AbstractIn tokamaks, small variations in the magnetic field create ripple. The discontinuous nature of the magnetic field coils in an axisymmetric torus conduces to additional particle trapping, and it is responsible for an additional neoclassical diffusion. Ripples also reduce the particle removal efficiency and disturb plasma confinement and cause constraints in the design of magnet of fusion reactor. Therefore, it is quite important to include the ripple for the design of plasma edge components. Herein, several considerations are taken into account to calculate and evaluate the diffusion coefficient and ion heat conductivity in ripple transport and also to compare it with neoclassical mode. پرونده مقاله

AbstractSeveral theoretical and experiential studies of runaway electrons in the well-known Tokamaks of the world have been made over the past few decades. In the present study, the measurements of runaway electrons energy were carried out by a new runaway probe in the IR-T1 Tokamak. In the IR-T1 Tokamak, the hard X-ray diagnostic system is used as a diagnostic global measurement system at the vessel wall of Tokamak. Runaway probe was first designed and fabricated for local measurement near the plasma edge in IR-T1 Tokamak. The new diagnostic has the advantage that the local interaction of runaways with materials can be evaluated, along with the direct measurement of the runaway electrons. The runaway probe consists of 2 LYSO (Lu 1.8Y.2SiO5:Ce) crystals covered by a graphite housing which is shielded by tungsten filter placed in the direction of runaway electrons. The main elements of the runaway probe are LYSO crystals which convert the energy of runaway electrons into visible light which is instructed to silicon photomultipliers. The present study aimed to evaluate a new runaway probe in the IR-T1 Tokamak to detect beta and gamma rays. The results indicated that electron spectrum is between 500 keV and 2 MeV at the plasma edge in the IR-T1 Tokamak. پرونده مقاله

AbstractPhysical properties of transparent and conducting indium tin oxide (ITO) thin films grown by radiofrequency (RF) magnetron sputtering are studied systematically by changing deposition time. The X-ray diffraction (XRD) data indicate polycrystalline thin films with grain orientations predominantly along the (2 2 2) and (4 0 0) directions. From atomic force microscopy (AFM) it is found that by increasing the deposition time, the roughness of the film increases. Scanning electron microscopy (SEM) images show a network of a high-porosity interconnected nanoparticles, which approximately have a pore size ranging between 20 and 30 nm. Optical measurements suggest an average transmission of 80 % for the ITO films. Sheet resistances are investigated using four-point probes, which imply that by increasing the film thickness the resistivities of the films decrease to 2.43 × 10−5 Ω cm. پرونده مقاله

The demand is increasing for the production of sugar required by the pharmaceutical industry and the production of baby food due to higher quality standards compared to the sugar consumed by the food industry. Nevertheless, the possibility of undesirable changes due to the acceleration and effect of thermal processes has caused more attention to non-destructive and non-thermal methods in production of this product. This research conducted with the aim of evaluating the effects of lyophilization process on the production of pharmaceutical sugar as a complementary and hybrid process in addition to conventional thermal methods. Results show that by applying conditions of temperature, pressure and time in lyophilization operation, in terms of temperature conditions of -42°C, time of 24 hours and pressure of 0.1 mm bar, it is possible to produce pharmaceutical sugar, in compliance with microbial standards and no significant changes in standard range of other quality parameters of sugar. پرونده مقاله