Comparison of Two Models for Breakdown Waves

In this paper, the two theories concerning the propagation of breakdown waves are compared. The two theories are as follows: 1. The photoionization theory, in which the driving force of the propagation is the electromagnetic radiation from the hot gas generated at the electrode with the greatest potential gradient. 2. The electron fluid dynamical theory, in which the driving force of the propagation is the partial pressure of the high temperature electron gas generated in the neighborhood of the pulsed electrode. Successes in explaining the experimental data will be compared

Proforce Waves: The Effect of Current Behind the Shock Front on Wave Structure

Recently, the initial boundary conditions for proforce waves with a substantial current behind the shock front have been derived. Computer solutions of the Electron Fluid Dynamical equations meet the expected boundary conditions at the end of the sheath region. This paper will compare the wave structure for proforce waves with and without current behind the shock front

Electric Discharge: Boundary Conditions

The electron gas in electric discharge can be described by a set of one-dimensional fluid dynamical equations. The fundamental equations are those of a three-component (electrons, ions, and neutral particles) fluid, different from the treatment of the problem inplasma physics, a fully ionized two-component case. The leading edge of the wave is treated as a shock front driven mainly by the electron gas pressure. Integrating the one-dimensional global differential equations for mass balance, conservation of momentum and energy, and evaluating the constant of integration at the wave front permits derivation of boundary conditions on electron temperature and electron velocity. Using the boundary conditions on electron temperature and electron velocity we have been able to calculate the initial boundary condition on energy terms due to the electron random and directed motions. Using the initial boundary conditions we have been able to integrate the set of electron fluid dynamical equations through the dynamical transition region of the wave. We will present the derivation of the boundary conditions as well as the wave profile for the electric field, electron velocity, electron temperature, electron number density, and ionization rate within the dynamical transition region of the wave for a fast moving wave

Wave Profile for Antiforce Class II Waves

Breakdown waves propagating in the opposite direction of the applied electric field force are referred to as antiforce waves. Breakdown waves moving into a pre-ionized medium are referred to as Class II waves. Using a one-dimensional, steady state, three-fluid, hydrodynamical model and considering the electrons as the main element in propagation of ionizing waves, we have derived the proper boundary conditions for antiforce waves moving into a preionized medium. Using the new boundary conditions and for several current values ahead of the wave, the set of electron fluid dynamical equations (equations of conservation of mass, momentum, and energy coupled with Poison\u27s equation) has been integrated through the dynamical transition region. The solutions meet the expected boundary conditions at the end of the wave. The electron velocity and electric field values conform to the physical conditions at the end of the dynamical transition region. For several current values ahead of the wave, the wave profile for electric field, electron velocity, electron temperature, and electron number density will be presented

Effects of Science Crusade in Arkansas

The NSF funded Arkansas Statewide Systemic Initiative (1992), developed with the intent to restructure mathematics and science education in Arkansas, is a recent reform in the Arkansas educational system. The project aimed at changing Arkansas students\u27 attitudes toward science and mathematics, improving student learning and performance, introducing appropriate technology into the classrooms, and allowing for a lasting community involvement in the Arkansas educational system. To implement change through Arkansas Science and Math Crusades, the project has provided large scale teacher training and professional development opportunities to Arkansas school teachers. This reform effort in education started in 1992. A search of the ERIC Database back to 1992 produces no relevant records relating to Crusades in general nor the Science Crusade in particular. This article presents the results of a study of the effects of the Science Crusade as viewed by Arkansas River Valley science teachers who have participated in the Science Crusade training

Wave Profile for Proforce Current Bearing Waves

A complete wave profile for proforce style of breakdown waves with a current behind the shock front is discussed. The solution of the electron fluid dynamical equations in the sheath region for proforce current bearing waves conforms with the expected conditins for the values of the dynamical variables at the trailing edge of the wave. The wave profile for electric field and electron velocity, temperature, and number density are presented

Electron Shock Waves: Effect of Current on Electron Temperature and Density

In our attempt to find analytical solutions for breakdown waves, we employ a set of three-component fluid equations. In addition to reporting the method of integration of electron fluid dynamical equations through the dynamical transition region (sheath region), the wave profile for ionization rate, electron number density and electron temperature inside the sheath will be discussed. Also, the effect of the current on electron temperature, electron number density and ionization rate will be reported

The exact solution of the electron-fluid dynamical equations.

Electrical breakdown is generally a progressive wave phenomenon governed by fluid dynamical equations relating mainly to the electron gas. Computer solution of these equations has now been investigated extensively, resulting in improvements in their formulation and in the understanding of the conditions under which solution is possible. In this work the advance of the proforce waves into both neutral and preionized gas has been investigated, and the results are completely satisfactory. Also in this work the advance of the antiforce waves, with and without current, has been investigated and we were able to meet the boundary conditions at the end of the wave within the accuracy of the integration step. The most significant new discovery is the importance of heat conduction and existence of an electron temperature derivative discontinuity at the leading edge of the wave