Fyzikální ústav Akademie věd ČR

Significant results of scientific activity in year 2014

We prepare InGaN/GaN multiple quantum well (MQW) structure by metal–organic vapor phase epitaxy (MOVPE) and characterize it by XRD, photoluminescence and radioluminescence measurements. We demonstrated its suitability for scintillator application by an unique measurement of wavelength-resolved scintillation response under nanosecond pulse soft x-ray source in extended dynamical and time scales. Further improvements of the structure are suggested, but even the...

Properties of the plasma plume produced on a Bi target irradiated by a focused extreme-ultraviolet capillary-discharge laser beam were investigated. Langmuir probes were used to determine the electron temperature and the electron density, providing values of 1–3 eV and ~1013–1014 m−3, respectively. Although the temperatures seem to be comparable with values obtained in ablation plasmas produced by conventional lasers, the density is significantly...

Mg-codoped Lu3Al5O12:Ce single crystal garnet scintillators were prepared with a wide concentration range 0–3000 ppm of Mg2+. Luminescence and scintillation characteristics were measured revealing the beneficial effect of Mg codoping which consists in stabilization of Ce4+ center. We propose a model explaining the mechanism of material improvement; the stable Ce4+ center provides an...

Currently, interest in biomedical applications of low temperature plasmas is rapidly growing. However, the understanding of the molecular mechanisms behind low temperature plasma cellular effects remains a significant challenge. In a recent study, we showed how different low temperature plasmas induce cell death via the formation of multiple intracellular reactive oxygen/nitrogen species. Our results suggest that the biological response to low temperature plasma treatment...

It is shown that spatial correlation functions measured for correlated photon pairs at the single-photon level correspond to speckle patterns visible at high intensities. This correspondence is observed for the first time in one experimental setup by using different acquisition modes of an intensified CCD camera in low and high intensity regimes. The behavior of intensity auto- and cross-correlation functions in dependence on pump beam parameters including power and...

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