow regimes using tangential jet blowing onto ...the upper surface of a supercritical wing airfoil are presented. The experimental investigation is performed in the T-112 wind tunnel of the Central Aerohydrodynamic Institute (TsAGI). The results obtained for the baseline configuration and those with jet blowing are analyzed and compared. They showed that the tangential jet blowing suppresses the shock-induced flow separation, increases the lift, and delays the onset of the buffet.
The study investigated the sorption behaviour of
99
Tc and
125
I on bottom sediments from the Japan Sea, Khanka Lake and commercially available sapropel. It was determined that organic matter can ...have an impact on the iodine sorption process. After a 20-day period, sapropel reached an equilibrium state with a sorption value of up to 100%. In real systems of bottom sediment–water in the Far East region, iodine sorption was found to be superior on marine bottom sediments with a sorption value reaching 85% within 20 days, as opposed to freshwater sediments which only reached up to 35% within the same period. Tc(VII) in the form of pertechnetate anion exhibits no sorption under either aerobic or anaerobic conditions in the pH range of 4–11. Under aerobic conditions at pH 11 Tc(IV) is sorbed up to 15% only on sapropel; under anaerobic conditions at pH 7 the sorption reaches 25% for lake sediments, 10% for marine sediments and when the pH is 11, the sorption value of Tc by sapropel is as high as 100%.
The plasmaphysical code is presented that makes it possible to simulate the energy distributions of atoms escaping from plasma of the toroidal facilities. The code includes calculations of the ...particle spatial distributions in the charge-exchange plasma target consisting of atoms and hydrogen-like impurity ions. The calculations of the charge-exchange target are performed in two ways: using the Monte Carlo method and solving the ionization balance equation in the coronal approximation. The code can be used to interpret the neutral particle analyzers (NPAs) data. In particular, with its help, the ion temperatures determined using the NPAs can be corrected. The code can be also used to estimate the atomic fluxes from plasma onto the first wall expected at the currently designed fusion facilities.
A simple evolutionary algorithm is proposed to reconstruct a vector anomalous magnetic field from measurement data of one of its components. The algorithm selects the positions and magnetic moments ...of an assembly of point magnetic dipoles, the total magnetic field of which approximates with the required accuracy the data of single-component magnetic measurements at a known height above the earth’s surface. The distribution of sources obtained in this manner enables the reconstruction of all three components of the magnetic field. In this study, an evolutionary algorithm was utilized to solve the problem of reconstructing the magnetic field components
and
from the measured
vertical component data. Additionally, an iterative procedure was proposed for calculating the
,
and
components of the magnetic field from known data for the anomalous component of the geomagnetic field.
In this paper, results from the computational investigation of active species production in an argon microwave plasma torch are presented. We address the main paths of species creation and quenching ...and focus on their spatial distributions. We show that with the flowing Ar/O2 the radical production is relatively small. The operation of the argon torch can be more effective with an Ar/O2/N2 or Ar/O2/N2/H2O mixture as a feed gas. It was also shown that for high applied voltages the gas temperature inside the microwave torch can be high enough to significantly disturb the flow field. This disturbance can induce depletion and rarefaction of some species near the electrode and influence their production.
We have performed a numerical simulation of picosecond pulse propagation in a combined stretcher consisting of a segment of a telecommunication fibre and diffraction holographic gratings. The process ...of supercontinuum generation in a nonlinear photonic-crystal fibre pumped by picosecond pulses is simulated by solving numerically the generalised nonlinear Schrödinger equation; spectral and temporal pulse parameters are determined. Experimental data are in good agreement with simulation results. The obtained results are used to design a high-power femtosecond laser system with a pulse repetition rate of .
In modern large-sized tokamaks and those under construction, for example, in ITER, when measuring the average plasma electron density using the refractometry technique, it becomes necessary to study ...different effects that affect the measurement accuracy. This paper presents the results from studies of the high-temperature effects that can affect the interpretation of delay time measurements of the probing microwave signal in the ITER refractometry diagnostics. The criteria for applicability of different plasma models (“cold” plasma, modified “cold” plasma, and “hot plasma”) are obtained for calculating the plasma refractive index and interpreting the delay times that will be measured using the refractometry diagnostics of the ITER plasma. In the second article, based on the results obtained in this article, we will consider the influence of the high-temperature effects on the accuracy of determining the mean density using the refractometry diagnostics.
By using X-ray diffraction, transmission electron microscopy, ferromagnetic and electron paramagnetic resonances, Fe-filled multiwalled carbon nanotubes were studied. The iron within the nanotubes ...was found to be in three phases: the austenite
γ-Fe is located at the top of the nanotubes, while the ferrite
α-Fe and cementite
θ-Fe
3C are found close to the substrate. The morphology of the
α
+
θ mixture suggests that the eutectoid reaction
γ
→
α
+
θ occurs. Two ferromagnetic signals were observed and identified as those belonging to ferrite and cementite. Ferromagnetic signals revealed a surprising temperature dependence: with decreasing temperature, their integral intensity decreases nearly linearly, and the signals disappear at temperatures below 70
K. Possible reasons for this behaviour are discussed. Two paramagnetic signals appear at low temperatures. Based on their temperature behaviour and on the values of the
g-factors, the first signal is related to localized spin moments and the second one to free electrons.
In the paper, a new approach to identifying zones with rare anomalous manifestations of geological processes is proposed. The approach is based on two one-class classification methods of machine ...learning: the method of minimum area of alarm and the method of preference. The algorithm of minimum area of alarm is nonparametric. It is trained on a sample of anomalous events and computes the field of anomalous zones. The knowledge obtained by this method is non-verbalized. The method of preference allows approximating the obtained solution by a rather simple logical rule that defines the anomalous region in terms of analyzed properties of the geological environment. Examples of this approach to finding areas of possible foci of strong earthquakes and to make a regional forecast of deposits are considered.
