Hall Accelerator Research Articles

Hall current and Dufour effect on the flow of a viscous fluid in the presence of suction, chemical reaction, and heat source: Laplace transform procedure

AbstractThe present investigation explores the transient magnetohydrodynamics gravity‐driven flow of a viscous, incompressible, electrically conducting fluid past a permeable exponentially accelerated vertical plate in the presence of thermal radiation and suction. Due to several applications in different areas, the influence of Hall current, Dufour number, heat source parameter, and chemically reactive species diffusion are vital and are incorporated in the study, which is the novelty of the present work. The model equations are derived and resolved by utilizing an analytical technique called the Laplace transform procedure. Various properties of the flow due to the influence of different vital parameters have been depicted with the help of graphs. The computed gradients of velocity, temperature and concentration are presented in tabular form. The Hall parameter is observed to strengthen the secondary flow while diminishing the primary flow. Dufour number and heat source parameter enhance the fluid temperature and velocity profiles while the heat sink declines them. Enhancement of the acceleration parameter significantly amplifies the primary skin friction coefficient. Suction boosts the heat transport as well as the mass transport rates at the surface of the plate, whereas injection declines them. Further, the Dufour number causes a significant reduction in the Nusselt number and magnitude of the secondary skin friction coefficient. The practical applications of the current research are the design of aircraft, cooling of microchips, Hall accelerators, separation of isotopes and many more.

Hall Current and Viscous Dissipation Impact on MHD Mixed Convection Flow towards a Porous Exponentially Surface with its Engineering Applications

Power generators, Hall accelerators, and flight MHD all require high levels of Hall current. The influence of Hall current and viscous dissipation on time-independent hydro-magnetic mixed convective radiative flow across a porous heated surface has thus been investigated using numerical computing and mathematical modeling in the current study. The fluid is electrically conducted and varies exponentially. It is assumed that the wall temperature and elongation rate will vary with specific exponential shapes. A solid uniform magnetic field BSUB0/SUB is employed normally to the surface. The mathematical model of PDEs for incompressible flow is transformed into ODE by applying a numerical technique based on a finite-difference structure which includes a three-stage Lobatto IIIa scheme with the help of MATLAB. The obtained solution depends on the convergence constraints involving the radiation parameter R, magnetic parameter M, porosity parameter Ω, Hall parameter m, buoyancy parameter ε, temperature distribution parameter a, Eckert number ESUBc/SUB, Prandtl number PSUBr/SUB, and convective term bh. Graphs of the velocity and temperature profiles are explained via pertinent parameters. Skin friction factor, and Nusselt number are also evaluated and presented graphically and in tabular form. Results clarify that temperature profile reduces by increasing values of temperature distribution parameter whereas opposite behavior is noted for positive values of the buoyancy parameter.

Mathematical modeling of MHD flow and radiative heat transfer past a moving porous rotating disk with Hall effect

PurposeThe present study aims to investigate the effect of radiation on the unsteady magnetohydrodynamic (MHD) flow of a viscous, electrically conducting Newtonian fluid over rotating disk moving upward/downward immersed in a porous medium, considering the Hall effect. The study is motivated by the various applications in the context of solar power technology, electric power generation, Hall accelerators, MHDs generators and other industrial areas when the fluid flow is subjected to the previously mentioned effects such as MHD, Hall effect and thermal radiation.Design/methodology/approachSuitable similarity transformations are employed to reduce the governing nonlinear partial differential equations into the nonlinear ordinary ones. The solutions of the reduced system are numerically obtained using the boundary value problem (BVP) Midrich scheme in Maple. The results are presented graphically for vertical disk movement, magnetic parameter, Hall current, Darcy parameter, thermal radiation and Schmidt number. Skin frictions, mass and heat transfer rates are numerically tabulated.FindingsIt is revealed that the vertical motion of the disk significantly boosts the radial and annular flows. Moreover, the Hall parameter has contrasting effects on velocity profiles for the range of magnetic field but temperature field is oblivious of this behavior. It is observed that heat and mass transfer considerably enhance along vertical disk movement. Also magnetic field, temperature ratio and radiation parameter significantly enhance the temperature field, while reaction rate parameter and Schmidt number decrease the concentration profile. The current model is calibrated in its reduced form to an already published literature with good correlation to ensure the numerical scheme's validity.Originality/valueThis work is original within the best efforts of the authors.

Study of the enhancement factor and electron potential in the D (3He, p)4He reaction using deuterated metal targets TiD and ZrD

The study of thermonuclear reactions such as D(d, p)3H, D(d, n)3He, T(d, n)3He, 3He(d, p)4He, and D(3He, p)4He is of great interest in the field of astrophysics, as it affects the primordial nucleosynthesis, as well as issues of stellar dynamics. These reactions are also of interest in thermonuclear power engineering, in connection with the increased interest in the possibility of practical application of thermonuclear fusion. In this work, the analysis of the results obtained in the course of studying the reaction D(3He, p)4He was carried out. The results were obtained by us in previous works on deuterated metal targets ZrD and TiD with Miller indices [111] and [100]. There is a need to more precise study of the effects accompanying thermonuclear reactions at low astrophysical energies. The purpose of this work is to study the behavior of the screening potential [Formula: see text] and the reaction enhancement factor [Formula: see text], depending on the crystal structure of targets and the interaction energy. The studies were carried out on a Hall accelerator (Tomsk, TPU) in the energy range [Formula: see text]([Formula: see text][Formula: see text]keV in lab reference frame with a step of 2[Formula: see text]keV. Experiments have shown that in reactions using metal deuterated targets a similar effect as in reactions using gas targets was observed. Specifically, an electron screening effect was observed, which leads to an increase in the reaction cross-section with decreasing energy, and in case of metal target this effect becomes stronger.

Transient free convective hydromagnetic flow in an infinite vertical cylinder with Hall current and heat source/sink

AbstractThe analysis of hydromagnetic flow has been a concern of consideration for research scientists and engineers. In this treatise, the unsteady hydromagnetic free convective flow of an incompressible, viscous, and electrically conducting fluid and heat transfer in a vertical cylinder with Hall effects and transverse magnetic field, in the presence of heat source and sink, is studied. Exact solutions of dimensionless unsteady governing equations are obtained by using the Laplace transform technique. Transient fluid velocity and temperature field are depicted by graphs, whereas heat transfer rate, mass flux, and skin‐friction are computed in a tabular form for different physical parametric values, such as the source/sink parameter, Hall current parameter, Prandtl number, and Hartmann number. The valuable result from the investigation is that the Hall parameter slightly accelerates the fluid velocity and it provides resistance to the skin friction at the cylindrical surface. Moreover, it is noticeable that temperature as well as velocity enhances and finally gets to its steady state with time. To be noted, the Hall effects have been widely applied in numerous experimental engineering applications, such as constrictions of turbines, Hall accelerators, Hall sensors.

Evaluation of Skyshine from an Accelerator Facility: Dependence on Distance and Angle.

Neutron skyshine from Linac Coherent Light Source II 4 GeV electron beam operation at SLAC National Accelerator Laboratory can contribute to prompt radiation exposure to the public at distances far beyond the accelerator tunnel housing. One of the shielding design requirements at SLAC is that the annual dose to a member of the public is no more than 0.05 mSv y. This study uses Monte Carlo code FLUKA to simulate the generation of neutrons from 4 GeV electron beam losses on a thick copper target inside a generalized geometry of the Linac Coherent Light Source II Beam Transport Hall accelerator tunnel section. The effective dose from neutron skyshine was characterized as a function of both distance from the tunnel wall (up to 1 km away) and angle relative to the beam direction (between 0° and 180°). This new methodology for evaluating neutron skyshine dose is applicable to high-energy GeV-range electron accelerator facilities both at SLAC and elsewhere.

Features of Jeffrey fluid flow with Hall current: A spectral simulation

The Hall current in MHD flow stimulates substantial interest of researchers because of its wide role in many geophysical, astrophysical and fluid engineering situations (construction of turbines, Hall accelerator and centrifugal machines). Motivated by such wide applications, the present work reports the influence of Hall current and thermal radiation on the three-dimensional Jeffrey fluid flow over a stretching surface. In order to achieve similar solution of the governing equations, transformation technique is adopted. The mathematical model is numerically solved by using a spectral technique, namely successive linearisation method (SLM). To explore the feature of various factors, e.g. Hall current and thermal radiation, the variation of flow dominant parameters on the obtained profiles are carefully elucidated with graphs. It can be sensed from the obtained graphs that primary and secondary velocity increase, but, temperature reduces with the enhancement in Hall current. Radiation parameter has the tendency to increase the temperature of the fluid.

Determination of the enhancement factor and the electron screening potential in the $$\hbox {D}(^{{3}}\hbox {He}, \hbox {p})^{4}\hbox {He}$$ reaction using TiD targets

The study of fusion reactions $$\hbox {D}(\hbox {d}, \hbox {p})^{3}\hbox {H}$$, $$\hbox {D}(\hbox {d}, \hbox {n})^{3}\hbox {He}$$, $$\hbox {T}(\hbox {d}, \hbox {n})^{3}\hbox {He}$$, $$^{3}\hbox {He}(\hbox {d}, \hbox {p})^{4}\hbox {He}$$, and $$\hbox {D}(^{3}\hbox {He}, \hbox {p})^{4}\hbox {He}$$ at astrophysical energies is of interest for both basic and applied physics. These studied provide information on electron screening of nuclear reactions that provide important information on the role of electrons in reactions induced by deuterons, tritons, and nuclei of helium isotopes that proceed in reactors. The $$\hbox {D}(^{3}\hbox {He}, \hbox {p})^{4}\hbox {He}$$ reaction was investigated at the pulsed plasma Hall accelerator (Tomsk) in the $$^{{3}}\hbox {He}^{{+}}$$ ion energy range $$E_{\mathrm{He}} =16\div 34$$ keV (laboratory reference frame) with a step of 2 keV. The goal of this work was to determine experimentally the enhancement factor of the $$\hbox {D}(^{{3}}\hbox {He}, \hbox {p})^{{4}}\hbox {He}$$ reaction and the electron screening potential $$U_{\mathrm {e}}$$ using a TiD targets with Miller indices [111] and [100]. A strong impact of the target crystal structure on reaction enhancement factor was discovered. We believe that solid-state effects make the largest contribution to the behavior of the enhancement factor $$\hbox {D}(^{{3}}\hbox {He, p})^{{4}}\hbox {He}$$ of the reaction as a function of energy. One of these effects is the particle channeling in crystal structures. An unexpected increase of the enhancement factors for the $$\hbox {D}(^{{3}}\hbox {He, p})^{{4}}\hbox {He}$$ reaction in the energy range $$16\div 22$$ keV probably indicates the emergence of some new mechanism that increases the yield of the reaction with lowering energy.

Nonlinear Hall Acceleration and the Quantum Rectification Sum Rule.

Electrons moving in a Bloch band are known to acquire an anomalous Hall velocity proportional to the Berry curvature of the band which is responsible for the intrinsic linear Hall effect in materials with broken time-reversal symmetry. Here, we demonstrate that there is also an anomalous correction to the electron acceleration which is proportional to the Berry curvature dipole and is responsible for the nonlinear Hall effect recently discovered in materials with broken inversion symmetry. This allows us to uncover a deeper meaning of the Berry curvature dipole as a nonlinear version of the Drude weight that serves as a measurable order parameter for broken inversion symmetry in metals. We also derive a quantum rectification sum rule in time reversal invariant materials by showing that the integral over frequency of the rectification conductivity depends solely on the Berry connection and not on the band energies. The intraband spectral weight of this sum rule is exhausted by the Berry curvature dipole Drude-like peak, and the interband weight is also entirely controlled by the Berry connection. This sum rule opens a door to search for alternative photovoltaic technologies based on the Berry geometry of bands. We also describe the rectification properties of Weyl semimetals which are a promising platform to investigate these effects.

Influence of heat source/sink on MHD flow between vertical alternate conducting walls with Hall effect

The key object of this article is to present the impact of heat source/sink and Hall current on the completely advanced natural convection flow of a viscous incompressible and electrically conducting fluid through a vertical channel with the condition that one wall is conducting and other is non-conducting. The resulting system of non-dimensional linear equations has been examined with the help of theory of simultaneous differential equations. Finally, we have found the expressions for the fluid velocity, induced magnetic field and temperature field in the compact form. Also, we have derived the induced current density from induced magnetic field and with the help of velocity we found skin friction and rates of mass flow. The obtained results are presented through graphs for distinct values of the Hartmann number, Hall current and heat source/sink parameters. It is noted that the impact of the Hartmann number is to reduce the parts of the velocity and induced current density but improve the constituents of induced magnetic field. Further, the increase of the Hall current parameter leads to enhancement and reduces the primary and secondary constituents of the velocity and induced magnetic field respectively. The Hall current gives rise to a cross flow and the variable fluid properties have strong effects on the shear stress and the Nusselt number. Hall current is applicable in Hall accelerators, Hall effect sensors and constrictions of turbines, etc.

Acceleration of heavy ions in the hall accelerator

The process of acceleration of heavy ions in the Hall accelerator is studied. Numerical solutions of one – dimensional hydrodynamic equations describing a three-component system-neutral particles, electrons and ions-are obtained. Ions move in a collisionless manner and are accelerated by a self-consistent electric field, electrons diffuse across the magnetic field. The self-consistent field is calculated using the Poisson equation, and it is shown that there is no singularity when the ion velocity coincides with the ion sound velocity. It is also shown that there is a critical magnetic field above which it is impossible to propagate the ion flow.

MHD heat transfer two-ionized fluids flow between parallel plates with Hall currents

Abstract A theoretical attempt is made to investigate the effect of Hall current on temperature distribution in MHD two-fluid flow of ionized gases (plasma) through horizontal channel bounded by two parallel plates under the action of an applied transverse magnetic field. It is assumed that the magnetic Reynolds number is small. The fluids in the two regions are considered to be incompressible, immiscible and electrically conducting with different viscosities, electrical and thermal conductivities. The transport properties of the two fluids are taken as constant. The governing momentum and energy equations for two-fluids that flow in two regions are detailed when the temperature of the two plates are prescribed to be the same. The solution is carried out in two cases, that is, (1) when the plates are made of the non-conducting and (2) conducting materials. The profiles for temperature distribution and rate of heat transfer coefficients are plotted for different set of values of the governing parameters. The effect of parameters on the temperature distribution and rate of heat transfer coefficient is discussed. It is observed in the case of non-conducting plates that the temperature distribution is independent of the ratio of electron pressure to the total pressure which relies on this parameter for conducting plates. It is seen in the case of conducting plates that an increase in Hall parameter diminishes the temperature distribution in the two regions for fixed values of the remaining parameters (i.e., Hartmann number, viscosity ratio, height ratio, electrical conductivity ratio and the ratio of thermal conductivities). It is expected that this theoretical study may have some practical application to numerous diversified areas like geophysical flows, aerospace science, in particular, aerodynamic heating and in engineering applications such as MHD generators, Hall accelerators, in thermo-nuclear power reactors and so forth.

Investigation of the D(3He, p)4He Reaction in the Astrophysical Energy Region of 18–30 keV

The D(3He, p)4He reaction is first investigated in a solid target of deuterated zirconium (ZrD) in the 3He+ ion energy range EHe = 18–30 (E = 7.2−12.0keV keV in the center-of-mass system) with a step of 2 keV. The electron screening potential Ue = (617.8 ± 154.7) eV and the D(3He, p)4He reaction enhancement factors are experimentally determined in the given energy range. The measured electron screening potential is six times higher than in gaseous targets. This can be due to the ZrD lattice effects, which have not been studied either theoretically or experimentally so far. The D(3He, p)4He reaction has been investigated at the pulsed plasma Hall accelerator (Tomsk).

Pulsed ion hall accelerator for investigation of reactions between light nuclei in the astrophysical energy range

The factors defining the constraints on the current characteristics of the magnetically insulated ion diode (IDM) are considered. The specific current parameters close to the maximum possible ones are obtained for the particular IDM-40 design assigned for acceleration of light ions and investigation of nuclear reactions with small cross sections in the astrophysical energy range (2–40 keV) in the entrance channel. It is experimentally demonstrated that the chosen optimal operation conditions for IDM-40 units provide high stability of the parameters (energy distribution and composition of accelerated particle beams, degree of neutralization) of the accelerated particle flux, which increases during the working pulse.

Effect of pd and dd reactions enhancement in deuterides TiD2, ZrD2 and Ta2D in the astrophysical energy range

Investigation of the pd-and dd-reactions in the ultralow energy (~keV) range is of great interest in the aspect of nuclear physics and astrophysics for developing of correct models of burning and evolution of stars. This report presents compendium of experimental results obtained at the pulsed plasma Hall accelerator (TPU, Tomsk). Most of those results are new, such as • temperature dependence of the neutron yield in the D(d, n)3He reaction in the ZrD2, Ta2D, TiD2 • potentials of electron screening and respective dependence of astrophysical S-factors in the dd-reaction for the deuteron collision energy in the range of 3–6 keV, with ZrD2, Ta2D temperature in the range of 20–200°C [1] • characteristics of the reaction d(p, γ)3He in the ultralow collision proton-deuterons energy range of 4-13 keV [2, 3] in ZrD2, Ta2D and TiD2 • observation of the neutron yield enhancement in the reaction D(d, n)3He at the ultralow deuteron collision energy due to channeling of deuterons in microscopic TiD2 with a face-centered cubic lattice type TiD1.73, oriented in the [100] direction [4]. The report includes discussion and comparison of the collected experimental results with the global data and calculations.

Studying the D(p, γ)3He reaction in zirconium deuteride within the proton energy range of 9–35 keV

This work is dedicated to measuring the dependences of the effective cross section and the astrophysical S factor for the pd reaction that proceeds in zirconium deuteride upon the proton-deuteron collision energy within a range of 6.0–23.3 keV. The experiment was performed using the heavy-current plasma Hall accelerator at the National Research Tomsk Polytechnic University. The gamma quanta produced in the pd reaction with the energy of 5.5 MeV was recorded using eight scintillation spectrometers based on NaI(Tl) crystals (400 × 100 × 100 mm), which were located around the target. The result of this work coincides with the result of our previous work obtained within a range of proton-deuteron collision energies of 7.3–12.7 keV and agrees well with the result obtained by the LUNA collaboration with the use of the gaseous deuterium target.

Experimental observation of electron screening for the D(p, γ)3He nuclear reaction in titanium Deuteride TiD

Characteristics of the pd reaction (p + d → 3He + γ(5.5 MeV)) in titanium deuteride at astrophysical proton-deuteron collision energies ranging from 5.3 to 10.5 keV are investigated. Experiments are conducted on the pulsed plasma Hall accelerator at Tomsk Polytechnic University (Tomsk, Russia). The number of accelerated protons in a pulse 10 μs long is 5 × 1014 at a repetition rate of 7 × 10−2 Hz. Gamma rays with an energy of 5.5 MeV are recorded by eight detectors based on NaI(Tl) crystals (100 × 100 × 400 mm) arranged around the TiD target. The dependence of the astrophysical S factor for the pd reaction on the proton-deuteron collision energy and the electron screening potential of protons interacting with deuterons in titanium deuteride are measured for the first time.

Study of the d(p, γ)3He reaction at ultralow energies using a zirconium deuteride target

The mechanism for the d(p, γ)3He reaction in the region of ultralow proton–deuteron collision energies (6.67<E<12.67keV) is investigated using a target of zirconium deuteride. The experiment was carried out in the proton beam from the high-current pulsed Hall accelerator. Dependences of the astrophysical S-factor and the effective pd reaction cross section on the proton–deuteron collision energy are measured. The results are compared with the available literature data. The results of this work agree with the experimental results obtained by the LUNA collaboration with the target of gaseous deuterium.

Measuring the astrophysical S factors and the cross sections of the p(d, γ)3He reaction in the ultralow energy region using a zirconium deuteride target

The present paper is dedicated to the study of the p(d, γ)3He reaction mechanism with the use of a zirconium deuteride target at proton energies of 11–19 keV. The experiment has been carried out using a proton beam of a high-current pulsed Hall accelerator at the National Research Tomsk Polytechnic University. The dependences of the astrophysical S factor and the effective cross section of the pd reaction on the proton-deuteron collision energy are measured. The results were compared with the available data. The results detailed in the present work agree with the results of an experiment carried out by the LUNA collaboration with the use of a gaseous deuterium target.

Effect of ion‐slip current on the thermal instability of natural convection flow in a boundary layer flow past a horizontal flat plate

PurposeThe purpose of this paper is to study the effects of ion‐slip current and Hall current on the formation of longitudinal vortices in natural convection flow over a heated horizontal plate.Design/methodology/approachThe criterion on the position marking on the onset of longitudinal vortices is defined in the present paper. The results show that the onset position characterized by the Grashof number depends on the Prandtl number, the Reynolds number, the wave number, the Hall parameter, the ion‐slip parameter, and the Hartmann number.FindingsThe flow becomes more stable as the magnetic field increases. However, the destabilizing effect is found on the flow when the Hall and ion‐slip currents are presented.Research limitations/implicationsThe standard method of linear stability model is applied, with terms higher than first order in disturbance quantities being neglected.Practical implicationsThe problem of MHD natural convection flow with Hall and ion‐slip currents has many important engineering applications, e.g. power generators, Hall accelerators and flows in channels and ducts.Originality/valueThis study is to check the validity of the assumptions that the conditions of Hall and ion‐slip currents can be ignored.