Improving the dicenter model for hot dense plasmas: molecular stark effect

In previous work of the dicenter model, used to take into account the ionic correlation effects in hot dense plasmas, only considered a single perturb ing ion (i.e., the nearest neighbor ion) thus limiting its range of applica bility. The improvement proposed in the present work includes the effect of all perturbing ions through a quasistatic external microfield acting on a "quasi-molecule". This enlarges the domain of validity of the dicenter mode l. For low densities this new alternative model gives line widths in agreem ent with standard "monocenter" profiles without artificially reducing the e lectron screening inside the dicenter emitting cell. This reduced screening , which had been employed to treat the repulsive interactions between the q uasi-molecule and the other perturbing ions, is removed in the present work . (C) 2001 Elsevier Science Ltd. All rights reserved.