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Collision-induced desorption of CO from Ru(0001) by hyperthermal argon and nitrogen
No full textCollision-induced desorption of CO from Ru(0001) by hyperthermal (5–9 eV) effusive beams of Ar and N + N2 has been studied at a sample temperature of 400 K. Prompt desorption occurs with cross sections on the order of 4 Å2. Based on post-exposure thermal desorption measurements, 1/3 of the initial CO coverage cannot be desorbed by Ar on the time scale of the current experiments. In contrast, exposure to the mixed N + N2 beam appears to remove all CO from the irradiated region. This is attributed to a lowering of the CO binding energy by adsorbed N-atoms. While there is no evidence of a large influence of surface diffusion on the time scale of these exposure, desorption simulations suggest that local diffusion in the periphery of the exposed region influences the measured decay
Luminescent Metamaterials for Solid State Lighting
No full textWe investigate the luminescent spectrum of thin films of dye molecules embedded in a polymer layer and on top of an array of aluminum nanoparticles. The emission couples to quasi-guided modes that are efficiently coupled out to free space by scattering with the particle array. This outcoupling provides a significant enhancement of the emission in defined directions. The mode density changes and the spectrum is modified by varying the thickness of the layer. In consequence, the luminous efficacy of the layer of dye can be controlled by the layer thickness and the characteristics of the particle array. This system can be regarded as a luminescent metamaterial with designed properties that can be exploited in solid state lighting applications
Observation of a helium ion energy threshold for retention in tungsten exposed to hydrogen/helium mixture plasma
No full textHelium retention is measured in tungsten samples exposed to mixed H/He plasma in the Magnum-PSI linear plasma device. It is observed that there is very little He retention below helium ion impact energies of 9.0 +- 1.4 eV, indicating the existence of a potential barrier which must be overcome for implantation to occur. The helium retention in samples exposed to plasma at temperatures >1000 K is strongly correlated with nano-bubble formation measured using grazing incidence small-angle x-ray scattering. The diameters of nano-bubbles were not found to increase with increasing helium concentration, indicating that additional helium must be accommodated by increasing the bubble concentration or an increase in bubble pressure. For some samples pre-irradiation with heavy ions of 2.0 MeV energy is investigated to simulate the effects of neutron damage. It is observed that nano-bubble sizes are comparable between samples pre-irradiated with heavy-ions, and those without heavy-ion pre-irradiation
Optimizing the parameter space for increased crystallinity of silicon nanoparticles grown in the gas phase
No full textsee also: back cove
CO2-Neutral Fuels
No full textMimicking the biogeochemical cycle of System Earth, synthetic hydrocarbon fuels are produced from recycled CO2 and H2O powered by renewable energy. Recapturing CO2 after use closes the carbon cycle, rendering the fuel cycle CO2 neutral. Non-equilibrium molecular CO2 vibrations are key to high energy efficiency.</p
Erratum: In situ spectroscopic ellipsometry during atomic layer deposition of Pt, Ru and Pd (2016 J. Phys. D: Appl. Phys . 49 115504)
No full textFigure 6 was incorrectly edited in the above paper. The corrected figure is given.</p
Dual frequency diffuse dielectric barrier discharge in atmospheric-pressure air-like gas mixture for thin film deposition
No full textImage quality method as a possible way of in situ monitoring of in-vessel mirrors in a fusion reactor
No full textThe plasma-facing (first) mirrors in ITER will be subject to sputtering and/or contamination with
rates that will depend on the precise mirror locations. The resulting influence of both these factors
can reduce the mirror reflectance (R) and worsen the transmitted image quality (IQ). This implies that
monitoring the mirror quality in situ is an actual desire, and the present work is an attempt towards
a solution. The method we propose is able to elucidate the reason for degradation of the mirror
reflectance: sputtering by charge exchange atoms or deposition of contaminated layers. In case of
deposition of contaminants, the mirror can be cleaned in situ, but a rough mirror (due to sputtering)
cannot be used anymore and has to be replaced. To demonstrate the feasibility of the IQ method,
it was applied to mirror specimens coated with carbon film in laboratory conditions and to mirrors
coated with contaminants during exposure in fusion devices (TRIAM-1M and Tore Supra), as well as
to mirrors of different materials exposed to sputtering by plasma ions in the DSM-2 plasma stand (in
IPP NSC KIPT)
