Dielectronic recombination data for dynamic finite-density plasmas

Abstract

Dielectronic recombination (DR) rate coefficients for 22 sodium-like ions, between Mg+ and Xe 43+ , forming magnesium-like ions have been calculated as part of the assembly of a level-resolved DR database necessary for modelling dynamic finite-density plasmas, within the generalized collisional-radiative framework. Calculations have been performed from both ground and metastable initial states, in both LS -and intermediate coupling, allowing for ∆n = 0 and ∆n = 1 core-excitations from ground and metastable levels. Partial and total DR coefficients have been calculated for Mg + to Zn 19+ , as well as Kr 25+ , Mo 31+ , and Xe 43+ . Results for a selection of ions from the sequence are discussed in the paper and compared with existing theoretical and experimental results. A full set of results can be accessed from the Atomic Data and Analysis Structure (ADAS) database or from the Oak Ridge Controlled Fusion Atomic Data Center (http://www-cfadc.phy.ornl.gov/data_and_codes).

Optical Thomson scatter from a laser-ablated magnesium plume

“…However, experimental measurement of the DR cross section, made by crossing beams of electrons and singly ionized magnesium, Mg + ͑Refs. 35 and 36͒ suggests a cross section that is consistent with recent calculations of Altun et al 37 Using the fits of Altun et al we obtain a DR rate of 4 ϫ 10 −11 cm 3 s −1 for T = 1.5 eV. This means that at N e =10 17 cm −3 , we should have a typical recombination time of order 250 ns.…”

Experimental dielectronic recombination rate coefficients for Na-like S VI and Na-like Ar VIII

“…S vi plasma rate coefficents by Badnell (1991) and Altun et al (2006) have similar values and are ∼40% lower than our data, while above 6 × 10 4 K, the rate coefficients by Jacobs et al (1979) are ∼60% lower than our data. Below 1.3 × 10 4 K and 2 × 10 4 K the S vi and Ar viii plasma DR rate coefficients respectively contain mostly DR channels located below the field-ionization limits and are not affected by the procedure used to account for the field-ionization in the measurement.…”

Dielectronic recombination into Mg-like ions

“…Configuration mixing for 2p 6 [16], and Fournier et al [17] (Mg-like Mo) except for low temperature region. The behavior of the DR rate coefficients at low temperature strongly depends on the energy level structure.…”