[en] Paper studies the structure and peculiarities of output signals of a pulse radar-reflectometer in the experiments with tokamak plasma. A method to analyze experimental data of pulse reflectometry taking account of the effect of density fluctuations is suggested. The results obtained by means of this method using tokamak T-11 M under ohmic conditions are compared with the results of calculating and theoretical investigations into interaction of microwave pulses with plasma density fluctuations. It is shown that correction to the position of plasma reflecting layers occurring due to neutralization of reflectometer data rather satisfactorily agrees with the correction obtained from calculations in terms of unidimensional model at discharge stationary phase

[en] A global plasma energy balance model has been investigated. The turbulent transport coefficients due to instability of trapped particles are used. It is shown that there exist steady-state conditions with temperature below 20 keV. The operation mode providing the maximum specific power for a given thermal flux to the wall has been found. For various values of injected power, the time-dependent tokamak reactor characteristics have been obtained

No abstract available

[en] Plasma drift on the periphery of a tokamak in a magnetic tube, on sides of which coins are placed, is considered. Convection caused by toroidal particle drift is taken into account. Distribution of plasma parameters in such a tube is found. Transition from the total poloidal diaphragm to a sectioned one is traced

[en] Pulse radar-reflectometer (PRR) with 32.1 GHz frequency probing wave developed in terms of T-14 program linked with investigation into global movements of plasma pinch and with conduction of routine measurements of electron density profile at all stages of T-14 discharge, is described. First experimental results obtained using T-11M tokamak and single-frequency PRR, are presented

[en] A study has been made of the current-convective plasma instability governed by variation in the impurity relative density. A nonlinear stage has been considered. Consideration is given to the model problem of plasma stability with two kinds of ions (i, z). It is assumed that plasma cylinder is in external electric and magnetic fields directed along the cylinder axis. For the outer cylinder surfaces the problem may be regarded as two-dimensional one. The plasma temperature is constant (Tsub(z)=Tsub(i)=Tsub(e)=const), and the densities of basic ions nsub(i) and impurity ions nsub(z) changes along the radius. A turbulent diffusion coefficient has been found, and it is shown that the rate of impurity penetration from walls into plasma volume in the development of the instability may increase substantially

[en] There is investigated the near-wall region in a tokamak reactor, where plasma interacts with the neutrals generated as a result of surface recombination. For the neutrals, the kinetic equation is solved taking into account ionization and charge exchange processes. Plasma is described hydrodynamically, the transport coefficients being chosen of the Bohm type as a result of the artificial turbulence in the investigated region. The distributions of plasma and neutrals parameters are determined. It is shown that the turbulent blanket can be an alternative diverter in the removal of helium and shielding the reactor wall from sputtering

No abstract available

[en] Steady state plasma flow in the scrape-off layer of a toroidal limiter is discussed. The force balance along the torus minor radius is taken into account, from which follows that the plasma pressure gradient is balanced by the ponderomotive force (1/c) j-vectorxB-vector, which arises in the presence of a current density component perpendicular to the magnetic field. The limiter has an important effect on the electric current flow in the scrape-off layer. It is shown that the electric potential and plasma density values differ from one side of the limiter to the other; this leads to plasma drift along the minor radius. The characteristic length of change in the plasma density is found to be of the order of the ion cyclotron radius calculated for a poloidal magnetic field. (author)

[en] Scrape-off layer plasma of a tokamak is considered, taking into account toroidal electric and polarization drifts of charged particles. In the shade of poloidal limiter accumulation of electric charge, caused by toroidal drift, is compensated by the current to the limiter. It is shown that near the internal boundary of the scrape-off layer radial electric current due to ion polarization drift is substantial. Distributions of the electric potential and plasma concentration in the scrape-off layer are found