Low-Energy Electron Elastic Collisions with Actinide Atoms Am, Cm, Bk, Es, No and Lr: Negative-Ion Formation

Journal Article · Tue Oct 19 00:00:00 EDT 2021 · Atoms

DOI:https://doi.org/10.3390/atoms9040084· OSTI ID:1826644

Msezane, Alfred Z.; Felfli, Zineb

The rigorous Regge-pole method is used to investigate negative-ion formation in actinide atoms through electron elastic total cross sections (TCSs) calculation. The TCSs are found to be characterized generally by negative-ion formations, shape resonances and Ramsauer-Townsend(R-T) minima, and they exhibit both atomic and fullerene molecular behavior near the threshold. Additionally, a polarization-induced metastable cross section with a deep R-T minimum is identified near the threshold in the Am, Cm and Bk TCSs, which flips over to a shape resonance appearing very close to the threshold in the TCSs for Es, No and Lr. We attribute these new manifestations to size effects and orbital collapse significantly impacting the polarization interaction. From the TCSs unambiguous and reliable ground, metastable and excited states negative-ion binding energies (BEs) for Am−, Cm−, Bk−, Es−, No− and Lr− anions formed during the collisions are extracted and compared with existing electron affinities (EAs) of the atoms. The novelty of the Regge-pole approach is in the extraction of the negative-ion BEs from the TCSs. We conclude that the existing theoretical EAs of the actinide atoms and the recently measured EA of Th correspond to excited anionic BEs.

• Sponsoring Organization: USDOE
• Grant/Contract Number: FG02-97ER14743
• OSTI ID: 1826644
• Journal Information: Atoms, Journal Name: Atoms Journal Issue: 4 Vol. 9; ISSN 2218-2004; ISSN ATOMC5
• Publisher: MDPI AG
• Country of Publication: Switzerland
• Language: English