### Abstract

A recent measurement of the dielectronic recombination (DR) of W20+ [Schippers et al., Phys. Rev. A 83, 012711 (2011)] found an exceptionally large contribution from near-threshold resonances (less than or similar to 1 eV). This still affected the Maxwellian rate coefficient at much higher temperatures. The experimental result was found to be higher by a factor of 4 or more than that currently in use in the 100- to 300-eV range, which is of relevance for modeling magnetic fusion plasmas. We have carried out DR calculations with AUTOSTRUCTURE which include all significant single-electron promotions. Our intermediate-coupling (IC) results are more than a factor of 4 larger than our LS-coupling ones at 1 eV but still lie a factor of 3 below experiment here. If we assume complete (chaotic) mixing of near-threshold autoionizing states, then our results come into agreement (to within 20%) with experiment below less than or similar to 2 eV. Our total IC Maxwellian rate coefficients are 50%-30% smaller than those based on experiment over 100-300 eV.

Language | English |
---|---|

Article number | 052716 |

Number of pages | 9 |

Journal | Physical Review A |

Volume | 85 |

Issue number | 5 |

DOIs | |

Publication status | Published - 29 May 2012 |

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### Keywords

- dielectronic recombination
- half open f shell
- modeling magnetic fusion plasmas

### Cite this

*Physical Review A*,

*85*(5), [052716]. https://doi.org/10.1103/PhysRevA.85.052716

}

*Physical Review A*, vol. 85, no. 5, 052716. https://doi.org/10.1103/PhysRevA.85.052716

**Dielectronic recombination of W20+ (4d(10)4 f(8)) : addressing the half-open f shell.** / Badnell, N. R.; Ballance, C. P.; Griffin, D. C.; O'Mullane, M.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Dielectronic recombination of W20+ (4d(10)4 f(8))

T2 - Physical Review A - Atomic, Molecular, and Optical Physics

AU - Badnell, N. R.

AU - Ballance, C. P.

AU - Griffin, D. C.

AU - O'Mullane, M.

PY - 2012/5/29

Y1 - 2012/5/29

N2 - A recent measurement of the dielectronic recombination (DR) of W20+ [Schippers et al., Phys. Rev. A 83, 012711 (2011)] found an exceptionally large contribution from near-threshold resonances (less than or similar to 1 eV). This still affected the Maxwellian rate coefficient at much higher temperatures. The experimental result was found to be higher by a factor of 4 or more than that currently in use in the 100- to 300-eV range, which is of relevance for modeling magnetic fusion plasmas. We have carried out DR calculations with AUTOSTRUCTURE which include all significant single-electron promotions. Our intermediate-coupling (IC) results are more than a factor of 4 larger than our LS-coupling ones at 1 eV but still lie a factor of 3 below experiment here. If we assume complete (chaotic) mixing of near-threshold autoionizing states, then our results come into agreement (to within 20%) with experiment below less than or similar to 2 eV. Our total IC Maxwellian rate coefficients are 50%-30% smaller than those based on experiment over 100-300 eV.

AB - A recent measurement of the dielectronic recombination (DR) of W20+ [Schippers et al., Phys. Rev. A 83, 012711 (2011)] found an exceptionally large contribution from near-threshold resonances (less than or similar to 1 eV). This still affected the Maxwellian rate coefficient at much higher temperatures. The experimental result was found to be higher by a factor of 4 or more than that currently in use in the 100- to 300-eV range, which is of relevance for modeling magnetic fusion plasmas. We have carried out DR calculations with AUTOSTRUCTURE which include all significant single-electron promotions. Our intermediate-coupling (IC) results are more than a factor of 4 larger than our LS-coupling ones at 1 eV but still lie a factor of 3 below experiment here. If we assume complete (chaotic) mixing of near-threshold autoionizing states, then our results come into agreement (to within 20%) with experiment below less than or similar to 2 eV. Our total IC Maxwellian rate coefficients are 50%-30% smaller than those based on experiment over 100-300 eV.

KW - dielectronic recombination

KW - half open f shell

KW - modeling magnetic fusion plasmas

U2 - 10.1103/PhysRevA.85.052716

DO - 10.1103/PhysRevA.85.052716

M3 - Article

VL - 85

JO - Physical Review A - Atomic, Molecular, and Optical Physics

JF - Physical Review A - Atomic, Molecular, and Optical Physics

SN - 1050-2947

IS - 5

M1 - 052716

ER -