1. Transport of energy by ultraintense laser-generated electrons in nail-wire targets.
- Author
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Ma, T., Key, M. H., Mason, R. J., Akli, K. U., Daskalova, R. L., Freeman, R. R., Green, J. S., Highbarger, K., Jaanimagi, P. A., King, J. A., Lancaster, K. L., Hatchett, S. P., Mackinnon, A. J., MacPhee, A. G., Norreys, P. A., Patel, P. K., Stephens, R. B., Theobald, W., Van Woerkom, L. D., and Wei, M. S.
- Subjects
LASER-plasma interactions ,ENERGY transfer ,RELATIVISTIC particles ,COPPER wire ,POLARIZED photons ,ULTRAVIOLET spectra ,SURFACE energy - Abstract
Nail-wire targets (20 μm diameter copper wires with 80 μm hemispherical head) were used to investigate energy transport by relativistic fast electrons generated in intense laser-plasma interactions. The targets were irradiated using the 300 J, 1 ps, and 2×10
20 W·cm-2 Vulcan laser at the Rutherford Appleton Laboratory. A spherically bent crystal imager, a highly ordered pyrolytic graphite spectrometer, and single photon counting charge-coupled device gave absolute Cu Kα measurements. Results show a concentration of energy deposition in the head and an approximately exponential fall-off along the wire with about 60 μm 1/e decay length due to resistive inhibition. The coupling efficiency to the wire was 3.3±1.7% with an average hot electron temperature of 620±125 keV. Extreme ultraviolet images (68 and 256 eV) indicate additional heating of a thin surface layer of the wire. Modeling using the hybrid E-PLAS code has been compared with the experimental data, showing evidence of resistive heating, magnetic trapping, and surface transport. [ABSTRACT FROM AUTHOR]- Published
- 2009
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