Transient Development of Excited State Densities in Atomic Helium Plasmas

Abstract : The set of detailed rate equations describing the transient decay of singly ionized, constant temperature, constant pressure, monatomic helium plasmas is solved numerically for early times in the plasma decay. These equations, called the eigenstate rate equations, (ERE), have been studied previously for late times in the decay through application of the quasi-steady- state (QSS) assumption and have resulted in the collisional-radiative recombination (CRR) model for description of the electron density decay rate in plasmas. The application of the QSS to the ERE makes it impossible to study the mechanisms and the transient coupling by which the final distributions are estabilshed. The QSS Assumption is specifically removed in this study so that the ERE can be solved completely for the early transient characteristics of the plasma decay.