Complex angular momentum analysis of low-energy electron elastic scattering from lanthanide atoms

Journal Article · Thu Apr 15 00:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.042707· OSTI ID:21408623

Felfli, Z; Msezane, A Z ^[1]; Sokolovski, D ^[2]

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1. Department of Physics and Centre for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, Georgia 30314 (United States)
2. School of Mathematics and Physics, Queen's University of Belfast, Belfast, BT7 1NN (United Kingdom)

Electron attachment to the lanthanide and Hf atoms resulting in the formation of stable excited lanthanide and Hf anions as Regge resonances is explored in the near-threshold electron impact energy region, E<1.0 eV. The investigation uses the recent Regge-pole methodology wherein is embedded the electron-electron correlations together with a Thomas-Fermi-type model potential incorporating the crucial core-polarization interaction. The near-threshold electron elastic total cross sections (TCSs) for the lanthanide and Hf atoms are found to be characterized by extremely narrow resonances whose energy positions are identified with the binding energies (BEs) of the resultant anions formed during the collision as Regge resonances. The extracted BEs for excited lanthanide anions are contrasted with those of the most recently calculated electron affinities (ground state BEs). We conclude that the BEs for the Pr{sup -}, Tb{sup -}, Dy{sup -}, Ho{sup -}, Er{sup -}, and Tm{sup -} anions of O'Malley and Beck [Phys. Rev. A 79, 012511 (2009)] are not identifiable with the electron affinities as claimed. Formation of bound excited anions is identified in the elastic TCSs of all the lanthanide atoms including Hf, except Eu and Gd. The imaginary part of the complex angular momentum L, ImL is used to distinguish between the shape resonances and the bound excited negative ions. These results challenge both experimentalists and theoreticians alike since the excited anions are very weakly bound, but mostly tenuously bound (BEs<0.1 eV). Shape resonances and Ramsauer-Townsend minima are also presented.

• OSTI ID: 21408623
• Journal Information: Physical Review. A, Vol. 81, Issue 4; Other Information: DOI: 10.1103/PhysRevA.81.042707; (c) 2010 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
AFFINITY
ANGULAR MOMENTUM
ANIONS
ATOMS
BINDING ENERGY
COLLISIONS
ELASTIC SCATTERING
ELECTRON ATTACHMENT
ELECTRON CORRELATION
ELECTRONS
EV RANGE
GROUND STATES
RARE EARTHS
REGGE POLES
RESONANCE
THOMAS-FERMI MODEL
TOTAL CROSS SECTIONS
ATOMIC MODELS
CHARGED PARTICLES
CORRELATIONS
CROSS SECTIONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY
ENERGY LEVELS
ENERGY RANGE
FERMIONS
IONS
LEPTONS
MATHEMATICAL MODELS
METALS
SCATTERING