A superconducting metallic film bolometer in contact with thermal bath of temperature T0, is biased by a (i) constant current $I_{\mathrm{b} }$, or by (ii) the constant voltage $U_{\mathrm{b}}$. The absorption of the time-dependent power of a phonon beam W(t) elevates temperature of the film to $T(t)>T_{\mathrm{0}}$. The thermal contact of the bolometer with the environment is characterized by the thermal conductance G, and it depends on $[T^{n}(t)-T_{\mathrm{0}}^{n}]$ ($n=4{-}6$). For both above methods of bias, we derive ordinary nonautonomous nonlinear differential equations of the first order. These equations are numerically solved. The knowledge of W(t) allows one to calculate (i) $U_{\mathrm{b} }(t)$ or (ii) $I_{\mathrm{b}}(t)$. The inverse problem of calculation of W(t) from known (i) $U_{\mathrm{b}}(t)$ or (ii) $I_{\mathrm{b}}(t)$ is also solved. Using W(t) calculated in computer experiments, we obtained the bolometer signal, and compared it with results of real experiments performed on GaAs in which $I_{\mathrm{b}}$ is fixed, and U is measured. Comparison of calculated results with results obtained for the linearized model shows that the nonlinearity is essential for the correct description of metallic superconducting film bolometer response.

A semi-analytical version of single-angle ellipsometric inversion to determine the refractive index of non-absorbing films is re-examined to explore the possibility of speeding up and enhancing the reliability of its computational implementation by an a priori rejection of one of two potential solutions propagated from the one of the two roots of the quadratic equation arisen in the inversion process. The distribution of solution-determining parameters and root selection over the (refractive index)-thickness solution space depending on the measurement variables of wavelength and angle of incidence is surveyed and exhibits an interesting pattern, which can be harnessed depending on materials. Optimization depending on the measurement variables and potential application in spectroscopic and in situ ellipsometry is discussed. The feasibility of the method has been tested with samples of aluminium oxide and titanium oxide films on silicon substrates.

ESR, IR, optical absorption and photoluminescence spectra of Ho3+ doped tungsten phosphate glasses modified with three different modifier oxides viz., PbO, ZnO and CaO have been studied. The ESR spectral studies indicate tungsten ions are present in W5+ state in all the three glasses with the highest concentration in CaO modified glasses. From the measured intensities of various absorption bands of these glasses, the Judd-Ofelt (JO) parameters $\Omega_2$, $\Omega_4$ and $\Omega_6$ have been evaluated. The JO theory could successfully be applied to characterise the absorption and luminescence spectra of these glasses. From this theory various radiative properties like radiative transition probabilities, A, branching ratios, $\beta_r$, the radiative lifetimes, $\tau_R$, and the emission cross-sections, σE, for various emission levels of Ho3+ in these glasses have been determined and reported. An attempt has also been made to throw some light on the environment of Ho3+ ions in all the three glasses.

A null collision Monte Carlo method is proposed to calculate the transport kinetics of charged particles in a non equilibrium background of atoms or molecules. The method is an implementation of the null collision Monte Carlo method of Skullerud, extended in order to include the translational distribution of neutrals, also in non uniform cases. As such, it delivers an exact solution of the linear Boltzmann equation. Two equivalent formulations of the method are proposed: an inductive one based on physical considerations, and a more formal one in which the method is deduced from the appropriate transport equation. As a test case, the method is applied to the thermal diffusion of H3+ ions diluted in H2 under an isobaric thermal gradient and with a transversal electric field.

Fully microcrystalline silicon, μc-Si, thin films (<100 nm) have been deposited at low temperature (60 °C) on Corning glass and plastic flexible polyimide substrates by plasma enhanced chemical vapor deposition (PECVD) using SiF4-H2-He. The effect of deposition temperature on the structure, i.e., crystallinity and density, of μc-Si films is investigated by spectroscopic ellipsometry in the 1.5−5.5 eV energy range. Modeling of spectroscopic ellipsometry data is used for highlighting crystallinity of the substrate/film interface, i.e., the absence of any amorphous incubation layer. It is found that film crystallinity does not depend on film thickness, and it increases with the decrease of deposition temperature. The temperature dependence is explained on the basis of a like-Arrhenius kinetic analysis of the etching process by atomic fluorine and hydrogen of both μc-Si and a-Si phases.

The paper discusses the wave-plasma energy coupling in cylindrical microwave discharges produced in argon, operating at frequency 2.45 GHz, average electron densities between 5×1011−3×1012 cm−3 and pressures from 10−3 to a few torr. The study focus on a special propagation mode called surface wave (SW), whose field distribution presents a maximum intensity near the discharge wall. Moreover, the influence of the space-charge sheath in the discharge energy deposition is carefully analysed. Simulation results show that the absorption of energy from the SW occurs in two different modes (convection and friction) depending on pressure, and that the transition between them is observed around 10 mtorr pressure, regardless of the electron density. The paper proposes a definition for the discharge yield, which can be of interest in optimizing the operation conditions of gas discharges for applications.

Recently, plasmas have been largely studied to develop a new cold and safe sterilization process. The plasma efficiency on bacteria destruction has been proved at low or near atmospheric pressure. In our investigation we used a N2-O2 post discharge at low pressure, where the experimental conditions allowing the optimal production of active species have been determined: 100 Watt, 1 Ln.min−1, 5 Torr. By exposing E. coli to these plasma conditions, it is demonstrated a synergy of N and O active atoms on substrate temperature: a reduction of 6 log was achieved after a treatment time of 20 minutes at 80 °C and of 12 log after 5 minutes at 120 °C.

The synthesis of low density polyethylene (LDPE) ultrahydrophobic surfaces with controlled roughness and transparency was described in a two steps O2 and CF4 plasmas treatment. Water contact angle as high as 171°, contact angle hysteresis less than 4°, and sliding angle as 4° were obtained on those surfaces. The surfaces with small roughness reached 85% of transparency between 400 nm and 800 nm of wavelength. Besides the dynamic dewetting experiments showed a particular behavior. While they were wet with water, the surfaces loosed their ultrahydrophobic properties. An explanation of this behavior was given according to both Wenzel and Cassie Baxter wetting states.

A durable water repellent, stain resistant or flame retardant character can be conferred to polyacrylonitrile (PAN) textiles by using the plasma induced graft polymerization technique. The monomers used are perfluoroalkylacrylate, (meth)acrylate phosphates, and phosphonates which are well known to be effective for the waterproofing and the fireproofing of polymeric substrates, respectively.

Results are presented on the production of oxygen atoms in flowing microwave post-discharges in a reactor of 5 litres at high pressures (10-50 torr). Diagnostics of O-atom densities are obtained by NO titration in the post-discharge. An hydrodynamic and kinetic model has been developed to obtain the spatial distribution of O-atoms inside the post-discharge reactor. Such post-discharge processes at high pressures are of interest for elastomer treatments.

Flowing post-discharges resulting from surfatron microwave discharges in nitrogen and methane gas mixture with low amount of methane (less than 1%) are implemented for nitrocarburising treatment. Atomic nitrogen and atomic carbon densities are measured in post-discharge by combining optical emission spectroscopy and NO titration. The kinetic schema leading to N and C atoms densities is presented with a special attention paid to the effect of gas temperature on the kinetic constants. The influence of different discharge parameters such as methane percentage, total pressure, methane injection upstream or downstream the discharge and gas temperature are studied by these techniques. It is shown that, except at the lowest percentage used in this study (0.02%), methane introduction decreases nitrogen atoms densities. A maximum in carbon atoms density (1013 cm−3) is found for 0.05% of methane introduced in a nitrogen discharge at 2670 Pa. The corresponding nitrogen atoms density is two orders of magnitude higher (2–3 × 1015 cm−3). We present some arguments showing that gas expansion is the only effect that gas temperature has on nitrogen atoms densities. At present, it is not clear if such explanation is also applicable to the effect of gas temperature on carbon atoms densities.