A Possibility of Detecting Fast Neutrons in a 10B Solid-gas Detector

The possibility of detecting thermal and fast neutrons in 10B solid-gas detector is considered. The simulation of the neutron detection process shows a significant difference in the detector signals caused by neutrons of different energies. An experimental verification of the detector’s operation was performed using W-Be photoneutron source with different ratio of fast and thermal neutrons incident on the detector. The measured amplitude spectra of the signals for different neutron energies were compared with the simulation results. The qualitative agreement between experimental and calculated data indicates the possibility of using this detector for recording thermal and fast neutrons

UV continuum emission and diagnostics of hydrogen-containing non-equilibrium plasmas

For the first time the emission of the radiative dissociation continuum of the hydrogen molecule ($a^{3}\Sigma_{g}^{+} \to b^{3}\Sigma_{u}^{+}$ electronic transition) is proposed to be used as a source of information for the spectroscopic diagnostics of non-equilibrium plasmas. The detailed analysis of excitation-deactivation kinetics, rate constants of various collisional and radiative transitions and fitting procedures made it possible to develop two new methods of diagnostics of: (1) the ground $X^{1}\Sigma_{g}^{+}$ state vibrational temperature $T_{\text{vib}}$ from the relative intensity distribution, and (2) the rate of electron impact dissociation (d[\mbox{H_{2}}]/dt)_{\text{diss}} from the absolute intensity of the continuum. A known method of determination of $T_{\text{vib}}$ from relative intensities of Fulcher-$\alpha$ bands was seriously corrected and simplified due to the revision of $d \to a$ transition probabilities and cross sections of $d \gets X$ electron impact excitation. General considerations are illustrated with examples of experiments in pure hydrogen capillary-arc and H$_{2}$+Ar microwave discharges.Comment: REVTeX, 25 pages + 12 figures + 9 tables. Phys. Rev. E, eprint replaced because of resubmission to journal after referee's 2nd repor

Ice imaging in aircraft anti-icing fluid films using polarized light

Article presents how to enhance ice contrast in the visible spectrum by using ice birefringence and polarized light reflection. The method can be used for both visual inspection and automatic ice detection systems

Optimal values of rovibronic energy levels for triplet electronic states of molecular deuterium

Optimal set of 1050 rovibronic energy levels for 35 triplet electronic states of $D_2$ has been obtained by means of a statistical analysis of all available wavenumbers of triplet-triplet rovibronic transitions studied in emission, absorption, laser and anticrossing spectroscopic experiments of various authors. We used a new method of the analysis (Lavrov, Ryazanov, JETP Letters, 2005), which does not need any \it a priory \rm assumptions concerning the molecular structure being based on only two fundamental principles: Rydberg-Ritz and maximum likelihood. The method provides the opportunity to obtain the RMS estimates for uncertainties of the experimental wavenumbers independent from those presented in original papers. 234 from 3822 published wavenumber values were found to be spurious, while the remaining set of the data may be divided into 20 subsets (samples) of uniformly precise data having close to normal distributions of random errors within the samples. New experimental wavenumber values of 125 questionable lines were obtained in the present work. Optimal values of the rovibronic levels were obtained from the experimental data set consisting of 3713 wavenumber values (3588 old and 125 new). The unknown shift between levels of ortho- and para- deuterium was found by least squares analysis of the $a^3\Sigma_g^+$, $v = 0$, $N = 0 \div 18$ rovibronic levels with odd and even values of $N$. All the energy levels were obtained relative to the lowest vibro-rotational level ($v = 0$, $N = 0$) of the $a^3\Sigma_g^+$ electronic state, and presented in tabular form together with the standard deviations of the empirical determination. New energy level values differ significantly from those available in literature.Comment: 46 pages, 9 picture

Label-free characterization of white blood cells using fluorescence lifetime imaging and flow-cytometry: molecular heterogeneity and erythrophagocytosis [Invited]

Article reporting the results of blood cell characterization using label-free fluorescence imaging techniques and flow-cytometry. Autofluorescence parameters of different cell types – white blood cells, red blood cells, erythrophagocytic cells – are assessed and analyzed in terms of molecular heterogeneity and possibilities of differentiation between different cell types in vitro and in vivo

Strong coupling between surface plasmon polaritons and Sulforhodamine 101 dye

We demonstrate a strong coupling between surface plasmon polaritons and Sulforhodamine 101 dye molecules. Dispersion curves for surface plasmon polaritons on samples with a thin layer of silver covered with Sulforhodamine 101 molecules embedded in SU-8 polymer are obtained experimentally by reflectometry measurements and compared to the dispersion of samples without molecules. Clear Rabi splittings, with energies up to 360 and 190 meV, are observed at the positions of the dye absorption maxima. The split energies are dependent on the number of Sulforhodamine 101 molecules involved in the coupling process. Transfer matrix and coupled oscillator methods are used to model the studied multilayer structures with a great agreement with the experiments. Detection of the scattered radiation after the propagation provides another way to obtain the dispersion relation of the surface plasmon polaritons and, thus, provides insight into dynamics of the surface plasmon polariton/dye interaction, beyond the refrectometry measurements

On determination of electronic-vibro-rotational term values of diatomic molecules from measured wavenumbers

A method is proposed for determining rovibronic term values of diatomics from experimental data on the wavenumbers of electronic-vibro-rotational spectral lines. In contrast to existing techniques, the new one is based on the Rydberg-Ritz principle only. It is shown that a link between a set of rovibronic term values and a set of wavenumbers of observed rovibronic spectral lines appears when three and more different electronic-vibrational states are pairwise-connected by radiative transitions. The method differs from known techniques in several aspects, namely, it: 1) doesn't need any assumptions concerning an internal structure of a molecule; 2) doesn't involve any intermediate parameters (as molecular constants in traditional techniques); 3) gives an opportunity to use in one-stage optimization procedure all available experimental data obtained for various band systems, by various authors, and in various works; 4) provides in an interactive mode the opportunity to select the experimental values, eliminating rough errors, to revise wrong identifications of spectral lines and to compare various sets of experimental data for mutual consistency; 5) allows to obtain not only an optimal set of rovibronic term values, but also the error bars depending on quantity and quality of existing experimental data. Necessary precondition for use of this method is a preliminary identification of electronic-vibro-rotational lines to certain electronic-vibro-rotational radiative transitions. For this purpose one has to use traditional methods of the analysis of molecular spectra.Comment: 10 pages, 2 figures, in Russia