Near-threshold infrared photodetachment of Al{sup {minus}}: A determination of the electron affinity of aluminum and the range of validity of the Wigner law
- Department of Physics, University of Nevada, Reno, Reno, Nevada 89557-0058 (United States)
- Department of Physics, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Las Vegas, Nevada 89154-4002 (United States)
The relative photodetachment cross section of Al{sup {minus}} has been measured in the wavelength range 2420{endash}2820 nm (0.440{endash}0.512 eV), using a coaxial ion-laser beams apparatus, in which a 2.98-keV Al{sup {minus}} beam is merged with a beam from an {ital F}-center laser. The cross-section data near the {sup 3}{ital P}{sub 0,1,2}{r_arrow}{sup 2}{ital P}{sub 1/2,3/2} photodetachment threshold have been fitted to the Wigner threshold law and to the zero-core-contribution theory of photodetachment. The electron affinity of aluminum was determined to be 0.44094(+0.00066/{minus}0.00048) eV, after correcting the experimental threshold for unresolved fine structure in the ground states of Al{sup {minus}} and Al. The new measurement is in agreement with the best previous measurement (0.441{plus_minus}0.010 eV) and is 20 times more precise. The Wigner law agrees with experiment within a few percent for photon energies within 3{percent} of threshold. A proposed leading correction to the Wigner law is discussed. {copyright} {ital 1996 The American Physical Society.}
- DOE Contract Number:
- FG02-91ER75667
- OSTI ID:
- 387539
- Journal Information:
- Physical Review A, Journal Name: Physical Review A Journal Issue: 4 Vol. 54; ISSN 1050-2947; ISSN PLRAAN
- Country of Publication:
- United States
- Language:
- English
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