29 research outputs found

    Vacuum-ultraviolet frequency-modulation spectroscopy

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    Frequency-modulation (FM) spectroscopy has been extended to the vacuum-ultraviolet (VUV) range of the electromagnetic spectrum. Coherent VUV laser radiation is produced by resonance-enhanced sum-frequency mixing (νVUV=2νUV+ν2\nu_{\mathrm{VUV}}=2\nu_{\mathrm{UV}}+\nu_2) in Kr and Xe using two near-Fourier-transform-limited laser pulses of frequencies νUV\nu_{\mathrm{UV}} and ν2\nu_2. Sidebands generated in the output of the second laser (ν2\nu_2) using an electro-optical modulator operating at the frequency νmod\nu_{\mathrm{mod}} are directly transfered to the VUV and used to record FM spectra. Demodulation is demonstrated both at νmod\nu_{\mathrm{mod}} and 2νmod2\nu_{\mathrm{mod}}. The main advantages of the method are that its sensitivity is not reduced by pulse-to-pulse fluctuations of the VUV laser intensity, compared to VUV absorption spectroscopy is its background-free nature, the fact that its implementation using table-top laser equipment is straightforward and that it can be used to record VUV absorption spectra of cold samples in skimmed supersonic beams simultaneously with laser-induced-fluorescence and photoionization spectra. To illustrate these advantages we present VUV FM spectra of Ar, Kr, and N2_2 in selected regions between 105000cm1^{-1} and 122000cm1^{-1}.Comment: 23 pages, 10 figure

    Harmonizing methods for wildlife abundance estimation and pathogen detection in Europe-a questionnaire survey on three selected host-pathogen combinations

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    __Background:__ The need for wildlife health surveillance as part of disease control in wildlife, domestic animals and humans on the global level is widely recognized. However, the objectives, methods and intensity of existing wildlife health surveillance programs vary greatly among European countries, resulting in a patchwork of data that are difficult to merge and compare. This survey aimed at evaluating the need and potential for data harmonization in wildlife health in Europe. The specific objective was to collect information on methods currently used to estimate host abundance and pathogen prevalence. Questionnaires were designed t

    37th International Symposium on Intensive Care and Emergency Medicine (part 3 of 3)

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