ABSTRACT: New long-pulse ion sources have been employed to extend the neutral beam pulse on TFTR from 0.5 sec to 2.0 sec. This made it possible to study the long-term evolution of supershots at constant current and to perform experiments in which the plasma current was ramped up during the heating pulse. Experiments were conducted with co and counter injection as well as with nearly balanced injection of deuterium beams up to a total power of 20 MW. The best results, i.e., central ion temperatures Tio > 25 keV and neo τE Tio values of 3 × 1020 keV sec m-3, were obtained with nearly balanced injection. The central toroidal plasma rotation velocity scales in a linear-offset fashion with beam power and density. The scaling of the inferred global momentum confinement time with plasma parameters is inconsistent with the predictions of the neoclassical theory of gyroviscous damping. An interesting plasma regime with properties similar to the H-mode has been observed for limiter plasmas with edge qa just above 3 and 2.5.
Plasma Physics and Controlled Fusion 08/2002; 29(10A):1235. · 2.42 Impact Factor
ABSTRACT: The Korea Superconducting Tokamak Advanced Research (KSTAR) project is the major effort of the national fusion programme of the Republic of Korea. Its aim is to develop a steady state capable advanced superconducting tokamak to establish a scientific and technological basis for an attractive fusion reactor. The major parameters of the tokamak are: major radius 1.8 m, minor radius 0.5 m, toroidal field 3.5 T and plasma current 2 MA, with a strongly shaped plasma cross-section and double null divertor. The initial pulse length provided by the poloidal magnet system is 20 s, but the pulse length can be increased to 300 s through non-inductive current drive. The plasma heating and current drive system consists of neutral beams, ion cyclotron waves, lower hybrid waves and electron cyclotron waves for flexible profile control in advanced tokamak operating modes. A comprehensive set of diagnostics is planned for plasma control, performance evaluation and physics understanding. The project has completed its conceptual design and moved to the engineering design and construction phase. The target date for the first plasma is 2002.
Nuclear Fusion 05/2002; 40(3Y):575. · 4.09 Impact Factor
ABSTRACT: The KSTAR (Korea Superconducting Tokamak Advanced Research)
project is the major effort of the Korean National Fusion Program to
design, construct, and operate a steady-state-capable superconducting
tokamak. The project is led by Korea Basic Science Institute and shared
by national laboratories, universities, and industry along with
international collaboration. It is in the conceptual design phase and
aims for the first plasma by mid 2002. The key design features of KSTAR
are: major radius 1.8 m, minor radius 0.5 m, toroidal field 3.5 T,
plasma current 2 MA, and flexible plasma shaping (elongation 2.0;
triangularity 0.8; double-null poloidal divertor). Both the toroidal and
the poloidal field magnets are superconducting coils. The device is
configured to be initially capable of 20 s pulse operation and then to
be upgraded for operation up to 300 s with non-inductive current drive.
The auxiliary heating and current drive system consists of neutral beam,
ICRF, lower hybrid, and ECRF. Deuterium operation is planned with a full
Fusion Engineering, 1997. 17th IEEE/NPSS Symposium; 11/1997