[en] The electron transport in amorphous hydrogenated carbon-silicon diamond-like nanocomposite films containing tungsten over the concentration range 12-40 at.% was studied in the temperature range 80-400 K. The films were deposited onto polycrystalline substrates, placed on the RF-biased substrate holder, by the combination of two methods: PECVD of siloxane vapours in the stimulated dc discharge and dc magnetron sputtering of tungsten target. The experimental dependences of the conductivity on the temperature are well fitted by the power-law dependences over the entire temperature range. The results obtained are discussed in terms of the model of inelastic tunnelling of the electrons in amorphous dielectrics. The average number of localized states (n) in the conducting channels between metal clusters calculated in the framework of this model is characterized by the non-monotonic dependence on the tungsten concentration in the films. The qualitative explanation of the results on the basis of host carbon-silicon matrix structural modifications is proposed. The evolution of the carbon-silicon matrix microstructure by the increase in the tungsten concentration is confirmed by the Raman spectroscopy data

[en] Numerical analyses with the one-dimensional approximation have been carried out for a small-scale experimental device of TWDEC. The following results have been obtained. Numerical results agree well with experimental results on the conversion efficiency and the energy distribution when the phase difference between voltages of the modulator and the decelerator is the same as the experiment. It has been found that the phase difference should be determined properly in order to obtain a high efficiency. The position of electrodes in the decelerator has been optimized to obtain higher efficiency. The optimization is carried out for ions to move with the travelling electric field. It has been shown that the optimization can make the efficiency more than 58% when the number of electrodes is 16 even with the present small device

[en] The next generation of compact tandem-type DD or DT neutron generators requires a robust electron stripper with high charge exchange efficiency. In this study, stripping foils of various types were tested, and the H^- to H⁺ conversion efficiency, endurance to the heat load, and durability were investigated in terms of suitability in the tandem-type neutron generator. In the experiments, a H^- beam was accelerated to about 180 keV, passes through a stripping foil, and produces a mixed beam of H^-, H⁰, and H⁺. These ions were separated by an electric field, and detected by a movable Faraday cup to determine the conversion efficiency. The experimental results using thin foils of diamond-like carbon, gold, and carbon nano-tubes revealed issues on the robustness. As a new concept, a H^- beam was injected onto a metal surface with an oblique angle, and reflected H⁺ ions are detected. It was found that the conversion efficiency, H⁺ fraction in the reflected particles, depends on the surface condition, with the maximum value of about 90%.