Speaker
Jong-Gu Kwak
(NFRI)
Description
The main mission of KSTAR program is exploring the physics and technologies of high performance steady state tokamak operation that are essential for future fusion reactor. Since the successful long pulse operation of 25sec at 0.5MA exceeding conventional tokamak capabilities in 2013, the duration of H-mode has been extended to over 50s which corresponds to a few times of current diffusion time. In addition to long-pulse operation, the plasma performance is further extended on the high betap discharge which characterizes the fully non-inductive discharge over 10s and achieves both ion and electron temperature over 5 keV simultaneously in line integrated density of 5*101919/m33.
For supporting above KSTAR performances, main heating consists of various asset of heating mixture. Especially highly tangential 6 MW NBI consisting of three ion sources and 1 MW ECCD has been played in very important role in sustaining and achieving high performance plasma as well as the startup. Innovative concept of current drive, helicon, was installed and its preliminary results shows its efficient coupling and high power system will be tested in 2016. In addition to heating systems, various diagnostics including neutron is also used for characterizing and interpreting the plasma performance. A unique 2D/3D ECE imaging diagnostics on KSTAR provided the basic underling physics of the ELMs validated with the synthetic image based on the BOUT++ code and visualized TM/NTM mode phenomina during NTM control at high beta operation.
Including above topics, the presentation will address the recent results on high ion temperature and neutron production discharge with the energy spectra of neutron and near term plan of heating upgrade in KSTAR.
Co-author
Jong-Gu Kwak
(NFRI, Daejeon, South Korea)
