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The plasma-wall transition is investigated by a one-dimensional steady-state multifluid model, which was presented in detail in Part I [T. Gyergyek et al., AIP Adv. 14, 045201 (2024)]. In this work, the plasma-wall transition is analyzed for the case where the plasma consists of singly charged positive ions, electrons, and singly charged negative ions. When the temperature and initial density of the negative ions are varied, a transition between two types of solutions of the model is observed. We call them the low and high solution, with respect to the absolute value of the potential drop. When the density and temperature of the negative ions are above a critical value, the low solution is observed. As the mass of the positive ions increases, these critical values also increase, but only until the ion mass is below about 1000 electron masses. With larger ion masses, the critical density of the negative ions and the temperature no longer change. In the low solution, the potential drop in front of the sheath is determined by the negative ions and is smaller in absolute terms than in the case of the high solution, where the potential drop in front of the sheath is determined by the electrons. If the problem is analyzed on the pre-sheath scale, the transition between the low and high solution is very sharp. However, when the neutrality condition is replaced by the Poisson equation, this transition becomes blurred and the solutions of the model equations exhibit oscillations. The role of the smallness parameter is highlighted. It is shown how the initial electric field is determined. Deviation of the negative ion density profile from the Boltzmann relation is discussed. [ABSTRACT FROM AUTHOR]

High-entropy alloys (HEA) are promising structural materials that will successfully resist high-temperature irradiation with helium ions and radiation-induced swelling in new generations of nuclear reactors. In this paper, changes in the elemental and phase composition, surface morphology, and structure of CoCrFeNi and CoCrFeMnNi HEAs irradiated with He2+ ions at a temperature of 700 °C were studied. Structural studies were mainly conducted using the X-ray diffraction method. The formation of a porous surface structure with many microchannels (open blisters) was observed. The average diameter of the blisters in CoCrFeMnNi is around 1.3 times smaller than in CoCrFeNi. It was shown that HEAs' elemental and phase compositions are stable under high-temperature irradiation. It was revealed that, in the region of the peak of implanted helium, high-temperature irradiation leads to the growth of tensile macrostresses in CoCrFeNi by 3.6 times and the formation of compressive macrostresses (−143 MPa) in CoCrFeMnNi; microstresses in the HEAs increase by 2.4 times; and the dislocation density value increases by 4.3 and 7.5 times for CoCrFeNi and CoCrFeMnNi, respectively. The formation of compressive macrostresses and a higher value of dislocation density indicate that the CoCrFeMnNi HEA tends to have greater radiation resistance compared to CoCrFeNi. [ABSTRACT FROM AUTHOR]

We study the optical response of solid gold driven by ultrashort pulses of visible light by tracking the conduction band density and damping rates. While we find rapid changes in optical properties during and shortly after the laser excitation, we obtain an almost unchanged reflectivity during the stage of electron–phonon temperature equilibration. These predictions are in good agreement with experimental data and exhibit a strong compensation of damping mechanisms as a source for the stable response, although electron and ion temperatures change significantly. Considering the complex interplay of damping processes in solid gold, our model gives a more fundamental interpretation of optical measurements than existing approaches. [ABSTRACT FROM AUTHOR]

In the given work, compliance with the distribution law of defect vacancies formed in ZrO2 crystal irradiated with 2 MeV energy H + ions at room temperature was studied (The fluxes density for the H + ion was chosen to be 1017 ions/cm2). The effect of H + ions with fluxes density at different temperatures (500∘C, 600∘C, 700∘C, 800∘C and 900∘C) on W and S parameters was determined. The mechanism of formation of nanoclusters in the ZrO2 crystal structure under the influence of H + radiation, the vacancy cluster formed by 2Zr vacancies and 4O vacancies, and its location in triple spaces with hydrogen atoms were determined. 2Zr and 4 vacancies were determined by the τ values of the vacancy clusters growing under the influence of radiation and the positions of hydrogen atoms in the 1VZr, 1VO, di-VZrO triple-VZrO2 vacancy groups. [ABSTRACT FROM AUTHOR]

SPARC will be outfitted with three systems of x-ray crystal spectrometer arrays. Two of these are designed using cylindrically bent crystals to achieve high spectral-resolution for ion temperature and toroidal velocity measurements via imaging He-like Kr and Ne-like Xe. The last acts as a spectral survey system to monitor Ne-like W and nearby H- and He-like emission from Cr, Fe, Co, Ni, and Cu. Line radiation intensities are calculated using the Flexible Atomic Code for atomic data and ColRadPy for collisional-radiative modeling, then convoluted with a Voigt line shape. Free–free, free-bound, and two-photon continuum radiation is also included. The ToFu code is used to perform volume-of-sight integration to produce synthetic detector images. In addition, presented is cross-validation performed using the XICSRT Monte Carlo ray-tracing code. Ion temperature and toroidal velocity profiles are reconstructed using ToFu via tomographic inversion. [ABSTRACT FROM AUTHOR]

The next-generation magnetic recoil spectrometer (MRSnext) is being designed to replace the current MRS at the National Ignition Facility and OMEGA for measurements of the neutron spectrum from an inertial confinement fusion implosion. The MRSnext will provide a far-superior performance and faster data turnaround than the current MRS systems, i.e., a 2× and 6× improvement in energy resolution at the NIF and OMEGA, respectively, and 20× improvement in data turnaround time. The substantially improved performance of the MRSnext is enabled by using electromagnets that provide a short focal plane (12–16 cm) and unprecedented flexibility for a wide range of applications. In addition to being able to measure neutron yield, apparent ion temperature, areal density, and plasma-flow velocity over a wide range of yields, the NIF MRSnext will be able to directly, uniquely assess the alpha heating of the fuel ions through measurements of the alpha knock-on tail in the neutron spectrum. The goal is to implement a radiation-hard electronic detection system capable of providing rapid data acquisition and analysis. The development of the MRSnext will also set the foundation for the more advanced, time-resolving MRSt and serve as a testbed for its implementation on the NIF. [ABSTRACT FROM AUTHOR]

This paper presents an overview of recent hardware extensions and data analysis developments to the Wendelstein 7-X visible core spectroscopy systems. These include upgrades to prepare the in-vessel components for long-pulse operation, nine additional spectrometers, a new line of sight array for passive spectroscopy, and a coherence imaging charge exchange spectroscopy diagnostic. Progress in data analysis includes ion temperatures and densities from multiple impurity species, a statistical comparison with x-ray crystal spectrometer measurements, neutral density measurements from thermal passive Balmer-alpha emission, and a Bayesian analysis of active hydrogen emission, which is able to infer electron density and main ion temperature profiles. [ABSTRACT FROM AUTHOR]

Coherence Imaging Charge Exchange Recombination Spectroscopy (CICERS) is an imaging diagnostic installed in Wendelstein 7-X from which 2D maps of ion temperature (Ti) and impurity density (nZ) are obtained. The improved spatial resolution and coverage, as compared to standard Charge eXchange Recombination Spectroscopy (CXRS), with which these parameters can be assessed, come at the expense of spectral resolution, requiring the development of new strategies to isolate the active charge exchange contribution from passive and Bremsstrahlung radiation. In this work, a new approach based on the modeling of background radiation is presented and applied to the derivation of 2D Ti maps. These are compared to the Ti profiles derived from standard CXRS, which found excellent agreement up to the edge (ρ > 0.8). The CICERS view is implemented in the pyFIDAsim code, which is used to provide further insight into the spatial localization of the radiation as measured by the diagnostic. Moreover, an absolute intensity calibration is carried out, and, coupled with pyFIDAsim, the first 2D nC maps are obtained and validated against CXRS data. [ABSTRACT FROM AUTHOR]

A high-fidelity synthetic diagnostic has been developed for the ITER core x-ray crystal spectrometer diagnostic based on x-ray ray tracing. This synthetic diagnostic has been used to model expected performance of the diagnostic, to aid in diagnostic design, and to develop engineering tolerances. The synthetic model is based on x-ray ray tracing using the recently developed xicsrt ray tracing code and includes a fully three-dimensional representation of the diagnostic based on the computer aided design. The modeled components are: plasma geometry and emission profiles, highly oriented pyrolytic graphite pre-reflectors, spherically bent crystals, and pixelated x-ray detectors. Plasma emission profiles have been calculated for Xe44+, Xe47+, and Xe51+, based on an ITER operational scenario available through the Integrated Modelling & Analysis Suite database, and modeled within the ray tracing code as a volumetric x-ray source; the shape of the plasma source is determined by equilibrium geometry and an appropriate wavelength distribution to match the expected ion temperature profile. All individual components of the x-ray optical system have been modeled with high-fidelity producing a synthetic detector image that is expected to closely match what will be seen in the final as-built system. Particular care is taken to maintain preservation of photon statistics throughout the ray tracing allowing for quantitative estimates of diagnostic performance. [ABSTRACT FROM AUTHOR]

The linear and nonlinear effects of hydrogen isotope species on ion temperature gradient (ITG) instability in the Large Helical Device (LHD) stellarator are studied using radially global gyrokinetic simulation. We found that the coupling range of linear toroidal harmonics depends on the ion mass of the hydrogen isotope. The growth rates of ITG mode are almost the same for H, D, and T plasmas, indicating a gyro-Bohm scaling of ion-mass dependence. The nonlinear electrostatic simulations show that the zonal flow breaks the radially elongated eigenmode structures and reduces the size of the turbulence eddies, which suppresses the turbulence and the ion heat transport in the LHD. The turbulence amplitude without the zonal flow is almost the same for H, D, and T plasmas, while it decreases with increasing ion mass of the hydrogen isotope when the zonal flow is present. The reduction of the turbulent transport with larger ion mass is mostly due to the enhancement of zonal flows by larger ion mass. The ion heat conductivity deviates from the gyro-Bohm scaling for both cases with and without the zonal flow. [ABSTRACT FROM AUTHOR]

We synthesized Eu3+-doped CsY 2 F 7 and RbY 2 F 7 nanoparticles (orthorhombic crystal structure, Pnna space group, No. 52) by the microwave-assisted solvothermal technique and investigated the influence of reaction temperature and fluoride ion concentration on the particles' phase and crystal structure. Fluoride ions were added in excess of the stoichiometric amount to achieve the orthorhombic phase for C s Y 2 F 7 and to convert the cubic RbY 3 F 10 to the orthorhombic RbY 2 F 7. Mild synthesis conditions yielded nanoparticles with crystallites ranging in size from 19 to 37 nm and a combination of spherical, rod-like, and hexagonal shapes. Nanoparticles emit a strong orange and red light when excited into the Eu3+5L 6 level, which is centered around 390 nm. The strongest emission peak is around 612 nm, which comes from the 5D 0 →7F 2 electronic transitions. Emission intensity dependence on Eu3+ concentration revealed that nanoparticles can be heavily doped with Eu3+, up to 25 % with respect to Y3+. Emission decay measurements provided values of excited state lifetimes of 6.2 ms for the Cs(Y 0.75 Eu 0.25) 2 F 7 and 6.0 ms for the Rb(Y 0.75 Eu 0.25) 2 F 7. [ABSTRACT FROM AUTHOR]

The azimuthal dynamics of ions along the inner pole of a Hall thruster with a centrally mounted cathode and a magnetic shielding topography are experimentally investigated. A time-averaged laser-induced fluorescence diagnostic is implemented to characterize the azimuthal ion velocity distribution, and its moments are computed numerically to infer bulk rotation speed and ion temperature. It is found that the time-averaged ion swirl velocity grows to 2 km/s in the near-pole region, and the cathode ions exhibit ion temperatures in the azimuthal direction approaching 8 eV. Both of these quantities exceed the speeds and temperatures anticipated from classical acceleration and heating. Time-resolved laser-induced fluorescence is then employed to investigate the role of plasma fluctuations in driving the time-averaged ion properties. Semicoherent fluctuations at 90 kHz are observed in the ion velocity distribution and its associated moments. These oscillations are correlated with the gradient-driven anti-drift wave, which propagates azimuthally in the near-field cathode plume. Quasilinear theory is used to construct a 1D model for acceleration and heating of the ion population as a result of the anti-drift mode. This approach demonstrates qualitative agreement with the time-averaged ion velocity and temperature, suggesting that the anti-drift mode may be a dominant driver of azimuthal ion acceleration and heating in front of the cathode keeper and the inner half of the inner front pole cover. These results are discussed in terms of their relevance to the erosion of thruster surfaces in the near-field cathode plume. [ABSTRACT FROM AUTHOR]

This work reports that Biermann self-generated magnetic fields of ≈ 200 MG and Hall parameters of ≈ 1.5 are produced in the stagnation phase of direct-drive cryogenic implosions at Omega. The magnetic fields produce a drop of 2.4% in fusion yield and 1% in ion temperature. A quantitative estimate of the effect of self-generated magnetic fields on yield and ion temperature is essential, since direct measurements of these fields are not available. Reconstructed simulations of the 50 Gbar implosions, with all the stagnation measurements reproduced simultaneously by a combination of mid- and low-mode asymmetries as degradation mechanisms [Bose et al., Phys. Plasmas 25, 062701 (2018)], are used to obtain the estimates. The magnetic fields cause a decrease in yield due to the Righi–Leduc heat flow, which exceeds any benefits from heat flow suppression due to magnetization. It is important to note that both direct-drive Omega-scale implosions and indirect-drive National Ignition Facility (NIF)-scale implosions [Walsh et al., Phys. Rev. Lett. 118, 155001 (2017)] produce similar estimates for the magnetic field strength, and both show a decrease in fusion yield, with the Righi–Leduc transport as the loss mechanism. However, the yield degradation at Omega is small and lower by ≈ 5 × compared to the indirect-drive ignition-scale NIF estimate. [ABSTRACT FROM AUTHOR]

The nature and type of defects formed due to heavy-ion irradiation in tungsten foils are analyzed using transmission electron microscopy. The recrystallized tungsten foils were irradiated by 80 MeV gold ions at room temperature for a fluence of 1.3 × 10 14 ions/cm 2 that amounts to a net displacement per atom (dpa) of 0.22. The defect structures were analyzed using bright-field and weak-beam dark field imaging at two different depths to understand the depth profile of the defects. It is found that the defect clusters formed during the irradiation, both at the near-surface and at 2 μ m depth are of vacancy type that is confirmed by the local strain analysis and supports the findings of vacancy clusters in positron lifetime measurements. The analysis also shows that the dislocation-lines were of pure edge, pure screw and mixed. The fraction of mixed dislocation is found to increase during irradiation at the expense of pure edge and screw dislocations. [ABSTRACT FROM AUTHOR]

The study of ion-acoustic solitons (IASs) in an unmagnetised collisionless plasma system having inertial fluid ions and two temperature hot as well as cold electrons obeying Cairns–Tsallis (CT) distribution is presented. Using reductive perturbation method, the KdV equation is derived. Further, introducing higher-order effects of nonlinearity and dispersion, a nonlinear KdV-type inhomogeneous equation is derived that supports the formation of dressed solitons. The combined effects of higher-order corrections and various plasma parameters are analysed on the characteristics of the different kinds of ion-acoustic solitons with implications to Saturn's magnetosphere. [ABSTRACT FROM AUTHOR]

Herein, the structural properties and chemical composition of Ge samples implanted with tellurium at cryogenic temperatures are analyzed, focusing on the role of the native oxide. For germanium, cryogenic‐temperature implantation is a requirement to achieve hyperdoped impurity concentrations while simultaneously preventing surface porosity. In this work, the critical role of the thin native germanium oxide is demonstrated when performing ion implantations at temperatures close to the liquid nitrogen temperature. The structural and chemical composition of tellurium‐implanted samples as a function of the implanted dose from 5 × 1014 to 5 × 1015 cm−2 is analyzed. After a laser melting process, the incorporated oxygen is diffused to the surface forming again a GeOx layer which retains a large fraction of the total implanted dose. These detrimental effects can be eliminated by a selective etching of the native oxide layer prior to the ion implantation process. These effects have been also observed when implanting on Si substrates. This work identifies key aspects for conducting implantations at cryogenic temperatures, that are otherwise negligible for ion implanting at room temperature. [ABSTRACT FROM AUTHOR]

The ion-acoustic instability in the tails of meteoroids as a result of their passage through the Earth's atmosphere is studied and the conditions under which it develops are given. The development of this instability occurs as a result of the relative motion of the plasma of meteoroid tails and the dusty plasma of the Earth's ionosphere. Dust, in turn, creates conditions when this instability can develop in a situation of approximately equal ion and electron temperatures, which is observed in the plasma–dust system under consideration. The mechanism of the excitation of ion-sound waves as a result of the development of the ion-acoustic instability in meteoroid tails is shown. The growth rates of the ion-acoustic instability and the characteristic times of its development are found. It is shown that the instability has time to develop during the time of passage of a meteoroid body in the Earth's atmosphere and the formation of a meteoroid trail, which has values much greater than the time of development of ion-acoustic instability in the system under consideration. The wave vectors and velocities of meteoric bodies, at which the development of the ion-acoustic instability is expected, are found. It is noted that the instability can reach a nonlinear regime at possible large wave amplitudes. [ABSTRACT FROM AUTHOR]

This paper focuses on the theoretical study of the burning rate of D-T fuel in Z-pinch devices with magneto-inertial confinement. The investigated nuclear fusion process involved fast laser ignition of a mixed D-T fuel contained in a capsule at a temperature of 10 keV, influenced by a strong electromagnetic field. The D-T, D-D, D-3He, 3He-3He, and T-T fusion reactions were employed in the calculations. Based on modern experimental fit data of nuclear fusion reaction rates, the particle and energy balance equations, along with their numerical solutions, were considered, utilizing the ion densities of charged particles such as protons, deuterium, tritium, 3He, and 4He ions. The plasma was in a hot, ultra-dense state, under the quasi-neutrality condition, with initial deuterium and tritium densities of 5 × 10 23 cm−3 and an electron density of 10 × 10 23 cm−3. The ion and electron temperatures were considered equal in this paper. The time dependencies of the ion densities, plasma temperature, energy yield from charged ions and neutrons, fusion power density, and bremsstrahlung radiation loss were investigated. [ABSTRACT FROM AUTHOR]

In this article, carbon dots (CDs) are fabricated via hydrothermal carbonization (HTC) at different temperatures ranging from 120 to 210 °C. Regarding the temperature variations, they demonstrate a crucial role in specific identification in the ability to differentiate the chemical structures and optical properties of the resulting CD features. Both heteroatoms‐doped core structure, and the functionalized surface state display a changed that correlates with the temperature variations mentioned. The CDs which are synthesized at 180 °C contain the appropriate balance of doped heteroatoms and surface functional groups which further display the most promising performance of the quenching effect of up to 17% toward ferric ions. This work contributes to the growing understanding of CDs and provides valuable insights for the future development of applications that may favor certain interest in the creation or designing process in various applications. [ABSTRACT FROM AUTHOR]

Rotation/spin of plasma blob in the edge and SOL regions in the presence of interchange plasma turbulence with a finite ion temperature gradient ( $ \nabla _\perp T_i $ ∇ ⊥ T i ) has been presented. $ \nabla _\perp T_i $ ∇ ⊥ T i destabilizes plasma, but damps the eddies related to the plasma blob by enhanced viscosity, therefore, rotation is important for plasma dynamics as the rotation further stabilizes the blobs. The turbulence has been simulated numerically and results show monopolar vorticity is responsible for blob rotation, but the physics is different in the edge and SOL regions. A radial profile of vorticity, and angular speed of a typical plasma blob have been presented. The role of $ \nabla _\perp T_i $ ∇ ⊥ T i has been identified. [ABSTRACT FROM AUTHOR]

Low-frequency drift-wave instabilities play a crucial role in the radial transport of present-day tokamaks, and trapped electron collisions can significantly influence these instabilities. In this paper, the effects of trapped electron collisions on these instabilities are investigated based on linear gyro-kinetic simulations. The basic numerical techniques including dispersion relation integral method and orthogonal basis function expansion are presented in detail with necessary benchmark work. The results demonstrate that in medium gradients, the increase of trapped electron proportions promotes the growth rate and radial heat transport largely for quasi-linear trapped electron modes (TEMs) and ion temperature gradient (ITG) modes. Moreover, trapped electron collisions have strong stabilizing effects, especially for TEMs driven by electron temperature gradients. Two distinctive branches, namely Mode #1 and #2, are investigated in steep gradients. Both behave in a varied instability nature during different ranges of the normalized wave vector k ^ θ . Mode #1 mainly induces radial heat transport during k ^ θ < 0.5 and is significantly suppressed by the collisions. Mode #2 mainly induces radial heat transport during 0.4 < k ^ θ < 0.8 , and is largely enhanced by the collisions. When the collisionality is large enough, Mode #2 has stronger transport capacity than the other. Mode #2 at the medium wave vector, known as dissipative TEM, may provide the mechanism of the edge coherent mode observed in EAST H-mode plasmas, wherein collisionality plays an important role in the mode excitation. [ABSTRACT FROM AUTHOR]

A reduced kinetic method (RKM) with a first-principles collision operator is introduced in a 1D2V planar geometry and implemented in a computationally inexpensive code to investigate non-local ion heat transport in multi-species plasmas. The RKM successfully reproduces local results for multi-species ion systems and the important features expected to arise due to non-local effects on the heat flux are captured. In addition to this, novel features associated with multi-species, as opposed to single species, cases are found. Effects of non-locality on the heat flux are investigated in mass and charge symmetric and asymmetric ion mixtures with temperature, pressure, and concentration gradients. In particular, the enthalpy flux associated with diffusion is found to be insensitive to sharp pressure and concentration gradients, increasing its significance in comparison to the conductive heat flux driven by temperature gradients in non-local scenarios. The RKM code can be used for investigating other kinetic and non-local effects in a broader plasma physics context. Due to its relatively low computational cost it can also serve as a practical non-local ion heat flux closure in hydrodynamic simulations or as a training tool for machine learning surrogates. [ABSTRACT FROM AUTHOR]

The dynamical behavior of the capacitively coupled Ar plasma driven by four frequencies (54, 80, 94 and 100 MHz) at fixed pressure are simulated by the particle-in-cell/Monte-Carlo collisions (PIC/MCC) model based on the electromagnetic field. The magnetic field is generated by plasma current itself. The results show that the electron density, charge density, and electron temperature increase with the frequency increase when radio frequency (RF) power is 40 W. The electron heating rate and argon ion heating rate near the sheath increase with the frequency increase. The high-energy electron density (> 3 0   eV) varies nonlinearly with the frequency increase. The high-energy electron density is highest at 80 MHz among the four frequencies. The electron density, charge density, and high-energy electron density increase with RF power (30, 45, 60, and 75 W) increase at 80 MHz. The electron temperature decreases with RF power increase at 80 MHz. The electron heating rate and argon ion heating rate near the sheath have no change with RF power increase at 80 MHz. The electron energy probability distributions (EEPF) show that the number of high-energy electrons (> 3 0   eV) is highest at 80 MHz. The reason may be the electron resonant heating that occurs in the plasma when the electron cyclotron frequency equals source frequency at 80 MHz. The electron dynamics of capacitively coupled plasma is important for microelectronics etching and membrane deposition. [ABSTRACT FROM AUTHOR]

The work reported in this paper addresses two aspects. In the first part, numerical simulations are conducted to examine the impact of magnetic equilibrium shaping (elongation and triangularity), on both conventional Ion Temperature Gradient (ITG) modes and Short Wavelength ITG modes. This analysis is performed considering the experimental profiles and parameters of the ADITYA-U tokamak, employing the nonlinear global gyrokinetic Particle-in-Cell code ORB5. The linear and nonlinear collisionless electrostatic simulation of these modes are carried out with kinetic ions and adiabatic electrons. From the linear results, it has been observed that the magnetic equilibrium shaping slighty reduced the growth rates and widened the spectrum, and the maxima of growth rate curve is shifted to higher toroidal wave number. We find that the heat flux is reduced by a significant ≃ 35 % for the true circular magnetohydrodynamic magnetic equilibrium as compared to ad hoc concentric circular equilibrium reported in Singh et al (2023 Nucl. Fusion 63 086029). A further ≃ 10 % reduction in the heat flux is seen with magnetic equilibrium shaping. In the second part, linear collisionless electrostatic simulation studies of ITG coupled with fully kinetic electrons (both trapped and passing electrons are treated kinetically) using a drift-kinetic ordering is performed. It can be seen from the linear results that, in presence of kinetic electrons, the growth rate and real frequency of the ITG mode are increased significantly for ADITYA-U parameters and a mode propagating in the electron diamagnetic direction is identified at high toroidal wavenumbers. [ABSTRACT FROM AUTHOR]

The sheath formation mechanism is modeled in a four-component collisional electronegative warm plasma considering the behavior of positive ions by fluid equations and of negative ions by the Boltzmann distribution, along with non-extensive distributions of hot and cold electrons. For a more realistic situation, the ion source term and the ionization rate are also included in the basic equations that are solved numerically by applying appropriate boundary conditions. A concept of sheath thickness measurement is established based on two approaches, namely, the zero-electron-density approach and the floating potential approach. An identical behavior of the sheath thickness is observed based on these approaches, which means that the floating potential approach confirms the efficacy of the zero-electron-density approach. Finally, the effects of various parameters such as the temperature of all the plasma species, collisions, ionization rate, and non-extensivity are evaluated on the profiles of the densities of plasma species, electric potential, and net space charge density for better understanding of the sheath formation mechanism. In comparison to electropositive plasma, a sharp fall in the potential for the case of electronegative plasma has been depicted, or in other words, higher potential gradient is realized in the electronegative plasma. Also, increasing negative ion temperature results in the reduced sheath thickness and produces a stronger gradient in the potential. [ABSTRACT FROM AUTHOR]

Modification of the solar wind parameters at the bow shock (BS) and through the magnetosheath (MSH) is essential for the solar wind-magnetosphere interaction chain. The present study uses two approaches to determine the spatial profile of magnetic field strength and plasma parameters and their fluctuations along the Sun-Earth line under different interplanetary magnetic field (IMF) orientations with an emphasis on radial IMF conditions. The first method is based on the superposed epoch analysis of all the complete THEMIS MSH crossings between 2007 and 2010. The second approach uses the distance of the observing spacecraft from the model magnetopause (MP) expressed in units of an MSH thickness for all THEMIS observations. The results of both these analyses are consistent, and their comparison with simulations reveals the following features: 1) the sign of the IMF north-south component has a negligible effect on the spatial profile of the magnetic field strength or plasma parameters as well as on the level of fluctuations; 2) the ion temperature is enhanced for a radial MF and it is nearly isotropic throughout MSH; 3) the fluctuation level of plasma parameters just downstream BS is enhanced under a radial IMF, but it gradually decreases toward MP to a value typical for other IMF orientations; 4) magnetic field fluctuations are enhanced by a factor of 1.7 in the whole magnetosheath when IMF points radially. [ABSTRACT FROM AUTHOR]

The lanthanum sulfide γ-La 2 S 3 with cubic Th 3 P 4 structure has emerged as a promising long-wave infrared transparent material. However, the γ-La 2 S 3 is only stable at high temperatures (>1300 °C). In this work, a novel method to lower the stabilization temperature is reported. Bivalent Ba ions are incorporated into the La 2 S 3 crystal structure and the stabilization temperature of the γ-La 2 S 3 decreased to less than 850 °C. The Ba2+-doped γ-La 2 S 3 (γ-La 2 S 3 : Ba2+) was successfully developed using the coprecipitation reaction method and sulfidation with CS 2. The high phase purity, good thermal stability, and lowest oxide sulfide impurities were obtained by Ba/La = 0.1 (in mole, abbreviated as n Ba/La = 0.1). The first-principles calculation shows that the theoretical E g of the prepared γ-La 2 S 3 : Ba2+ was 2.94 eV, which matched well with the experimental data. The energy band structure and density of states of the synthesized γ-La 2 S 3 : Ba2+ powder indicated that it was an indirect semiconductor which could be employed as a raw material for preparing infrared transparent optical ceramics. [ABSTRACT FROM AUTHOR]

By employing Bayesian inference techniques, the full electron density profile from the plasma core to the edge of Wendelstein 7-X (W7-X) is inferred solely from neutral hydrogen beam and halo Balmer- α (H α) emission data. The halo is a cloud of neutrals forming in the vicinity of the injected neutral beam due to multiple charge exchange reactions. W7-X is equipped with several neutral hydrogen beam heating sources and an H α spectroscopy system that views these sources from different angles and penetration depths in the plasma. As the beam and halo emission form complex spectra for each spatial point that are non-linearly dependent on the plasma density profile and other parameters, a complete model from the neutral beam injection and halo formation through to the spectroscopic measurements is required. The model is used here to infer electron density profiles for a range of common W7-X plasma scenarios. The inferred profiles show good agreement with profiles determined by the Thomson scattering and interferometry diagnostics across a broad range of absolute densities without any changes to the input or fitting parameters. The time evolution of the density profile in a discharge with continuous core density peaking is successfully reconstructed, demonstrating sufficient spatial resolution to infer strongly shaped profiles. Furthermore, it is shown as a proof of concept that the model is also able to infer the main ion temperature profile using the same data set. [ABSTRACT FROM AUTHOR]

The advanced fast ion-dominated high beta plasma is achieved using multi-MW neutral heating beams. To facilitate the diagnostics of this fast ion-dominated plasma, a high-energy and high-current diagnostic neutral beam (DNB) injector was designed and built by the Budker Institute of Nuclear Physics. The DNB injector made active measurements of ion temperature and rotational velocity possible with the help of charge-exchange spectroscopy for impurity ions and, most importantly, for the main ion (deuterium) component. A DNB energy of 40 keV was chosen to assure low beam attenuation in the plasma and to enable spectroscopic measurements along the entire plasma column. The diameter (level 1/e) of the ballistically focused DNB in the plasma is about 8 cm. To achieve a high temporal resolution, unique methods of beam modulation with a frequency of up to 10 kHz were implemented. The achieved high DNB current of 8 A in atomic hydrogen in combination with the beam modulation enables to obtain an acceptable signal-to-noise ratio of the measured spectra. [ABSTRACT FROM AUTHOR]

The nonlinear propagation of small amplitude dust acoustic solitary waves (DASWs) in a magnetized dusty plasma, containing Boltzmann distributed electrons of two distinct temperatures (low and high electron temperatures), negatively charged dust particles, and ions with two distinct temperatures (low and high ion temperatures) following Boltzmann distribution, is studied by deriving the Korteweg–de Vries (K–dV) equation. It is found that the characteristics of DASWs are significantly modified by two different temperature electrons (as well as ions), the external magnetic field, obliqueness of the system, and the number densities of two types of ions. It is shown that both compressive and rarefactive dust acoustic solitons occur in this case. [ABSTRACT FROM AUTHOR]

Microturbulence in magnetic confined plasmas contributes to energy exchange between particles of different species as well as the particle and heat fluxes. Although the effect of turbulent energy exchange has not been considered significant in previous studies, it is anticipated to have a greater impact than collisional energy exchange in low collisional plasmas such as those in future fusion reactors. In this study, gyrokinetic simulations are performed to evaluate the energy exchange due to ion temperature gradient (ITG) turbulence in a tokamak configuration. The energy exchange due to the ITG turbulence mainly consists of the cooling of ions in the ∇ B -curvature drift motion and the heating of electrons streaming along a field line. It is found that the ITG turbulence transfers energy from ions to electrons regardless of whether the ions or electrons are hotter, which is in marked contrast to the energy transfer by Coulomb collisions. This implies that the ITG turbulence should be suppressed from the viewpoint of sustaining the high ion temperature required for fusion reactions since it prevents energy transfer from alpha-heated electrons to ions as well as enhancing ion heat transport toward the outside of the reactor. Furthermore, linear and nonlinear simulation analyses confirm the feasibility of quasilinear modeling for predicting the turbulent energy exchange in addition to the particle and heat fluxes. [ABSTRACT FROM AUTHOR]

We investigate the core confinement properties of two recently devised quasi-helically symmetric stellarator configurations, HSK and QSTK. Both have been optimized for large critical gradients of the ion temperature gradient mode, which is an important driver of turbulent transport in magnetic confinement fusion devices. To predict the resulting core plasma profiles, assuming a fixed edge temperature, we utilize an advanced theoretical framework based on the gyrokinetic codes GENE and GENE-3D, coupled to the transport code TANGO. Compared to the HSX stellarator, both HSK and QSTK achieve significantly higher core-to-edge temperature ratios, partly thanks to their smaller aspect ratios, with the other part due to more detailed shaping of the magnetic geometry achieved during optimization. The computed core confinement time, however, is less sensitive to core temperature than the fixed edge temperature, simply due to the disproportionate influence, the edge has on stored plasma energy. We, therefore, emphasize the possible benefits of further optimizing turbulence in the outer core region, and the need to include accurate modeling of confinement in the edge region in order to assess overall plasma performance of turbulence optimized stellarators. [ABSTRACT FROM AUTHOR]

The study investigates alterations in the mechanical and thermophysical properties of ceramics composed of xLi2ZrO3–(1−x)Li4SiO4 as radiation damage accumulates, mainly linked to helium agglomeration in the surface layer. This research is motivated by the potential to develop lithium-containing ceramics characterized by exceptional strength properties and a resistance to the accumulation of radiation damage and ensuing deformation distortions in the near-surface layer. The study of the radiation damage accumulation processes in the near-surface layer was conducted through intense irradiation of ceramics using He2+ ions at a temperature of 700 °C, simulating conditions closely resembling operation conditions. Following this, a correlation between the accumulation of structural modifications (value of atomic displacements) and variations in strength and thermophysical characteristics was established. During the research, it was observed that two-component ceramics exhibit significantly greater resistance to external influences and damage accumulation related to radiation exposure compared to their single-component counterparts. Furthermore, the composition that provides the highest resistance to softening in two-component ceramics is an equal ratio of the components of 0.5Li2ZrO3–0.5Li4SiO4 ceramics. [ABSTRACT FROM AUTHOR]

Based on correlated magnetosphere‐ionosphere (M‐I) conjugate observations of seven events, we study the hot zone developed under short‐circuiting conditions leading (a) to the development of outward Subauroral Polarization Streams (SAPS) or Subauroral Ion Drifts (SAID) electric (E) field and (b) to the various subauroral arcs' absence or presence. Results show (a) the close relations of the hot zone earthward extent and peak ion temperature (Ti) to the magnitude of outward SAPS/SAID E field and (b) the hot zone's high Ti (∼11,000 eV) developed under enhanced plasma turbulence that was (c) generated by the amplified narrow hot ion and electron plasma density peaks, (d) sometimes in plasmaspheric plumes, and that was (e) sometimes further enhanced by the strong auroral kilometric radiation (AKR) waves (f) leading to the development of enhanced SAPS/SAID E field. From these (a–f) findings we conclude for the seven events investigated that (a) the hot zone's development under short‐circuiting conditions was regulated by the kinetic energy of mesoscale plasma flows and that (b) the hot zone created the favorable inner‐magnetosphere conditions during short circuiting (c) for stable auroral red (SAR) arc development by plasma turbulence, which is the common source of heat/suprathermal particles accelerated downward, and (d) in the plasmaspheric plume scenario for SAR arc and Strong Thermal Emission Velocity Enhancement (STEVE) arc development by the plumes' enhanced cold plasma populations leading to strong shear flows and thus shear‐flow instabilities well‐known associated with the SAPS/SAR arc and recently regarded as a potential driver mechanism of the STEVE arc. Key Points: The hot zone's development under short‐circuiting conditions was regulated by the kinetic energy of mesoscale plasma flowsThe hot zone created favorable inner‐magnetosphere conditions for the development of stable auroral red arc by plasma turbulenceStrong Thermal Emission Velocity Enhancement arc development was favored by the plasmaspheric plume related shear flows [ABSTRACT FROM AUTHOR]

The presented paper discusses the production of radioactive ion beams of francium, radium, and actinium from thick uranium carbide (UC x ) targets at ISOLDE, CERN. This study focuses on the release curves and extractable yields of francium, radium and actinium isotopes. The ion source temperature was varied in order to study the relative contributions of surface and laser ionization to the production of the actinium ion beams. The experimental results are presented in the form of release parameters. Representative extractable yields per μ C are presented for 222 - 231 Ac, several Ra and Fr isotopes in the mass ranges 214 ≤ A ≤ 233 and 205 ≤ A ≤ 231 respectively. The release efficiency for several isotopes of each of the studied elements was calculated by comparing their yields to the estimated in-target production rates modeled by CERN-FLUKA. The maximal extraction efficiency of actinium was calculated to be 2.1(6)% for a combination of surface ionization using a Ta ion source and resonant laser ionization using the two-step 438.58 nm, and 424.69 nm scheme. [ABSTRACT FROM AUTHOR]

The electron/ion density/temperature and ion velocities observed by the ROCSAT-1 and DEMETER satellites are used to examine the daytime wavenumber-4 (WN4) feature in the equatorial/low latitude ionosphere during various months and solar activity levels of 1999–2010. A moving median process has been employed to isolate WN4 features and calculate their amplitudes, while the upward ion drift is used to estimate electric fields. The ROCSAT-1 and DEMETER ion density, ion temperature, and ion velocity generally yield prominent WN4 features over the center of Pacific Ocean, the west side of South America, the center of the Atlantic Ocean, and Southern India. The correlation coefficient between the deviation of ion density and upward ion drift is significant during high solar activity of 1999–2004, while it approaches to zero during low solar activity of 2004–2010. This confirms that the longitudinal variation of the upward ion drift is essential during high solar activity, and the associated amplitude of dynamo eastward electric field is in the range of 0.10–0.14 mV/m, which is 15–19% of daily dynamo electric field. By contrast, the deviation of the ion density and the northward field-aligned ion flow show a clear anti-correlation which yields a maximum coefficient in August during low solar activity but no correlation during high solar activity. These indicate that the longitudinal variation of the meridional field-aligned ion flow could play an important role during low solar activity, and its amplitude is in the range of 10.44–13.91 m/s, which is 10–13% of the ambient ion flows. [ABSTRACT FROM AUTHOR]

The article presents the results of numerical modeling and experimental studies of the dynamics of temperature fields on the aluminum sample surface after a short repetitively-pulsed energy impact on the surface, and at the synergy of high-intensity titanium ion implantation into aluminum with a simultaneous repetitively-pulsed energy impact of the beam on the surface. The data on the accumulation and spatial distribution of implanted titanium in aluminum are presented. Using the samples heated by a repetitively-pulsed ion beam to the temperatures of 300°C and 500°C with an additional heating during each pulse to a temperature approaching that of melting, a possibility of ion doping of aluminum with titanium to the depths of up to 5 and 8 μm, respectively, is shown. [ABSTRACT FROM AUTHOR]

We present a stellarator configuration optimized for a large threshold ('critical gradient') for the onset of the ion temperature gradient (ITG) driven mode, which achieves the largest critical gradient we have seen in any stellarator. Above this threshold, gyrokinetic simulations show that the configuration has low turbulence levels over an experimentally relevant range of the drive strength. The applied optimization seeks to maximize the drift curvature, leading to enhanced local-shear stabilization of toroidal ITG modes, and the associated turbulence. These benefits are combined with excellent quasi-symmetry, yielding low neoclassical transport and vanishingly small alpha particle losses. Analysis of the resulting configuration suggests a trade-off between magnetohydrodynamic (MHD) and ITG stability, as the new configuration possesses a vacuum magnetic hill. [ABSTRACT FROM AUTHOR]

An approximate modeling of the low- to high-confinement (L-H) transition dynamics is given using the method, similar to that by Hinton et al. [Phys. Fluid B 5, 1281 (1993)], but considering more explicitly the L-mode edge turbulence which is here assumed to be dominated by the resistive ballooning mode (RBM) near the separatrix, while the ion temperature gradient (ITG) mode in the inner edge–core region. It is shown that the L-H transition can then be initiated from an inner edge near the ITG-RBM transition point with a finite width. Especially, this width is found to have a strong edge safety-factor or poloidal field dependence, similar to that shown by the EPED1 model. Meanwhile, unlike the pedestal width, the H-mode threshold power appears to be much less sensitive to the edge safety-factor, in qualitative agreement with the observed weak dependence of the threshold power on plasma current (IP). From an additional brief check, these dependences on IP are also found to be quite different from the behavior of other parameters (ion mass, toroidal field, plasma density, and effective Z-number) where the threshold power depends relatively strongly while the initial width depends somewhat weakly on most of them, except the effective Z-number. [ABSTRACT FROM AUTHOR]

This work reports on recent results on the search for high performance plasma scenarios at the magnetically confined stellarator fusion device Wendelstein 7-X. In four new designed scenarios, the development from transient toward stationary plasmas of improved performance has been realized. In particular, a high performance duration of up to 5 s, an energy confinement time of 0.3 s, a diamagnetic energy of 1.1 MJ, a central ion temperature of 2.2 keV, and a fusion triple product of 3.4 × 10 19 m − 3 · keV · s have been achieved, and previously observed limitations of the machine have been overcome, regarding both the performance and its duration. The two main experimental techniques for stationary high performance are neutral beam injection core fueling on the one hand and the use of a magnetic field configuration with internal islands on the other hand. Two of the developed scenarios are expected to be extendable straightforward toward a duration of several tens of seconds, making use of the long pulse operation capabilities of W7-X. [ABSTRACT FROM AUTHOR]

An alternative local electrostatic gyrokinetic eigenvalue code is developed for the ion-temperature-gradient-driven mode, the trapped-electron mode (TEM), and the electron-temperature-gradient (ETG)-driven mode. It numerically solves the linear eigenvalue problem for the electrostatic drift waves in the Fourier transformed space and benchmarks well with the HD-7 code and FULL code. The linear ETG and TEM instabilities in the electron thermal internal transport barrier (eITB) with dominant electron heating in experimental advanced superconducting tokamak are analyzed by using this code. The linear analysis results are consistent with that from the critical electron-temperature-gradient threshold analysis. Moreover, the sensitivity of ETG and TEM instabilities to parameters during the eITB formation has been investigated. For the typical eITB discharge, it is found that the instability of ETG mode is more sensitive to the stabilizing effect of the electron–ion temperature ratio (τe), while the instability of TEM is more sensitive to the destabilizing effect of η e . In addition, mixing length estimation of the turbulent transport in the eITB is also discussed, which suggests that the TEM may be saturated by other nonlinear effects than the resonance broadening. [ABSTRACT FROM AUTHOR]

The ion kinetic effect on the formation of intense laser-driven collisional shock waves is investigated via hybrid fluid-particle-in-cell simulations. It is found that the ion heat flux dominates the shock formation, which is considerably larger than the electron heat flux in the shock region. The rise of the temperature due to the laser energy deposition drives a heatwave into the overdense plasma, creating an electron–ion energy exchange zone between the critical surface and heat wave front. The heated ions, which are generated at the electron–ion energy exchange zone via the friction force, are found to travel to the high-density region and cause a tail distribution gain. Despite the small quantity, the heated tail ions contribute most of the ion heat flux during the shock formation. Additionally, as the electron heat flux decreases, the population of the heated tail ions is reduced, leading to a fall in the ion heat flux. This results in the delay or even suppression of the shock formation, because the ions are in a non-equilibrium state in the vicinity of the shock region, the ratio of the downstream ion temperature to the upstream ion temperature tends to a modestly decrease in comparison to the theory. The study provides a clear picture of the formation process of laser-driven shock waves. [ABSTRACT FROM AUTHOR]

Porous polyethylene glycol terephthalate (PET) film is a kind of mesopore structure template with pore size ranging from nanometer to micrometer by chemical etching after irradiation of heavy ions. The etching rate is an important factor affecting the pore morphology and quality of the membrane. In this paper, four stacked PET film were irradiated with 140 MeV 32S ions at room temperature and vacuum. During chemical etching of irradiated samples, the path etching rate Vt was determined by conduction method, and the bulk etching rate Vb was determined by weighing method. The relationship between etching temperature, concentration, sensitization time, and etching rate was studied. The results show that the etching rate is exponentially correlated with the etching temperature, and increases linearly with the increase of the etching solution concentration. When the concentration of NaOH is 3 mol·L−1 and the etching temperature is 75°C, the formation of cylindrical micropores is the most favorable. The pore size of porous PET film can be adjusted, and the relationship between pore size and etching time is dnm=15nm+0.24t. This is of great significance for the preparation of nanowires with uniform size and stable properties. Highlights: We have obtained the optimal conditions for obtaining cylindrical holes.The relationship between the diameter of holes and etching time were determined. [ABSTRACT FROM AUTHOR]

We present the first direct evidence of an in situ excitation of drift‐compressional waves driven by drift resonance with ring current protons in the magnetosphere. Compressional Pc4–5 waves with frequencies of 4–12 mHz were observed by the Arase satellite near the magnetic equator at L ∼ 6 in the evening sector on 19 November 2018. Estimated azimuthal wave numbers (m) ranged from −100 to −130. The observed frequency was consistent with that calculated using the drift‐compressional mode theory, whereas the plasma anisotropy was too small to excite the drift‐mirror mode. We discovered that the energy source of the wave was a drift resonance instability, which was generated by the negative radial gradient in a proton phase space density at 20–25 keV. This proton distribution is attributed to a temporal variation of the electric field, which formed the observed multiple‐nose structures of ring current protons. Plain Language Summary: During magnetic storms and substorms, energetic ions are sporadically injected into the geospace, which distorts the stable population and velocity distributions of ions in space. At these moments, various plasma instabilities lead to ultra‐low frequency (ULF) wave excitations. The lowest‐frequency waves in the ULF range have a wavelength comparable to the size of the Earth and are typically analyzed using magnetohydrodynamic principles. This approach considers the plasma environment using macroscale parameters such as pressure and density. In this paper, we report a spacecraft observation of a broadband compressional ULF wave that cannot be interpreted using magnetohydrodynamics. Such waves have rarely been reported and analyzed; however, their interaction with energetic ions is important to understand magnetospheric energy dynamics. The plasma conditions were described using the kinetic theory, which involves particle velocity distributions. We observed that a drift resonance occurred between the energetic protons and waves, while the gradient instability condition was satisfied for a part of time. Therefore, we concluded that the wave was in a drift‐compressional mode excited through drift resonance and gradient instability. The interpretation of compressional waves via satellite observations of energetic ions has been receiving increasing attention to understand their excitation mechanism. Key Points: Pc4–5 compressional ultra‐low frequency waves with an azimuthal wave number of −130 were observed in the nose structure on dusksideTheoretically predicted values of drift‐compressional mode frequency match the observed wave frequencyBoth radial ion temperature gradient and drift resonance of 20–25 keV protons serve as energy sources of the wave [ABSTRACT FROM AUTHOR]

The solid electrolyte Li10GeP2S12 (LGPS) plays a crucial role in the development of all-solid-state batteries and has been widely studied both experimentally and theoretically. The properties of solid electrolytes, such as thermodynamic stability, conductivity, band gap, and more, are closely related to their ground-state structures. However, the presence of site-disordered co-occupancy of Ge/P and defective fractional occupancy of lithium ions results in an exceptionally large number of possible atomic configurations (structures). Currently, the electrostatic energy criterion is widely used to screen favorable candidates and reduce computational costs in first-principles calculations. In this study, we employ the machine learning- and active-learning-based LAsou method, in combination with first-principles calculations, to efficiently predict the most stable configuration of LGPS as reported in the literature. Then, we investigate the diffusion properties of Li ions within the temperature range of 500–900 K using ab initio molecular dynamics. The results demonstrate that the atomic configurations with different skeletons and Li ion distributions significantly affect the Li ions' diffusion. Moreover, the results also suggest that the LAsou method is valuable for refining experimental crystal structures, accelerating theoretical calculations, and facilitating the design of new solid electrolyte materials in the future. [ABSTRACT FROM AUTHOR]

The current study investigates the thermophysical properties, including density, dynamic viscosity, and kinematic viscosity, of a zwitterionic surfactant, namely 3-(N,N–dimethylmyristylammonio)propane sulfonate (DMPS), in aqueous solutions both with and without electrolytes (specifically halide ions), within the temperature range of 293 to 333 K with 5 K gap. For the pure zwitterionic surfactant, a decreasing trend was observed in dynamic viscosity, density, and kinematic viscosity with rising temperature. However, in the presence of halide ions (salt), an increase in their concentration led to rising values of thermophysical properties. Nonetheless, akin to the pure surfactant, a declining trend was noted with rising temperature with electrolytes (halide ions). The efficacy of halide ions followed order: F– ˂ Cl– ˂ Br–. Additionally, the activation energy of the surfactant (DMPS) was assessed both with and without halide ions (electrolytes). Analysis through Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance spectroscopy (1H NMR) confirmed physical interactions between the surfactant DMPS and halide ions in the solutions. No evidence of chemical reactions or complex formations was observed during this interaction. [ABSTRACT FROM AUTHOR]

Collective Thomson scattering (TS) is a powerful technique to accurately diagnose the parameters of laser-produced plasmas. However, when the scattering parameter α, which is inverse to the product of electron Debye length and wavenumber of plasma fluctuations, is significantly larger than 1, which of the conditions is easily satisfied in the experiment, the accuracy of electron density measurement is usually poor just with the single-wavenumber ion-acoustic wave feature of the TS spectrum. This situation can be greatly improved in the imaging TS experiment because the signal intensity is proportional to electron density. A novel algorithm is developed and validated for the data analysis of imaging TS through the combination of signal intensity and spectral profile. The results show that we can obtain the electron density with high confidence, as well as other plasma parameters like electron and ion temperatures. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A one-dimensional model, in which the ionization and collision are omitted in the Debye sheath region, is applied to investigate the effect of the superthermal electrons on the heat flux through a magnetized sheath. For different temperatures and concentrations of the superthermal electron, and magnitudes and directions of the magnetic field, the profiles of plasma parameters including ion density and flow velocity perpendicular to the wall, the background and superthermal electron densities, and sheath potential in the presheath region are calculated. The variation of the plasma density and sheath potential drop at the Debye sheath entrance with the superthermal electrons and magnetic field modifies the particle and heat fluxes across the Debye sheath to the material surface. The sheath heat transmission coefficient can increase significantly even for a very small superthermal electron population. The dependence of the sheath heat transmission coefficient on the magnetic field angle decreases with the contribution of the superthermal electron in a strong magnetized sheath. When investigation of the heat flux including the superthermal electrons to a water-cooled W/Cu monoblack for the tokamak divertor, compared to the case of without superthermal electrons, it is found that the increase in both heat flux to the material surface and surface temperature of the material is mainly due to the enhancement of the sheath potential drop caused by the superthermal electrons, but the increase in the latter is not as pronounced as the former. [ABSTRACT FROM AUTHOR]