The investigation of electron-ion radiative and dielectronic recombination in high-temperature plasmas. Progress report for 1990--1991

Abstract

(1) The unified description of radiative and dielectronic recombination, which the authors have developed to provide corrections to the conventional independent-processes approximation, has been generalized to self-consistently incorporate the effects of charged-particle collisions and plasma electric fields. (2) The K{sub {alpha}} model for the dielectronic satellite spectra of highly-charged Fe ions, which the authors have developed based on the conventional theory of dielectronic satellite line intensities, has been incorporated into the multi-ion-species transport code MIST. Excellent agreement has been obtained between the simulated spectra and the observed Fe K{sub {alpha}} spectra from PLT and TFTR. (3) A detailed investigation has been completed on the dielectronic recombination satellite spectra in the presence of a distribution of plasma electric microfields. The calculations have been carried out for the lowest-lying n=2 satellites, which are affected by the electric fields only in high-density laser-produced plasma. For application to the lower-density conditions in tokamak plasmas, in which the electron density is about ten orders of magnitude smaller, a number of alternatives are under consideration for evaluating the recombination rates associated with the Rydberg autoionizing sates corresponding to large values of n. (3) A manuscript entitled ``Observation of Density-Enhanced Dielectronic Satellite Spectra Produced During Subpicosecond Laser-Matter Interactions`` has been submitted for publication in the Physical Review A. This work provides a convincing experimental verification of the theoretical predictions on the density sensitivity of diagnostically-important dielectronic satellite spectra in dense plasmas.