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This work presents an electric and kinetic study of homogeneous dielectric barrier discharge (DBD) in pure krypton (Kr). The electrical characterization and kinetic analyses of the DBD in Kr are performed. The plasma formation in DBD, excited by sinusoidal voltage at high pressure, was studied. The discharge development, with homogeneous model approach and using extended kinetic scheme, is simulated. The study is based on a spatial homogeneity model including the plasma chemistry, the electrical circuit and the Boltzmann equations'. The temporal variations of discharge voltage, dielectrics voltage, discharge current, electric field and species concentrations are calculated. The plasma kinetics is discussed with the aim to finding the optimal efficiency. The photon generation, under typical operating conditions, was investigated and discussed. The effect of some parameters on the excilamp like pressure, applied voltage, and frequency are investigated in order to identify the optimal parameters for maximum luminous efficiency in the UV range. [ABSTRACT FROM AUTHOR]

Both gold and rare-earth doped fluoride nanoparticles have been drawing interest for their possible biological applications, for therapy or for bioimaging. Gold nanoparticles can be used as a heat source for photothermal therapy, absorbing energy through its surface plasmon resonance (SPR) band and converting it to heat, whereas the low phonon energy, long emission lifetimes and sharp emission lines of the fluoride nanoparticles can circumvent several drawbacks of other used materials for bioimaging. In this context, this article proposes a modification of nanosized europium doped-LiYF4 with gold nanoparticles using a helium atmospheric plasma to reduce Au3+ to form the gold nanoparticles. In this article, we successfully synthesized citrate stabilized gold nanoparticles assisted by a helium atmospheric plasma, which showed a broad size distribution between 30 and 109 nm and different shapes, and a SPR band at 544 nm. We also successfully modified LiYF4:Eu3+ with gold nanoparticles with the atmospheric plasma jet, which presented a SPR band at 539 nm and significantly suppressed europium luminescence possibly due to the absorption of the emitted photons of the Eu3+ by the gold SPR band. [ABSTRACT FROM AUTHOR]