The impact of light and medium mass ions in crystals in the MeV range is of particular interest in high energy implantations. In the present work, extensive continuous wave (cw) and pulsed electron paramagnetic resonance (EPR) studies of a 21R SiC Lely platelet, after irradiation with 8 MeV 7Li2+ ions in the random direction, up to a maximum dose of approximately 1 × 1016 particles/cm2 are presented. The existence of new types of defects induced in the end-of-range region of impinging ions is discussed and analyzed. Due to the complexity of the induced structure, the technique of progressive annealing was utilized, revealing interesting features in the experimental spectra. The results are compared to known literature and an attempt is made to explain the occurring similarities. Furthermore, a new paramagnetic defect was isolated and analyzed, persisting up to 1100 °C during the annealing procedure.

We analyze the ultimate performance of a superconducting quantum detector in order to meet requirements for applications in near-infrared astronomy and X-ray spectroscopy. The detector exploits a combined detection mechanism, in which avalanche quasiparticle multiplication and the supercurrent jointly produce a voltage response to a single absorbed photon via successive formation of a photon-induced and a current-induced normal hotspot in a narrow superconducting strip. The response time of the detector should increase with the photon energy providing energy resolution. Depending on the superconducting material and operation conditions, the cut-off wavelength for the single-photon detection regime varies from infrared waves to visible light. We simulated the performance of the background-limited infrared direct detector and X-ray photon counter utilizing the above mechanism. Low dark count rate and intrinsic low-frequency cut-off allow for realizing a background limited noise equivalent power of 10−20 W Hz−1/2 for a far-infrared direct detector exposed to 4-K background radiation. At low temperatures, the intrinsic response time of the counter is rather determined by diffusion of nonequilibrium electrons than by the rate of energy transfer to phonons. Therefore, thermal fluctuations do not hamper energy resolution of the X-ray photon counter that should be better than 10−3 for 6-keV photons. Comparison of new data obtained with a Nb based detector and previously reported results on NbN quantum detectors support our estimates of ultimate detector performance.

Polycrystalline iron thin films on ion-etched monocrystalline In0.5Ga0.5As/InP (001) substrates were prepared using ion-beam sputtering deposition. The interface reaction was characterised by X-ray diffraction and conversion electron Mössbauer spectroscopy experiments, after annealing in vacuum for 1 h at temperatures between 350 and 450 °C. Interdiffusion phenomena mainly result in the formation of five new phases, namely metallic-In, InAs, Fe2As, Fe2InxAs$_{1-x}$ ($0 \leq x \leq 0.2$) and Fe3Ga$_{2-x}$Asx ($x = 0.2 - 0.3$), in agreement with the predictions of the phase diagrams. InAs results from the decomposition of the semiconductor substrate and remains (001)-textured. The iron-arsenide grains grow into the substrate below the Fe/In0.5Ga0.5As interface. The In precipitates reach ~40 nm in size after 1 h annealing at 450 °C, while the Fe3Ga$_{2-x}$Asx phase appears at 400–450 °C with an either textured or disordered structure. Finally, the overall activation energy for the thermal reaction is calculated to be 1.5 eV in the latter temperature range.

The structural and transport properties of thin FePc films of various thickness deposited onto glass substrates have been studied at several temperatures. The structural studies show that the films belong to monoclinic system of β-phase. This structure is confirmed by infrared absorption analysis. The dark electrical resistivity was found to decrease with increasing the film thickness. Graphical representation of $\log \rho$ as a function of reciprocal temperature yields two distinct linear parts indicating in turn the existence of two activation energies $\Delta E_1$ and $\Delta E_2$. Measurement of the thermoelectric power showed that FePc thin films behave as p-type semiconductor over the temperature range $300{-}450$ K. Analysis of thermoelectric power connected with the resistivity results reveals some essential parameters such as: hole mobility $\mu_{\rm h} \approx 2 \times 10^{-6}$ m2 V-1 s-1, hole concentration $p \approx 5\times 10^{18}$ m-3 and the ratio $c = \mu_{\rm e}/\mu_{\rm h} \approx 0.25$. Capacitance-voltage data confirm that the Au/FePc interface does not form a Schottky barrier and measurements of the dependence of capacitance on film thickness indicate that the relative permittivity of the films is approximately 3.7. Room temperature current density-voltage characteristics showed ohmic conduction in the lower voltage range and space-charge-limited – conductivity (SCLC) in the relatively high voltage. The SCLC controlled by an exponential distribution of traps above the valence band edge. The temperature dependence of current density in accordance with the theory for the exponential trap distributions yielded some essential parameters such as: the hole mobility, the relative permittivity, the trap concentration, the characteristic temperature and the trap density.

Crystalline particles of palladium are known to form on polycrystalline Pd interacting with low-energy hydrogen ions. These particles disperse on the glassy medium called the “matrix". The particles were recently confirmed by transmission electron microscopy to be classified into two groups: the particles emerging from the projectile-implanted subsurface together with the outflowing matrix and those newly produced on the hydrogen-bombarded matrix. The latter type of particles was nucleated as a crystalline cluster on the disordered substrate, and then underwent three-dimensional growth into a nanocrystal under the bombard- ment of showering hydrogen ions. Some particles presented a bubble-like TEM contrast, independently of their growth history. Such particles were chestnut-like in structure, with a hard shell wrapping the less-dense interior, and their formation may be attributed to a chemical process occurring within the particles.

In many physical processes, there is uncertainty in the parameters which define the process and this input uncertainty is propagated through the equations of the process to its output. Experimental design is essential to quantify the uncertainty of the input parameters. If the process is simulated by a computer code, propagation of uncertainties is carried out through the Monte Carlo method by sampling in the input parameter distribution and running the code for each sample. It is then important to obtain information about the way in which the parameters are influential on the output of the process. This is useful in order to decide how to sample in the input space when propagating uncertainties and on which parameters experimental effort should be more concentrated. Here, we use dimensional and similarity analyses to reduce the dimension of the input variable space with no loss of information and profit from this reduction when propagating uncertainties by Monte Carlo. Using dimensional analysis, the output is expressed in terms of the inputs through a series of dimensionless numbers, a dimension reduction is achieved since there are less dimensionless numbers than original parameters. In order to minimize the uncertainty of the estimation of the output, propagation of uncertainties should be carried out by sampling on the space of the dimensionless numbers and not on the space of the original parameters. The purpose of this paper is an application of propagation of uncertainties to a code which simulates the interaction of metal drilling with a laser beam, where there exists uncertainty in the absorbed intensity of the beam and the density of the medium. By sampling in the reduced input space, a substantial variance reduction is achieved for the estimators of the mean, variance and distribution function of the output. Moreover, the output is found to depend on the intensity and the density through their quotient.

The sputtering rate (Q), in glow discharge, was measured as a function of the discharge power (W). An empirical relation could be obtained having the form $Q = K^{**} W^m$, with the constants $K^{**}$ and m. The equation was compared with theoretical derived equation of Takatsu and Toda, which is based on the mechanism of momentum transfer. Takatsu and Toda theoretical relationship had to be rearranged to obtain the same relationship between the sputtering rate (Q) and the discharge (W). The experimental data obtained in the present work as well as by Boumans and Takatsu and Toda were analysed on the bases of the obtained equation. This analysis revealed that the constants appearing in the Q-W equations are pressure dependent. These dependences are described and discussed.

Measurements were carried out in the temperature range 293–453 K over the frequency range 100 Hz–100 kHz on the ac electrical properties of vacuum deposited SbxS1−x thin films of different thicknesses prepared with different deposition rates. The obtained experimental data have been analyzed with reference to various theoretical models. The ac conductivity increases with frequency according to the relation σac(ω) αωs. The analysis shows that the correlated barrier-hopping (CBH) model is the most appropriate mechanism for the ac conduction in these films. The value of the dielectric constant slightly changed for higher frequencies irrespective of temperature change, whereas its value increases at higher temperature with the decrease in frequency. The dielectric loss has been found to increase with increase in temperature and decrease in frequency. The deposition rate and film thickness have a remarkable effect on ac conductivity and dielectric properties. The maximum barrier height wm is calculated from dielectric measurements according to Guintini et al. equation based on Elliott (CBH) model; which suggested the hopping of charge carriers over a potential barrier between charged defect states. The density of states was also calculated using Elliott model.

Thrust calculations of the thermally choked ram accelerator propulsive mode based on quasi-steady, one-dimensional modeling of the flow process have been quite successful in predicting the experimental velocity-distance profile when real gas corrections are applied to the combustion products of propellants at initial fill pressures up to 8 MPa. A further refinement of the modeling takes into account real gas corrections for the initial state at higher fill pressures. It turns out that the Redlich-Kwong equation of state accurately determines the thermodynamic properties of the unreacted propellant for fill pressures up to at least 20 MPa. Using this equation of state for the calculation of the sound speed for a typical ${\rm CH}_4/{\rm O}_2/{\rm N}_2$ propellant provides a 15% higher value at 20 MPa than that predicted for an ideal gas; this increase significantly affects the operating characteristics of the ram accelerator at a given velocity. The corresponding thrust maximum increases by 30%. This corrected theory is most appropriate under conditions of high pressure operation at relatively low acceleration levels; i.e., less than 10 000 g. The corrections to the aerothermodynamic equations that are discussed in this paper are fully generalized and can be applied using any equation of state.

YO molecule in the vapor phase above Y2O3 melted at the focus of a solar furnace exhibit a fluorescence phenomenon induced by absorption of the incident solar photons. The diverse spectral profiles measured at various locations from the melted surface reflect the different temperatures in the gas phase. The comparison of the measured spectra with band simulation allows to give an estimation of the upper limit temperature of the gas phase in the vicinity of the hot front.

This paper describes a 3D finite element formulation used for radiofrequency hyperthermia problems. Edge finite elements have been coupled with an absorbing boundary condition. Results are presented in term of specific absorption rate. They are compared to experimental measurements performed on a phantom having equivalent electromagnetic properties to human tissues. This comparison shows a good agreement between both numerical and experimental results. Simulations are also achieved on a heterogeneous phantom. The model is then used on a real geometry coming from computerized tomography scans.