56 research outputs found
YAG:Ce3+ nanostructured particles obtained via spray pyrolysis of polymeric precursor solution
Cerium-doped yttrium aluminum garnet (YAG:Ce3+) powder phosphor is synthesized via spray pyrolysis of polymeric precursor solution obtained by dissolving the corresponding nitrates in ethylenediaminetetraacetic acid (EDTA). Ultrasonically generated aerosol droplets are decomposed at 600 degrees C in argon atmosphere. Following the initial attempt in providing pure YAG:Ce3+, phase generation the particles were additionally thermally treated for 3 h in air at 1000 and 1100 degrees C. The powder morphology is followed with scanning electron microscopy (SEM), while inner particle structure is analysed by analytical and high-resolution transmission electron microscopy (TEM). Phase identification is performed by X-ray powder diffraction (XRPD) based on which a structural refinement through Rietveld method was done. The spherical submicronic particles have grained sub-structure comprising clustered garnet monocrystals sized below 100 nm. The YAG:Ce3+ emission shows wide peak in the range 470-600 nm with the maximum near 520 nm. (C) 2009 Elsevier Ltd. All rights reserved.11th Electroceramics Conference 2008, Sep 01-03, 2008, Univ Manchester, Manchester, Englan
Tests of proton laser-acceleration using circular laser polarization, foams and half gas-bag targets
We have analyzed laser-accelerated protons, generated at the rear surface of a solid target irradiated by an ultra-intense (I similar to 10(18) to 5 x 10(19) W cm(-2)) short laser pulse in different conditions: (1) using linear and circular polarization; (2) using 'foam' targets, i.e. targets where a density gradient has been artificially generated by adding a foam onto a solid and (3) using 'half gas-bag' targets, where the density gradient has been artificially generated by having a gas assembly in front of the solid. In all these varied conditions, and for our laser and target parameters, no enhancement of proton acceleration could be found, compared with the standard set-up using a linearly polarized laser irradiating a flat metal foil. Potential issues and solutions are discussed.</p
Tests of proton laser-acceleration using circular laser polarization, foams and half gas-bag targets
We have analyzed laser-accelerated protons, generated at the rear surface of a solid target irradiated by an ultra-intense (I similar to 10(18) to 5 x 10(19) W cm(-2)) short laser pulse in different conditions: (1) using linear and circular polarization; (2) using 'foam' targets, i.e. targets where a density gradient has been artificially generated by adding a foam onto a solid and (3) using 'half gas-bag' targets, where the density gradient has been artificially generated by having a gas assembly in front of the solid. In all these varied conditions, and for our laser and target parameters, no enhancement of proton acceleration could be found, compared with the standard set-up using a linearly polarized laser irradiating a flat metal foil. Potential issues and solutions are discussed.</p
K-edge Absorption spectra in Warm Dense Matter
International audienceno abstrac
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