Emission lifetimes of a fluorescent dye under shock compression [electronic resource].
- Washington, D.C. : United States. National Nuclear Security Administration, 2015. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
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- pages 10,910-10,916 : digital, PDF file
- Additional Creators:
- United States. National Nuclear Security Administration and United States. Department of Energy. Office of Scientific and Technical Information
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- Free-to-read Unrestricted online access
- The emission lifetimes of rhodamine 6G (R6G), were measured under shock compression to 9.1 GPa, with the dual intent of better understanding molecular photophysics in extreme environments and assessing the usefulness of fluorescence lifetime microscopy to measure spatially-dependent pressure distributions in shocked microstructured media. R6G was studied as free dye dissolved in poly-methyl methacrylate (PMMA), or dye encapsulated in silica microparticles suspended in PMMA. Thin layers of these materials in impedance-matched geometries were subjected to planar single-stage shocks created by laser-driven flyer plates. A synchronized femtosecond laser excited the dye at selected times relative to flyer plate arrival and the emission lifetimes were measured with a streak camera. Lifetimes decreased when shocks arrived. The lifetime decrease was attributed to a shock-induced enhancement of R6G nonradiative relaxation. At least part of the relaxation involved shock-enhanced intersystem crossing. For free dye in PMMA, the lifetime decrease during the shock was shown to be a linear function of shock pressure from 0-9 GPa, with a slope of -0.22 ns·GPa<sup>-1</sup>. Furthermore, the linear relationship makes it simple to convert lifetimes into pressures. Lifetime measurements in shocked microenvironments may be better than emission intensity measurements, since lifetimes are sensitive to the surrounding environment, but insensitive to intensity variations associated with the motion and optical properties of a dynamically changing structure.
- Published through SciTech Connect., 10/15/2015., Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory 119 44 ISSN 1089-5639 AM, Wei-long Liu; Will P. Bassett; James M. Christensen; Dana D. Dlott., and Carnegie Institution of Washington, Washington, D.C. (United States)
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