Microstructure theory for three dimensional plasma transport. Technical report

Microstructure theory is a stochastic approach to plasma simulation which accounts for structures unresolved by sampling. A stochastic approach to plasma simulation is called for by the need to address a large range of plasma structure scale sizes in the simulation of high-altitude nuclear environments. The microstructure approach to a 2-dimensional split-step numerical simulation of electrostatic plasma evolution is presented with comparison to the classical split-step approach. The primary difference between the two approaches rests in the assumed dependence of the plasma conductivity upon plasma density statistics. Justification for the microstructure conductivity assumption from numerical experiments is presented. Numerical simulations of barium-like plasma clouds and nuclear clouds under the influence of radial winds are presented which illustrate physically realistic results. Numerical considerations are also discussed. In extensions of microstructure theory from 2-dimensional plasma evolution to 3-dimensional transverse transport the nature of the correlation of plasma structure along magnetic field lines is a key consideration. For the case of complete correlation, i.e., correlation with a correlation coefficient of plus or minus 1, three-dimensional algorithms are developed and implemented in a version of SCENARIO. The algorithms are physically appealing in form, reflecting many of the expected attributes of gradient-drift phenomena. The resultsmore » of a Cheyenne Mt. calculation are given.« less