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| 2. |
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| 3. |
- Wannberg, Björn, et al.
(författare)
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Angular distribution of photoelectrons from p levels in Ar, Kr and Xe close to threshold
- 1986
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 19:15, s. 2267-2277
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Tidskriftsartikel (refereegranskat)abstract
- Using a DC discharge VUV source equipped with a rotating, focusing reflection polariser in conjunction with a hemispherical electron spectrometer, the angular distribution of photoelectrons from the outermost p levels in the noble gases Ar, Kr and Xe was measured in the kinetic-energy region 0-3 eV. Discharges in Ne, Ar, Kr, Xe and N2 are used to obtain photons with energies in the range 11-19 eV. For photon energies between the ionisation thresholds for the P3/2 and P1/2 levels, observed rapid oscillations in beta are correlated with resonances with autoionising states. For higher photon energies, the energy dependence of beta is smooth.
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| 4. |
- Fink, Reinhold, et al.
(författare)
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Specific production of very long-lived core-excited sulfur atoms by 2p(-1)sigma* excitation of the OCS molecule followed by ultrafast dissociation
- 2006
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Ingår i: Journal of Physics B. - 0953-4075 .- 1361-6455. ; 39:12, s. L269-L275
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Tidskriftsartikel (refereegranskat)abstract
- A core-excited sulfur state with a lifetime almost one order of magnitude longer than in molecular 2p core-hole states is selectively produced by ultrafast dissociation of S 2p -> sigma* excited OCS. Clear evidence for this is provided by strong atomic peaks (20% of the total intensity) in x-ray fluorescence but very weak ones (2%) in the corresponding resonant Auger spectrum. Corroborating the assignment of the spectra, ab initio calculations explain the enhanced lifetime: the Auger decay of the produced D-3(3) (2p(5)3p(5)) sulfur state is strongly decreased as it contradicts a newly derived propensity rule of the L2,3MM Auger decay.
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| 5. |
- Hartman, Henrik, et al.
(författare)
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The FERRUM project: an extremely long radiative lifetime in Ti II measured in an ion storage ring
- 2003
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 36, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- We have extended the laser probing technique at the CRYRING storage ring to measurement of the extremely long lifetime (28 s) of the metastable 3d2(3P)4s b 4P5/2 level in Ti II. The result obtained demonstrates the power of this method for investigation of such long-lived levels. This is the first experimental lifetime investigation of metastable states in Ti II.
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| 6. |
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| 7. |
- Grumer, Jon, et al.
(författare)
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Hyperfine induced intensity redistribution in In II
- 2010
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 43:7
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Tidskriftsartikel (refereegranskat)abstract
- We present a theoretical investigation of the hyperfine structure of the 5s5d D-3(2)-5s4f F-3(2,3)0 transitions in In II. Earlier work has failed in determining hyperfine constants for the upper levels of these transitions. We show that this is due to strong off-diagonal hyperfine interaction, which not only changes the position of the individual hyperfine lines but also introduces large intensity redistributions among the different hyperfine levels. We present hyperfine dependent gf-values and show that off-diagonal hyperfine interaction reduces some of the gf-values by two orders of magnitude, while others are increased by up to more than a factor of 6. We also discuss the influence on the hyperfine structure of an accurate representation of the level-splitting of the 5s4f configuration. We show that the hyperfine interaction in F-3(3)0 and F-1(3)0 is very hard to determine accurately even in a large-scale calculation, and we derive a semi-empirical method for adjusting our results using an experimentally known, diagonal hyperfine constant for 5s4f F-1(3)0. The resulting theoretical synthetic spectra reproduce the experimental values to high accuracy and facilitate the identification of all observed lines.
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| 8. |
- Öhrwall, Gunnar, et al.
(författare)
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Photofragmentation of cyanogen upon carbon and nitrogen K-shell excitation by partial ion yield experiments
- 2010
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 43:9, s. 095201-
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Tidskriftsartikel (refereegranskat)abstract
- Partial ion yield spectroscopy was used to study fragmentation processes in cyanogen after C 1s and N 1s photoexcitation. The interpretation of the core excitation spectrum mostly follows the literature, but the high resolution has in some cases allowed a more detailed assignment. Using the fact that in Rydberg states there is an intensity increase as the fragmentation process becomes more extensive compared to valence orbitals, we have been able to distinguish resonances with valence and Rydberg character. Furthermore, we have been able to assign features in the ionization continuum as arising from double excitations or shape resonances, by observation of the suppression of anion yield at shape resonances.
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| 9. |
- Lynga, C, et al.
(författare)
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High-order harmonic generation in molecular gases
- 1996
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 29:14, s. 3293-3302
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Tidskriftsartikel (refereegranskat)abstract
- We present an experimental study of harmonic generation in molecular gases, using the fundamental (800 nm) and the second harmonic (400 nm) of a 150 fs titanium - sapphire laser at an intensity of ##IMG## [http://ej.iop.org/images/0953-4075/29/14/032/img1.gif] . We compare the conversion efficiency and the maximum energy obtained in different species: rare gases (Ar, Xe), diatomic molecules ( ##IMG## [http://ej.iop.org/images/0953-4075/29/14/032/img2.gif] , ##IMG## [http://ej.iop.org/images/0953-4075/29/14/032/img3.gif] , ##IMG## [http://ej.iop.org/images/0953-4075/29/14/032/img4.gif] , CO) and polyatomic molecules ( ##IMG## [http://ej.iop.org/images/0953-4075/29/14/032/img5.gif] , ##IMG## [http://ej.iop.org/images/0953-4075/29/14/032/img2.gif] O, ##IMG## [http://ej.iop.org/images/0953-4075/29/14/032/img7.gif] , ##IMG## [http://ej.iop.org/images/0953-4075/29/14/032/img8.gif] , ##IMG## [http://ej.iop.org/images/0953-4075/29/14/032/img9.gif] ). The harmonic spectra from molecular gases are very similar to those obtained in the atomic gases, with a plateau and a cutoff whose location is strongly correlated to the value of the ionization potential. The conversion efficiency is not higher than that of the rare gases.
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| 10. |
- Adenier, Guillaume, et al.
(författare)
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Is the fair sampling assumption supported by EPR experiments?
- 2007
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Ingår i: Journal of Physics B: At. Mol. Opt. Phys.. - : Institute of Physics ( IOP ), Bristol. - 0953-4075 .- 1361-6455. ; 40:1, s. 131-141
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Tidskriftsartikel (refereegranskat)abstract
- We analyse optical EPR experimental data performed by Weihs et al in Innsbruck 1997–1998. We show that for some linear combinations of the raw coincidence rates, the experimental results display some anomalous behaviour that a more general source state (like non-maximally entangled state) cannot straightforwardly account for. We attempt to explain these anomalies by taking account of the relative efficiencies of the four channels. For this purpose, we use the fair sampling assumption, and assume explicitly that the detection efficiencies for the pairs of entangled photons can be written as a product of the two corresponding detection efficiencies for the single photons. We show that this explicit use of fair sampling cannot be maintained to be a reasonable assumption as it leads to an apparent violation of the no-signalling principle.
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