| 1. |
- Cacciani, P., et al.
(författare)
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Lifetime measurements of the e1II, v = 0 and v = 1 states of12C16O, 13C16O, and13C18O
- 1998
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Ingår i: Astrophysical Journal. - 0004-637X. ; 499:2 PART II, s. 223-226
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Tidskriftsartikel (refereegranskat)abstract
- In a laboratory investigation using tunable picosecond lasers in a pump-probe configuration, lifetimes of the E 1u, v = 0 and v = 1 states of CO are experimentally determined. For E 'D, v = 1, the lifetime is found to vary significantly for the isotopomers. Combining the data with existing oscillator strengths, predissociation probabilities within the range of 93.6%-98.6% result for 12C16O, 13C16O, and 13C18O in the case of the E 1u, v = I state, which is the state that predominantly influences the isotopic fractionation of CO in interstellar clouds.
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| 2. |
- Gratz, M, et al.
(författare)
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Time-gated x-ray tomography
- 1998
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 73:20, s. 2899-2901
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Tidskriftsartikel (refereegranskat)abstract
- Time-gated x-ray tomography with scatter reduction is demonstrated using a laser-produced plasma as an ultrashort-pulse x-ray source in combination with a time-resolving streak-camera detector. Backprojections of a phantom imbedded in 9 cm of water show an effective 50% increase in contrast when scattered x-ray quanta (being delayed in time) are suppressed by gating on the prompt, nonscattered photons. Implications for future volumetric tomography, in particular concerning possible dose reductions, are discussed. (C) 1998 American Institute of Physics. [S0003-6951(98)02846-0].
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| 3. |
- Larsson, J., et al.
(författare)
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Two-colour time-resolved spectroscopy of helium using high-order harmonics
- 1995
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 28:3, s. 53-58
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Tidskriftsartikel (refereegranskat)abstract
- The radiative lifetime of the ls2p1P state of helium is measured in a two-colour ionization experiment with a 5% accuracy. The state is excited by the 13th harmonic of a tunable SO ps laser and ionized by a synchronous ultraviolet laser, with a variable time delay. This experiment demonstrates that the high harmonics generated in a jet of rare gas exposed to an intense laser field provide a tunable short-pulse xuv source ideally suited for pump/probe type of studies and, in particular, short lifetime measurements.
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