Observation of Zeeman splitting of spectral lines and measurements of magnetic field pitch angle in KSTAR

The Zeeman splitting of the Da (656.10 nm) and the Hα (656.28 nm) spectral lines and the different impurities from deuterium/hydrogen discharges in the KSTAR tokamak plasma have been observed in the visible region of the spectrum. The internal magnetic field strength has been determined by analyzing the circular polarization of the spectral lines emitted by the plasma. The radial magnetic field is obtained by using the Abel inversion technique. In addition, the magneticfield pitch angle is derived from the polarization characteristics of the σ component of the Zeeman triplet of the H emission at 656.28 nm by using a polarization-sensitive spectroscope.