In this paper we study some high-current equilibria of the FAST tokamak, in order to analyse potentially dangerous ideal MHD instabilities of such low-q configurations, in view of their passive and active stabilization. Introduction The FAST device is presently under discussion as a possible DEMO and ITER satellite [1]. The main FAST goals are: exploring plasma wall interaction in reactor relev...

The idea of new diagnostics method for the small-scale irregular structures of magnetically confined plasma is suggested in the present paper. The method can be based on measurements of intensity attenuation of the normal sounding waves. Anomalous attenuation arises due to multiple scattering effects investigated earlier for ionospheric radio propagation. It has been shown that multiple scatter...

The first successful high power heating of a high dielectric constant spherical tokamak plasma by an electron Bernstein wave (EBW) is reported. An EBW was excited by mode conversion (MC) of an mode cyclotron wave injected from the low magnetic field side of the TST-2 spherical tokamak. Evidence of electron heating was observed as increases in the stored energy and soft x-ray emission. The incre...

The use of relativistic electron beams for supplementary heating of tokamaks to ignition temperatures is discussed, under the assumption that they can be successfully injected. It is shown that if an electron beam with presentstate-of-the-art power, but longer pulse length, can be injected into an Ohmically pre-heated tokamak plasma, it transfers its energy to the plasma on a time-scale short e...

To improve poloidal rotation measurement capabilities on the DIII-D tokamak, new chords for the charge exchange recombination spectroscopy (CER) diagnostic have been installed. CER is a common method for measuring impurity rotation in tokamak plasmas. These new chords make measurements on the high-field side of the plasma. They are designed so that they can measure toroidal rotation without the...

The control of sawtooth oscillations is an active area of tokamak research. Large sawtooth oscillations need to be avoided in ITER, since these large sawteeth couple to neoclassical tearing modes and edge localized modes resulting in serious confinement degradation. Small sawtooth oscillations, however, may be beneficial in preventing impurity and helium ash accumulation in the center of the pl...

A 1 MW� 2 msec pulse of rf power at the ion cyclotron frequency (2.6 MHz) has been used to heat the ions from < 1 eV to 350 eV in a toroidal octupole device. The ion temperature is limited by charge exchange loss and agrees quantitatively with theoretical predictions. No parametric decay waves, enhanced diffusion, or other deleterious effects except for a high neutral re­ flux are observed to a...

Social acceptance of fusion reactors depends largely on their economic viability. To investigate this issue, we estimate and compare the cost of electricity (COE) among D-T, D-3He, and D-D fusion reactors. Three types of confinement systems are evaluated: the tokamak reactor (TR), the spherical tokamak reactor (STR), and helical reactor (HR). For each reactor type, COE parameter surveys are per...

Abstract. This paper deals with the numerical reconstruction of the plasma current density in a Tokamak and of its equilibrium. The problem consists in the identification of a non-linear source in the 2D Grad-Shafranov equation, which governs the axisymmetric equilibrium of a plasma in a Tokamak. The experimental measurements that enable this identification are the magnetics on the vacuum vesse...

1 Tokamak fuelling using high velocity compact torus (CTs). Compact toroids (CTs) are self-organized magnetized plasmoids in a nearly force-free Taylor state. In the laboratory, CTs can be formed using coaxial electrodes and a solenoid magnetic field coil. The resultant CT equilibrium is sufficiently robust that it can withstand extremely large acceleration (>1 x 10 g) and can achieve high fina...