Influence of Centrifugal Barrier Effects on the Autoionising Resonances

The lgo potential is used for the calculation of barrier penetrabilities for ground-state and excited-state transitions of even–even nuclei and for transitions of odd–odd nuclei, measured after 1959. The barrier penetration factors were calculated by numerical integration in the WKB approximation, taking into consideration centrifugal barrier effects for even–even nuclei, but ignoring non-central interactions. Using the calculated penetration factors and the experimental alpha half-lives, the reduced level widths were calculated in each case. The barrier penetration factors and the reduced level widths are given for total decay energy (alpha-particle energy plus electron-screening correction plus recoil energy).

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Near-threshold Behaviour of Generalised Oscillator Strengths for 2p Ionisation

Australian Journal of Physics ◽

10.1071/ph940271 ◽

1994 ◽

Vol 47 (3) ◽

pp. 271

Author(s):

R Padma ◽

PC Deshmukh

Keyword(s):

Electron Impact ◽

Atomic Oxygen ◽

Local Density ◽

Oscillator Strengths ◽

Threshold Behaviour ◽

Centrifugal Barrier ◽

Atomic Potential ◽

Barrier Effects ◽

Iron And Zinc ◽

Impact Ionisation

Near the ionisation threshold, the behaviour of the generalised oscillator strength (GOS) is sensitive to the choice of the model atomic potential. In electron-impact ionisation, 'delayed maxima' of the GOS often occur near the ionisation threshold due to centrifugal barrier effects. In the present work, the sensitivity of this important effect of the centrifugal barrier to the model atomic potential has been studied using two local density atomic potentials, namely, the nonrelativistic Hartree-Slater potential and the relativistic RCB potential. Calculations have been done for electron-impact 2p ionisation of atomic oxygen, neon, aluminium, argon, iron and zinc. The GOS results for 2p ionisation of oxygen and aluminium are presented to illustrate the results.

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Centrifugal barrier effects in the high Rydberg states and autoionising resonances of neon

Journal of Physics B Atomic and Molecular Physics ◽

10.1088/0022-3700/17/9/017 ◽

1984 ◽

Vol 17 (9) ◽

pp. 1785-1796 ◽

Cited By ~ 44

Author(s):

M A Baig ◽

J P Connerade

Keyword(s):

Rydberg States ◽

Centrifugal Barrier ◽

Barrier Effects

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Molecular damping of centrifugal barrier effects in the 3d absorption spectrum of selenium vapour

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1977.0125 ◽

1977 ◽

Vol 356 (1684) ◽

pp. 135-147 ◽

Cited By ~ 10

Keyword(s):

Absorption Spectrum ◽

Recent Work ◽

Absorption Spectra ◽

Conduction Band ◽

Density Of States ◽

Molecular Field ◽

Centrifugal Barrier ◽

Barrier Effects ◽

Diatomic Systems ◽

Shape Resonances

In the light of recent work on shape resonances in diatomic systems, the question of a possible persistence of atomic centrifugal barrier effects in molecules arises, particularly as regards resonant penetration of f-waves. Experiments on selenium vapour suggest that two cases may be expected depending on whether localized f states are present or not in the atom. The evidence in Se is that f waves mainly external to the atom are scattered into several channels by the anisotropic molecular field and that damping of the f-maximum results. A reason is suggested for which inner shell absorption spectra of solids may not faithfully reproduce the density of states of the conduction band, even for elemental materials.

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