Charged Gas Research Articles

The bulk electroviscous effect

Electroviscous stresses arise as hydrodynamic flows disturb the ionic (Debye) clouds that screen charged surfaces in electrolyte solutions. The contribution thereof to the effective bulk viscosity (also known as the second or volume viscosity) of two-phase suspensions is quantified here. Specifically, the bulk viscosity of two model suspensions is calculated: (1) a dilute dispersion of rigid charged spherical particles immersed in a compressible electrolyte that undergoes uniform dilatation and (2) a dilute suspension of charged gas bubbles expanding uniformly in an incompressible electrolyte. In both cases, it is assumed that the fluid flow only slightly drives the Debye cloud out of equilibrium, which formally requires that the ratio of the ion diffusion to flow time scales—a Peclet number—is small. For a suspension of rigid particles, the electroviscous contribution to the effective bulk viscosity is proportional to the particle volume fraction and decreases monotonically as the ratio of the particle radius to the Debye length increases. Similar behavior is well known for the electroviscous contribution to the effective shear viscosity of a dilute hard-sphere suspension; a quantitative comparison between the bulk and shear viscosities is made. In contrast, the electroviscous contribution to the bulk viscosity of a dilute suspension of bubbles is independent of the bubble volume fraction and attains a finite value in the limit of vanishing Debye length.

Kinetic treatment for the exact solution of the unsteady Rayleigh flow problem of a rarefied homogeneous charged gas bounded by an oscillating plate

The exact solution of the unsteady Rayleigh flow problem of a rarefied charged gas bounded by an oscillating plate has been made. For this purpose, we use the traveling wave solution method. The kinetic and the irreversible thermodynamic properties of the charged gas are presented from the molecular viewpoint. Our study is based on the solution of the Bhatnager–Gross–Krook (BGK) model of the Boltzmann kinetic equation, with the precision value of the electron–electron collision frequency. The BGK model equation coupled with Maxwell’s equations, for electron gas near an oscillating rigid plane, are solved. The distinction and comparisons between the perturbed and the equilibrium velocity distribution functions are illustrated. The ratios between the different contributions of the internal energy changes are predicted via the extended Gibbs equation for both diamagnetic and paramagnetic plasmas. The results are applied to a typical model of laboratory argon plasma.

Two-step condensation of the charged Bose gas

The condensation of the spinless ideal charged Bose gas in the presence of a magnetic field is revisited. The conventional approach is extended to include the macroscopic occupation of excited kinetic states lying in the lowest Landau level, which plays an essential role in the case of large magnetic fields. In that limit, signatures of two diffuse phase transitions (crossovers) appear in the specific heat. In particular, at temperatures lower than the cyclotron frequency, the system behaves as an effectively one-dimensional free boson system, with the specific heat equal to 1/2Nk(B) and a gradual condensation at lower temperatures.

Magnetic properties of charged spin-1 Bose gases with ferromagnetic coupling

The magnetic properties of a charged spin-1 Bose gas with ferromagnetic interactions are investigated within mean-field theory. It is shown that a competition between paramagnetism, diamagnetism and ferromagnetism exists in this system. It is shown that diamagnetism, being concerned with spontaneous magnetization, cannot exceed ferromagnetism in a very weak magnetic field. The critical value of reduced ferromagnetic coupling of the paramagnetic phase to ferromagnetic phase transition increases with increasing temperature. The Landé-factor g is introduced to describe the strength of the paramagnetic effect which comes from the spin degree of freedom. The magnetization density increases monotonically with g for fixed reduced ferromagnetic coupling as . In a weak magnetic field, ferromagnetism makes an immense contribution to the magnetization density. On the other hand, at a high magnetic field, the diamagnetism tends to saturate. Evidence for condensation can be seen in the magnetization density at a weak magnetic field.

Kinetic and thermodynamic treatment for the exact solution of the unsteady Rayleigh flow problem of a rarefied homogeneous charged gas

This article presents an exact and enhanced solution of the study in the previous paper [Can. J. Phys., 88 (2010), 501–511]. For this purpose, I use the traveling wave solution method instead of the small parameter method, which enables us to have the full exact solution without any cut-off from the value of variables. In addition, I use the accurate formula of the electron–electron collision frequency. I persist in avoiding the discontinuity in the solution caused by the Laplace transformation results, which is included in the previous study. In the present work, the kinetic and the irreversible thermodynamic properties of the charged gas are presented from the molecular viewpoint. Our study is based on the solution of the BGK (Bhatnager–Gross–Krook) model of the Boltzmann kinetic equation, with the precision value of the electron–electron collision frequency. The BGK model equation coupled with Maxwell's equations for electrons near a moving rigid plane are solved. The distinction and comparisons between the perturbed and the equilibrium velocity distribution functions are illustrated. The ratios between the different contributions of the internal energy changes are predicted via the extended Gibbs equation for both diamagnetic and paramagnetic plasmas. The results are applied to a typical model of laboratory argon plasma.

Kinetic and thermodynamic treatment for the Rayleigh flow problem of an inhomogeneous charged gas mixture

The extension of our previous paper [Can. J. Phys., 88 (2010), 501–511] has been made for an inhomogeneous charged rarefied gas mixture (two components plasma) instead of a single electron gas. In the present work, the kinetic and the irreversible thermodynamic properties of the plasma are presented from the molecular point of view. Our study is based on the solution of the BGK (Bhatnager–Gross–Krook) model of the Boltzmann kinetic equation together with the Maxwell's equations for both positive ions and electrons in the vicinity of a moving rigid plane. The fundamental aim of this investigation is to illustrate the mutual effects caused by collisions on the distribution functions. The distinction and comparisons between the perturbed and the equilibrium velocity distribution functions are illustrated for both electrons and ions. The ratios between the different contributions of the internal energy changes are predicted via the Gibbs's equation for both diamagnetic and paramagnetic plasmas. The results are applied to a typical model of laboratory Argon plasma.

Kinetic and thermodynamic treatment for the exact solution of the unsteady Rayleigh flow problem of a rarefied homogeneous charged gas

This article presents an exact and enhanced solution of the study in the previous paper [Can. J. Phys., 88 (2010), 501–511]. For this purpose, I use the traveling wave solution method instead of the small parameter method, which enables us to have the full exact solution without any cut-off from the value of variables. In addition, I use the accurate formula of the electron–electron collision frequency. I persist in avoiding the discontinuity in the solution caused by the Laplace transformation results, which is included in the previous study. In the present work, the kinetic and the irreversible thermodynamic properties of the charged gas are presented from the molecular viewpoint. Our study is based on the solution of the BGK (Bhatnager–Gross–Krook) model of the Boltzmann kinetic equation, with the precision value of the electron–electron collision frequency. The BGK model equation coupled with Maxwell's equations for electrons near a moving rigid plane are solved. The distinction and comparisons between the perturbed and the equilibrium velocity distribution functions are illustrated. The ratios between the different contributions of the internal energy changes are predicted via the extended Gibbs equation for both diamagnetic and paramagnetic plasmas. The results are applied to a typical model of laboratory argon plasma.

Kinetic and thermodynamic treatment for the Rayleigh flow problem of an inhomogeneous charged gas mixture

The extension of our previous paper [Can. J. Phys., 88 (2010), 501–511] has been made for an inhomogeneous charged rarefied gas mixture (two components plasma) instead of a single electron gas. In the present work, the kinetic and the irreversible thermodynamic properties of the plasma are presented from the molecular point of view. Our study is based on the solution of the BGK (Bhatnager–Gross–Krook) model of the Boltzmann kinetic equation together with the Maxwell's equations for both positive ions and electrons in the vicinity of a moving rigid plane. The fundamental aim of this investigation is to illustrate the mutual effects caused by collisions on the distribution functions. The distinction and comparisons between the perturbed and the equilibrium velocity distribution functions are illustrated for both electrons and ions. The ratios between the different contributions of the internal energy changes are predicted via the Gibbs's equation for both diamagnetic and paramagnetic plasmas. The results are applied to a typical model of laboratory Argon plasma.

Combined electrospray ionization source with a velocity map imaging spectrometer for studying large gas phase molecular ions

We present a new compact and versatile experimental set-up that has been designed to perform electron and ion imaging experiments on large multiply charged gas phase molecular and cluster species. It combines an electrospray ionization source, a quadrupole mass filter guiding ion optics and a velocity map imaging spectrometer. Characterization of the spectrometer has been performed on atomic ions. Results obtained on molecular species (stilbene 420 dianions) demonstrate the possibility offered by this experimental set-up.

Kepler Predictor-Corrector Algorithm: Scattering Dynamics with One-Over-R Singular Potentials.

An accurate and efficient algorithm for dynamics simulations of particles with attractive 1/r singular potentials is introduced. The method is applied to semiclassical dynamics simulations of electron-proton scattering processes in the Wigner-transform time-dependent picture, showing excellent agreement with full quantum dynamics calculations. Rather than avoiding the singularity problem by using a pseudopotential, the algorithm predicts the outcome of close-encounter two-body collisions for the true 1/r potential by solving the Kepler problem analytically and corrects the trajectory for multiscattering with other particles in the system by using standard numerical techniques (e.g., velocity Verlet, or Gear Predictor corrector algorithms). The resulting integration is time-reversal symmetric and can be applied to the general multibody dynamics problem featuring close encounters as occur in electron-ion scattering events, in particle-antiparticle dynamics, as well as in classical simulations of charged interstellar gas dynamics and gravitational celestial mechanics.

Spectral probes of the holographic Fermi ground state: Dialing between the electron star and AdS Dirac hair

We argue that the electron star and the anti--de Sitter (AdS) Dirac hair solution are two limits of the free charged Fermi gas in AdS. Spectral functions of holographic duals to probe fermions in the background of electron stars have a free parameter that quantifies the number of constituent fermions that make up the charge and energy density characterizing the electron star solution. The strict electron star limit takes this number to be infinite. The Dirac hair solution is the limit where this number is unity. This is evident in the behavior of the distribution of holographically dual Fermi surfaces. As we decrease the number of constituents in a fixed electron star background the number of Fermi surfaces also decreases. An improved holographic Fermi ground state should be a configuration that shares the qualitative properties of both limits.

Development of intense high-energy noble gas ion beams from in-terminal ion injector of tandem accelerator using an ECR ion source

Abstract An ECRIS-based heavy ion injector was constructed in the high-voltage terminal of JAEA-Tokai Tandem Accelerator to develop new beam species of highly charged noble gas ions. This work was associated with a lot of development to operate the ion source on the 20UR Pelletron high voltage terminal in high pressure SF 6 gas environment. Highly charged ions of N, O, Ne, Ar, Kr and Xe have been accelerated satisfactorily. Operating data integrated during many years long beam delivery service are summarized.

Synthesis and Electrical Conductivity of La1−xSrxAl0.9Mg0.1O3−δ (x = 0.1–0.4) Perovskite Solid Solution

Perovskite solid solution powders of (La1−xSrx)(Al0.9Mg0.1)O3−δ (x = 0.1−0.4) were prepared by a coprecipitation method using corresponding aqueous solutions and ammonium carbonate solution. The X-ray diffraction patterns for the compositions of x = 0.1−0.4 were identified as those of hexagonal LaAlO3 solid solutions. The bulk conductivity of (La0.6Sr0.4) (Al0.9Mg0.1)O3−δ by AC method at 1 V was independent of the oxygen partial pressure and 2.33 ×10−3 Scm−1 at 800°C, suggesting the oxide ion conduction. The activation energy of bulk conductivity was 111 kJmol−1 at 300–500 °C. The grain boundary conductivity increased from 2.02×10−6 Scm−1 at Po2 = 10−15 Pa to 1.11×10−5 Scm−1 at Po2 = 2.1×104 Pa at 800 °C. Hole conduction contributed to the increased conductivity. DC conductivity of (La0.6Sr0.4)(Al0.9Mg0.1)O3−δ depended on the applied voltage and temperature. In N2 atmosphere, hole conductivity overlapped oxide ion conductivity at a high applied voltage (E > 1 V) because of the chemical reaction between positively charged oxide vacancy and N2 gas (Vo·· + N2 → 2No′ + 4h·).

Thermodynamics of Charged Ideal Bose Gases in a Trap under a Magnetic Field

We investigate thermodynamic properties of the rotating Bose gas in a trap, taking the charged ideal Bose gas in a magnetic field as an example. The system is equivalent to a neutral gas in a synthetic magnetic field. It is indicated that the Bose—Einstein condensation temperature is irrelevant to the magnetic field, conflicting with established intuition that the critical temperature decreases with the field increasing. The specific heat and Landau diamagnetization also exhibit intriguing behaviors.

Temporal Evolution of the Ion Fluxes for Various Elements in HIPIMS Plasma Discharge

In our previously published paper, the life span of metal ions in high-power impulse magnetron sputtering (HIPIMS) discharges was measured up to 5 ms from the start of the pulse. To investigate the influence of the ion mass, ionization energy, and sputter yield on the time evolution and life span of singly and doubly charged metal and gas ions in the HIPIMS plasma discharge, the most frequently used materials for thin-film deposition carbon, aluminium, titanium, chromium, copper, and niobium have been used. The ion energy distribution function of each material was measured using energy resolved mass spectrometry in time-resolved mode. The setup of the mass spectrometer was the same for all materials. To investigate the influence of working gas pressure on the time evolution of ion fluxes, measurements have been performed at two pressures, 0.3 Pa and 3 Pa.

Proposed relationship between the exponents γ and η at liquid–vapour critical point via the dimensionality d

In earlier work, Ma [S.K. MA, Phys. Rev. Lett., 29, 1311 (1972)] has studied the critical exponents γ and η for charged and neutral Bose gases. Here we use the result of Ma, valid for general dimensionality d but only to O(m −1), where m is the number of components of the Bose field, to write a relation between γ(d) and η(d) to O(m −1). This then motivates, but now for the Ising model, a relationship between the critical exponents γ and η, via the dimensionality d. We finally demonstrate a connection between the two renormalisation group eigenvalues y t and y h , via the critical exponent δ with a dimensional dependence.

Charged Brownian particles: Kramers and Smoluchowski equations and the hydrothermodynamical picture

We consider a charged Brownian gas under the influence of external and non-uniform electric, magnetic and mechanical fields, immersed in a non-uniform bath temperature. With the collision time as an expansion parameter, we study the solution to the associated Kramers equation, including a linear reactive term. To the first order we obtain the asymptotic (overdamped) regime, governed by transport equations, namely: for the particle density, a Smoluchowski-reactive like equation; for the particle’s momentum density, a generalized Ohm’s-like equation; and for the particle’s energy density, a Maxwell–Cattaneo-like equation. Defining a nonequilibrium temperature as the mean kinetic energy density, and introducing Boltzmann’s entropy density via the one particle distribution function, we present a complete thermohydrodynamical picture for a charged Brownian gas. We probe the validity of the local equilibrium approximation, Onsager relations, variational principles associated to the entropy production, and apply our results to: carrier transport in semiconductors, hot carriers and Brownian motors. Finally, we outline a method to incorporate non-linear reactive kinetics and a mean field approach to interacting Brownian particles.

Water Electrolyzers and the Zero-Point Energy

The gas emitted from popular water electrolyzer projects manifests unusual energetic anomalies, which include vaporizing tungsten when used in a welding torch and running internal combustion engines on small quantities of the gas. Some claim to run generators in closed loop fashion solely on the gas from the electrolyzer, which is powered solely from the generator. Most investigators believe the energy is from burning hydrogen. A hypothesis is proposed that the dominant energy is not coming from hydrogen, but rather it is coming from charged water gas clusters, which activate and coherently trap zero-point energy.

Cycle-to-Cycle Flow Rate Measurement on Reciprocating HCCI Engine Using Fast-Response Laminar Flow Meter

In recent years, higher thermal efficiency and lower emissions are required on a reciprocating engine development and therefore cycle-to-cycle combustion control is necessary. Especially it is a key factor to control HCCI combustion engine. In HCCI engine, one of the most promising combustion methods to achieve high thermal efficiency, the ignition timing strongly depends on the mass-averaged temperature of charged gas and residual gas and very precise combustion phase control is required. Therefore it is important to detect the changes of cycle-to-cycle intake air flow rate, EGR gas flow rate and as well as residual gas in each cycle. The traditional laminar flow meter has too low responsivity to measure cycle-to-cycle flow rate. In this study, the fast-response laminar flow meter was developed in order to measure cycle-to-cycle dynamical flow rate. The availability of the fast-response laminar flow meter for cycle-to-cycle intake air flow rate measurement of the HCCI engine is shown in this paper.

Diamagnetism versus paramagnetism in charged spin-1 Bose gases

It has been suggested that either the diamagnetism or paramagnetism of Bosegases, due to the charge or spin degrees of freedom respectively, appearssolely to be extraordinarily strong. We investigate the magnetic propertiesof charged spin-1 Bose gases in an external magnetic field, focusing on thecompetition between the diamagnetism and paramagnetism, using the Lande-factorg of particles to evaluate the strength of the paramagnetic effect. We propose that a gas with exhibits diamagnetism at all temperatures, while a gas withg > 1/2 always exhibits paramagnetism. Moreover, a gas with the Lande-factor in between shows ashift from paramagnetism to diamagnetism as the temperature decreases. Theparamagnetic and diamagnetic contributions to the total magnetization density are alsocalculated in order to demonstrate some details of the competition.