[en] The experimental results are presented on the plasma parameters and hysteresis effect for magnetron discharge produced in reactive gas mixture as Ar/N₂ and Ar/O₂ with copper, and titanium target. Most of the primary fast electrons are trapped by local magnetic field in front of the cathode, while the electron population in the unmagnetized plasma region can be approximated as bi-Maxwellian one with their temperature in the range of about 0.5 eV to 1 eV for cold electrons and in the range of 3 eV to 12 eV for hot electrons, respectively. The hysteresis effect was studied with the use of a method based on time variation of the potential and/or current of the discharge. Enhancing and diminishing of the hysteresis area can be obtained versus time rate of increasing and decreasing respectively of the cathode potential or of the discharge current. A qualitative description of the hysteresis is proposed starting from the symmetry breaking in the evolution of both surface and volume phenomena following the relaxation processes after rapidly increasing and decreasing, of the discharge current. (author)

No abstract available

[en] This paper deals with a study on the radiolysis of water in the presence of certain oxides: BeO, SiO₂, TiO₂, ZrO₂ acting as catalysts for the hydrogen production. A radionuclide of ⁶⁰Co with an activity of about 5x10⁴ Ci was employed as an irradiation γ source. A considerable increase (up to ten times or more) of the amount of hydrogen resulting from the radiolysis of water in the presence of the above mentioned oxides was noticed in comparison with a reference sample, irradiated under the same experimental conditions, but without any catalyst. The radiolysis products have been identified by means of a method based on mass spectrometry

[en] A new processing method of the probe characteristic in the approximation of a plasma with two Maxwellian groups of electrons is proposed. Besides electron component of the probe characteristic the method asks to know its first and second derivatives. The method gives exact relations for temperature and densities of these two groups of electrons. Moreover, the method allows to specify the range of the electron energy in which the approximation of two Maxwellian groups of electrons is valid. Considerations on both numerical and experimental errors are made. The results are compared with those obtained by other methods used for processing of the probe characteristics. (authors)

[en] Experimental results are presented concerning the electron distribution function (EDF) in a planar magnetron discharge with aluminum target and argon gas. The EDF was obtained by Druyvensteyn method using a spherical probe. Axial and radial distributions of the both plasma potential and the EDF were registered. The EDF dependence on discharge current has also been obtained. (authors)

[en] Experimental results are presented concerning the electron distribution function (EDF) in a planar magnetron discharge with aluminium target and argon gas. The EDF was obtained by the Druyvensteyn method using a spherical probe. Dependence of the EDF on the discharge current was analyzed.Axial and radial distributions of plasma parameters as electron densities and temperatures and plasma potential were obtained using both EDF and direct fit method. (authors)

[en] Understanding of electronics and software requirements for developing analytical instruments and expertise in providing them gained out of indigenous analytical instrument development is successfully applied to develop a multichannel data acquisition system for an Atomic Emission Spectroscopic technique based polychromator to carry out Nuclear Fuel Characterisation. As the IC technology evolved, complex chips are developed offering various functions on a single chip. One such technology is Programmable System on Chip (PSoC). It offers very low cost and compact solution to the embedded computer system developers. PSoC chips include a CPU core and integrated analogue and digital interfaces. This paper discusses the development of PSoC based 16 channel data acquisition system (DAS) for a multichannel spectrometer and its testing with simulated signals

[en] Linear plasma generators are plasma devices designed to study fusion-relevant plasma-surface interactions. The first requirement for such devices is to operate with adjustable and well characterized plasma parameters. In the linear plasma device Magnum-PSI, the distribution of the charged particle flux across the target surface can be tailored by the target bias. The process is based on the radial inhomogeneity of the plasma column and it is evidenced by electrical measurements via a 2D multi-probe system installed as target. Typical results are reported for a hydrogen discharge operated at 125 A and confined by a magnetic field strength of 0.95 T in the middle of the coils. The probes were biased in the range of  −80 to  −25 V, while the floating potential of the target was about  −35 V. The results were obtained in steady-state regime of Magnum-PSI, being time-averaged over any type of fluctuations. Depending on the relative value of the target bias voltage with respect to the local floating potential in the plasma column, the entire target surface can be exposed to ion or electron dominated flux, respectively, or it can be divided into two adjacent zones: one exposed to electron flux and the other to ion flux. As a consequence of this effect, a floating conductive surface that interacts with an inhomogeneous plasma is exposed to non-zero local currents despite its overall null current and it is subjected to internal current flows. (paper)

[en] The linear plasma generator Magnum-PSI was designed for the study of plasma–surface interactions under relevant conditions of fusion devices. A key factor for such studies is the knowledge of a set of parameters that characterize the plasma interacting with the solid surface. This paper reports on the electrical diagnosis of the plasma beam in Magnum-PSI using a multi-probe system consisting of 64 probes arranged in a 2D square matrix. Cross-section distributions of floating potential and ion current intensity were registered for a hydrogen plasma beam under various discharge currents (80–175 A) and magnetic field strengths (0.47–1.41 T in the middle of the coils). Probe measurements revealed a high level of flexibility of plasma beam parameters with respect to the operating conditions. (paper)

[en] An RF magnetron plasma-enhanced chemical vapor deposition system with variable magnetic field (MagPECVD) was utilized for high rate deposition of diamond-like carbon thin films. Deposition rate was nonuniform, with minimum value of 30 nm/min in the center of the cathode where the low ionic flux is determined by the absence of the E x B electronic drift. The highest value of 1029 nm/min was registered in the position of the cathode with the highest ion flux determined by the presence of the E x B electronic drift. Hardness, elastic modulus and RMS roughness of thin films were dependent on local values of magnetic field intensities and the values of input power