1. |
- Bengtsson, G. J, et al.
(author)
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Natural Lifetimes of Excited-states of Neutral Nitrogen Determined By Time-resolved Laser Spectroscopy
- 1992
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In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 45:5, s. 2712-2715
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Journal article (peer-reviewed)abstract
- Radiative lifetimes were determined for three quartet states of neutral nitrogen, and sequences of Rydberg states were studied using depletion spectroscopy. Free nitrogen atoms were generated by photodissociation of N2O using frequency-tripled dye-laser radiation that was two-photon resonant with the 2p(2)3p 4S or 4D states. Further quartet states were reached by a subsequent single-photon absorption. We obtain tau(2p(2)3p 4D7/2) = 44(2) ns, tau(2p(2)3p 4S3/2) = 26.0(1.5) ns, and tau(2p(2)6s4P5/2) = 41(7) ns.
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2. |
- Carlsson, J, et al.
(author)
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Large Multiconfigurational Hartree-fock Calculations On the Hyperfine-structure Constants of the Li-7 2s 2s and 2p 2p States
- 1992
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In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 46:5, s. 2420-2425
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Journal article (peer-reviewed)abstract
- Accurate hyperfine-structure parameters for the ground and first excited states of lithium are reported. Hyperfine parameters are calculated from multiconfiguration Hartree-Fock (MCHF) wave functions using a recently written hyperfine-structure program, being a part of the MCHF Atomic Structure Package. Convergence of the hyperfine-structure parameters is studied as the active set of orbitals is increased. The relativistic, finite-nuclear-size, and finite-nuclear-mass-corrected values of the magnetic hyperfine-structure constants of the 2s S-2(1/2) and 2p P-2(1/2,3/2) states of Li-7 were determined to be A1/2=401.70 MHz and A1/2=45.94 MHz, A3/2=3.098 MHz, respectively. The final values are compared with experiments and with the most reliable theoretical values obtained with other methods.
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3. |
- Söderberg, Bo
(author)
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Apollonian tiling, the Lorentz group, and regular trees
- 1992
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In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 46:4, s. 1859-1866
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Journal article (peer-reviewed)abstract
- The Apollonian tiling of the plane into circles is analyzed with respect to its group properties. The relevant group, which is noncompact and discrete, is found to be identical to the symmetry group of a particular geometric tree graph in hyperbolic three-space. A linear recursive method to compute the radii is obtained. Certain modifications of the problem are investigated, and relations to other problems, such as the universal scaling of circle maps, are pointed out.
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