Leonid E. Zakharov

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Extensive lithium wall coatings and liquid lithium plasma-limiting surfaces reduce recycling, with dramatic improvements in Ohmic plasma discharges in the Current Drive Experiment-Upgrade. Global energy confinement times increase by up to 6 times. These results exceed confinement scalings such as ITER98P(y,1) by 2-3 times, and represent the largest increase(More)
The theory of perturbed magnetohydrodynamic equilibria is presented for di erent formulations of the tokamak equilibrium problem. For numerical codes, it gives an explicit Newton scheme for solving the Grad-Shafranov equation subject to di erent constraints. The problem of stability of axisymmetric modes is shown to be a particular case of the equilibrium(More)
This paper describes the effect and gives the theory of magnetic propulsion which allows driving free surface plasma facing liquid lithium streams in tokamaks. In the approximation of a thin flowing layer the MHD equations are reduced to one integrodifferential equation which takes into account the propulsion effect, viscosity, and the drag force due to(More)
In the advanced tokamak scenarios, plasma performance is strongly limited by the External Kink Mode (EKM) which, coupled inductively with a resistive wall, is transformed in a Resistive Wall Mode (RWM). In this paper we present our contribution to calculations of RWMs in diverted tokamak configurations. By choosing a coordinate system with straight field(More)
The current drive experiment-upgrade (CDX-U) at the Princeton Plasma Physics Laboratory has begun experiments with a fully toroidal liquid lithium limiter. CDX-U is a compact (R 1⁄4 34 cm, a 1⁄4 22 cm, Btoroidal 1⁄4 2 kG, IP 1⁄4 100 kA, Teð0Þ 100 eV, neð0Þ 5 10 m ) short-pulse (<25 ms) spherical torus with extensive diagnostics. The limiter, which consists(More)
Progress from global gyrokinetic simulations in understanding the origin of intrinsic rotation in toroidal plasmas is reported. The turbulence-driven intrinsic torque associated with nonlinear residual stress generation due to zonal flow shear induced asymmetry in the parallel wave number spectrum is shown to scale close to linearly with plasma gradients(More)
The lithium tokamak experiment (LTX) is a modest-sized spherical tokamak (R(0)=0.4 m and a=0.26 m) designed to investigate the low-recycling lithium wall operating regime for magnetically confined plasmas. LTX will reach this regime through a lithium-coated shell internal to the vacuum vessel, conformal to the plasma last-closed-flux surface, and heated to(More)