[en] This paper presents the structural analysis developed during the TBR-2 tokamak project studies. Starting with electromagnetic interaction forces on each, toroidal and poloidal coils many structural calculations have been carried out using locally developed usual E.M. interaction codes and a finite element method stress code. Following the analysis it has been determined that there is radially inward force of 1235 kN and overturning torque of 243 kNm acting on toroidal coils. This stress and displacements due to in plane loads have been calculated using a finite element code which show that the maximum stress of 240 MPa and displacement of 0.21 mm can be present at the inner part of the toroidal field coil. (Author)

[en] Different types of ion-acoustic instabilities have been studied with a DP device. Most of them are originated in ion-beam plasma systems and recently related to ion-phase vortices. Other appears as strong wave-wave interaction. When coherent waves are launched in a plasma the mechanism of chaotic behavior is also observed. Here different kind of instability is reported in which side ban waves appear and growth when a large amplitude coherent ion wave is launched in an Argon plasma produced in a DP device. (Author)

[en] Gyroinvariant drift velocities have been obtained for non-uniform magnetic fields. A general treatment is presented here for non-uniform and variable electro-magnetic fields. Complex variables and non-analytical functions, combined with successive integration by parts, are introduced. There is no need to non-canonical variables in Hamiltonian or Lagrangian treatments. (Author)

[en] Magnetic field line diffusion in a plasma is studied on the basis of the non-linear boundary layer equations of dissipative, incompressible magnetohydrodynamics. Non-linear steady state solutions for a class of plasma parameters have been obtained which are consistent with the boundary conditions appropriate for reconnection. The solutions are self-consistent in connecting a stagnation point flow of a plasma with reconnecting magnetic field lines. The range of the validity of the solutions, their relation to other fluid models of reconnection, and their possible applications to space plasma configurations are pointed out. (Author)

[en] A numerical method that is based in kinetic theory (Vlasov-Poison equations) was developed in order to calculate the dispersion relation for the interaction between a hot cylindrical and electron beam in any temperature and density. The plasma-beam system is located in a strong magnetic field. Many examples showing the effect of the temperatures and densities on the dispersion relation are given. (Author)

[en] The spectra of highly charged ions of argon, krypton and xenon with few valence electrons have been studied in the 300-2100 Angstroem range using a pulsed-discharge tube. Isoelectronic comparisons and atomic calculations have been used in the spectral analysis. New energy levels and classified lines have been found and, in the existing level values, the uncertainty has been considerably decreased. (Author)

[en] A numerical model for the equivalent circuit of a Marx type discharge is presented. The treatment includes the effect of finite closure time of the switches which drive the generator. The role of stray capacities in the generation of several oscillations (usually ascribed to ⁿoise⁾ is discussed. The results of numerical calculations for simple configurations are presented. (Author)

[en] Multiframe holographic interferometry has been applied to a gas embedded Z-pinch driven by a 1.5 ω, 100 kV coaxial line generator. The Z-pinch is triggered by a 1.06 μm, 10 ns laser pulse, at the onset of the applied voltage. A hydrogen background pressure of 0.33 atmospheres, with a 3 cm interelectrode separation is used. The laser output is also doubled and it is passed through an optical system giving two or more pulses separated by up to 10 ns for the optical diagnostics. The complete evolution of the helical instability is observed and the main features are discussed. (Author)

[en] Tikhonov's regularization method for the solution of the integral equation of the Langmuir probe current is discussed. The application of this method in plasma measurement experiments allows to restore the real electron distribution function in a wide range of experimental conditions. The solution of this problem permits to get an improved measurement accuracy in plasma diagnostics. (Author)

[en] This work describes an experimental work that are in progress in TBR-1 tokamak about the influence of resonant helical fields on the plasma potential. TBR-1 is a small tokamak in operation in the Physics Institute of University of Sao Paulo and used for basic research, diagnostic development and personal formation. Its main parameters are: R(Major Radius) = 0.30 m; a_v(Vessel Radius) = 0.11 m; a(Plasma Radius) = 0.08 m; R/a(Aspect Ratio) = 3.75; B_φ(Toroidal Field) = 5 kG; n_e0(Central Electron Density) ≅ 7 x 10¹⁸m^-3; T_e0(central electron temperature) ≅ 200 eV. (Author)