Self-consistent Electrostatic Field Research Articles

Structure of Wall Plasmas near Divertor Neutralizer Plates or Limiters

The structure of wall plasmas near neutralizer plates or limiters is calculated with a kinetic transport model which includes binary collision processes between the various ion, atomic, and molecular species, and the self-consistent electrostatic field. A family of solutions is found which may be used in calculating removal of heat and impurities.

A simple self-consistent electrostatic field approximation for neighbour strand interactions in band structure calculations

A self-consistent electrostatic field approximation in one-dimensional band structure calculations has been employed for a more realistic description of the environment in real solids. Band structure calculations of INDO type are presented for HCN, HF, HCl and polydiacetylene in a vacuum and in the field of neighbouring chains. Pronounced modifications of band energies and significant charge redistributions are predicted.

Realistic Vlasov slab equilibria with magnetic shear

A method is described for generating exact Vlasov slab equilibria to model high-beta plasmas with strong magnetic shear. Physically reasonable distribution functions that account for such effects as end losses and density gradients are constructed from constants of the motion and used to calculate the self-consistent electrostatic and magnetic fields. As an application, numerically calculated equilibria modeling a tormac sheath are presented.

The effect of space charge electric field on ion implantation in dielectrics

The space charge formation in a plane dielectric specimen irradiated by a monodirectional monoenergetic low-energy ion beam incident perpendicular to the surface of the specimen is investigated theoretically. The effect of the self-consistent electrostatic field of the space charge on ion transport and range distribution in dielectrics is treated. The analytical expression for the non-stationary depth and velocity distribution function of moving particles is obtained. The dependence of ion implantation depth upon radiation time taking into account the effect of the electrostatic field of the implanted ions on moving particles is calculated for the given law of ion interaction with the atoms of the material. The effect of a possible “leakage” of the space charge is analyzed.

The convergence and accuracy of the method of macroparticles

THE ACCURACY of the method of macroparticls for the Child-Langmuir problem is investigated. It is shown that the difference the self-consistent electrostatic field obtained from the discrete model and the self-consistent electrostatic field of the kinetic model is O(N 1 2 ) .

Calculation of electrostatic fields in ionic crystals based upon the Ewald method

Formulas for the electrostatic potential, field strength and field gradient due to monopoles, dipoles and quadrupoles are given, based upon the Ewald summation method. A convenient choice of the convergence parameter in the Ewald method is demonstrated in some actual calculations. A method to calculate self-consistent electrostatic fields due to self induced dipoles is evaluated. Monopole and self-consistent fields are calculated in Pb 2O 3, βMn 2 O 3, FeTiO 3, MnF 3 and Pb 3O 4. The influence of the anion parameter on the electrostatic field is investigated for idealized CdCl 2 and TiO 2. Results of Madelung and induced dipole polarization energy for a series of arbitrary compounds are given. The effect of spontaneous polarization in polar crystals is discussed.

Self-consistent electrostatic field mapping in the high-latitude ionosphere

In an attempt to study the possible connections between upper and lower atmospheric electricity, the restricted boundary value problem of self-consistent electrostatic field mapping in the collision-dominated lower ionosphere is solved. Although large scale size perpendicular fields can penetrate the ionosphere, the associated self-consistent parallel fields are much more sensitive to the parameters of the ionosphere and atmosphere. Above 150 km the parallel field is generally 10−3–10−4 times the magnitude of the perpendicular field; however, below 100 km the two fields become comparable in magnitude. It is found that the magnetospheric origin of perpendicular electric fields measured at low-altitude and high-latitude regions cannot be ascertained unless simultaneous subsidiary observations such as magnetic disturbances and perpendicular scale sizes are also considered.

The electronic quadrupole polarizibility of the oxygen ion in ionic solids

The calculation of self-consistent electrostatic fields and field gradients in corundum (α - Al 2O 3) shows that the electronic quadrupole polarizibility of the oxygen ion in this crystal structure must be smaller than 1×10 −40 cm 5. The most probable value is between 0.2 and 0.3×10 −40 cm 5. Although this value is relatively small the effect of the oxygen quadrupole moments on the potential distribution is considerable.