New measurements of the cross sections of doubly excited resonances in calcium
- 28 February 1988
- journal article
- Published by IOP Publishing in Journal of Physics B: Atomic, Molecular and Optical Physics
- Vol. 21 (4) , L83-L88
- https://doi.org/10.1088/0953-4075/21/4/003
Abstract
The authors report new cross section measurements, believed to be the first involving synchrotron radiation together with a 'hot-wire' diode detector, in which they have observed the doubly excited series of Ca I at a much improved signal to noise ratio using the radiation from the DORIS II electron accelerator and the HASYLAB facilities. The data provide new information on the 'vanishing width' effect in Ca I and are compared with several calculations of the cross section reported in recent literature. The best representation of the detailed structure appears to be achieved by the most recent combination of MQDT with the R-matrix method. All the calculations (R matrix and MBPT) underestimate the cross section in the 3d5p peak by 20-40%.Keywords
This publication has 17 references indexed in Scilit:
- Two-electron excitations in atomic calcium. IPhysical Review A, 1987
- The interaction between a Rydberg series and a shape or giant resonanceJournal of Physics B: Atomic and Molecular Physics, 1987
- Vanishing points of particle widths of resonances: an atomic parallel of a well known nuclear phenomenonJournal of Physics B: Atomic and Molecular Physics, 1985
- Rydberg structure within a broad resonanceJournal of Physics B: Atomic and Molecular Physics, 1985
- Autoionising line shapesJournal of Physics B: Atomic and Molecular Physics, 1985
- The double-electron resonances 3dnp1P1in the photoionisation spectrum of Ca IJournal of Physics B: Atomic and Molecular Physics, 1985
- Photoionization cross section of neutral calcium including double electron resonancesPhysical Review A, 1983
- On the coupling of a Rydberg series of discrete levels to a continuum of finite bandwidthProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1978
- Absorption spectrum of Ca i in the 1580–2090-Å regionJournal of the Optical Society of America, 1973
- Ultra-violet extensions of the arc spectra of the alkaline earths: the absorption spectrum of calcium vapourProceedings of the Physical Society, 1965