Parallel Electrode System Research Articles

Numerical Analysis of the Deformation of Aqueous Drop Under Uniform Electric Field

This article presents a numerical analysis of the deformation of an aqueous drop in an oil phase under electric field. The configuration of analysis is a sessile aqueous drop located on an electrode. We use the charge simulation method (CSM) to calculate the electric field in the configuration. The drop profile is determined by solving the augmented Young–Laplace equation. The solution is obtained by iteratively adjusting the drop contour and the fictitious charge for the CSM. Experiments were carried out to observe the behavior of an aqueous sessile drop in a parallel electrode system. The comparison between the experimental and numerical results shows a good agreement of the drop profiles for a wide range of the applied electric field. The calculated critical electric field of drop instability is lower than the value from the experiments by 4%. We employ the numerical analysis to clarify the effects of drop size, interfacial tension coefficient, and mass density of the oil phase on the deformation and the critical electric field of the aqueous drop.

On the Determination of the Initial Ignition Voltage of a Surface Discharge in Air

The experimental and calculated values of the initial ignition voltage of a surface barrier discharge in atmospheric air in a plane–parallel electrode system with a Plexiglas barrier are presented. It is shown that the calculation of the initial voltage based on a simplified procedure, in which the criterion of the discharge initiation is the realization of the Townsend condition, provides the calculated dependence of the initial voltage on the barrier thickness, which coincides with the experimental data.

Edge Vortex Flow Due to Inhomogeneous Ion Concentration

The ion distribution of an open parallel electrode system is not known even though it is often used to measure the electrical characteristics of an electrolyte. Thus, for an open electrode system, ...

Measurements and models of transient and stationary regimes of glow discharge in argon

The experimental and theoretical analyses of different regimes of argon DC glow discharge are reported. The experiments were carried out on the argon gas tube with a plane- parallel electrode system made from OFHC (oxygen-free high thermal conductivity) copper. Modelling of the static breakdown voltages was performed by simple fluid model. The applicability of fluid models for modelling of I - U (current-voltage) characteristics at different values of pd (pressure times inter-electrode distance) is tested. The formative time delays are determined from experiment and compared to modeled values obtained by [1D] and [2D] fluid models. The memory curve t̄d (τ) (the dependence of the mean value of breakdown time delay on the relaxation time) is presented and the main processes responsible for the memory effect were determined by applying the analytical and numerical models.

Water Treatment with Pulsed Plasmas Generated Inside Bubbles

Parallel operation of pulsed plasma generated inside bubbles is successfully demonstrated by applying fast rising voltage to a multi electrode system mounted in treat water. A 10 ppm acetic acid which is not decomposed by ozone is used as persistent materials in water and the decomposing efficiency of that material is evaluated by measuring TOC values in water. The electric conductivity of treat water affects the decomposing efficiency because the water resistor that is inversely proportional to the conductivity limits the plasma current flowing along the surface of bubbles that are generated by feeding oxygen gas. With nine parallel electrode system, the decomposing efficiency of acetic acid shows higher values than that with a single electrode system. The emission of OH radicals generated in plasma was observed by spectroscopic measurements.

Ion extraction from a laser-ionized plasma produced between parallel plate cathodes and an anode above them

We studied the behavior of a laser-photoionized plasma in atomic-vapor laser isotope separation under an external electric field with a two-dimensional one-fluid model, in which electrons are assumed to be in thermal equilibrium. Sheath-formation and ion-extraction processes are investigated in both a conventional parallel-electrode system and an M-type electrode system consisting of two parallel cathodes and one anode above them. The process of ion extraction in the M-type electrode was made clear and it is shown that ions are collected twice as fast as in the parallel-electrode system.

Detailed measurements and simplified modeling of wafer charging in different barrel reactor configurations

The detailed profiles of the wafer charging in different barrel reactor configurations have been obtained by using the electrically erasable–programmable read-only memory devices. Charging profile in a parallel electrode system depends strongly on the wafer orientation with respect to the rf electric field, while minor changes are observed by the use of floating Al etch tunnel and by the reduction of the wafer-to-wafer separation. On the other hand, no wafer charging is detected in a co-axial electrode system. A simplified equivalent circuit model, which represents the potential in 2-dimensional rf plasma–wafer system, has been proposed. The charging profile derived from the simplified model coincides with the experimental results. This model gives an analytical explanation of the gate charging.

An extension of the analytical potential expression of a three-plane parallel-electrode system to arbitrary apertures

Potential distributions in the entire space of a two-dimensional lens consisting of three parallel plates of symmetrical construction and arbitrary apertures are obtained analytically by finding special transformation functions between the real lens space and the corresponding imaginary one. The functions contain two arbitrary constants given as a function of the inner aperture, the outer aperture, and the half-lens space. The potential distribution on the optical axis exactly coincides with the one given analytically by G.D. Archard (Brit. J. Appl. Phys., vol.5, p.395, 1954). >

Analytic potential expression of a three-plane parallel-electrode system with special apertures

Potential distributions in all the space of a two-dimensional lens consisting of three parallel plates of symmetrical construction and specific apertures are obtained analytically by finding special transformation functions between the real lens space and the corresponding imaginary one. The functions contain two arbitrary constants m and n connecting the inner aperture 2Y i , the outer one 2Y o , and the distance d between the electrodes. The distance d is given by n\pi/2. Y_{in} = Y_{i}/d and Y_{on} = Y_{o}/d are functions of the ratio m/n only. Therefore, the transformation functions can be applied to specific combinations of Y in , Y on , and d . Y in = Y on = 0.6789884 is obtained for m/n = 0.1851789. As an example, a full mapping of the lines of potential and electric field for m = 1/4, n = 2 , and d = \pi is shown. In this case one obtains Y in = 0.6406773 and Y on = 0.5507097.

Pinch Phenomena in a Flash X-ray Discharge

The discharges were performed in a coaxial flash x-ray tube (voltage = 15 kv, pressure = 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-5</sup> to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> mm Hg and inductance = 75 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-9</sup> h) provided with a plane parallel electrode system. The discharge process has been studied by oscillographic recordings of any pair of the three quantities: current, its time derivative and x-ray output, inside the time interval during which the heavy current pulse (peak current about 25 ka) occurs in the discharge. The production of both single and multiple x-ray outputs of short duration (0.1 μsec or less) is discussed and seems to be caused by pinch phenomena occurring in a plasma column between the tube electrodes. Small changes in dI/dt during the pinching are interpreted as sausage instabilities which cause high local rates of increase in inductance giving a potential drop (V = I dL/dt) across each constriction of the discharge. Estimation of the accelerating voltage during the pinching showed that it could reach values almost four times as high as the applied initial capacitor voltage. In order to get the timing of the x-ray outputs under better control, a new method for discharge initiation is suggested.