Application of the Zeeman patterns in Ov and Hα spectra to the local plasma diagnostics of the TRIAM-1M tokamak

Abstract

The positions of emission of berylliumlike oxygen ions in the core region as well as the hydrogen atoms in the boundary region of the limiter shadow have been measured by means of the difference of the Zeeman patterns in the spectral shape in the poloidal section of the TRIAM-1M super conducting tokamak [H. Zushi et al., Nucl. Fusion 43, 1600 (2003)]. For determining magnetic field strength, the σ components of the Zeeman spectra are resolved by a linear polarizer. In addition to the emission region, the local hydrogen neutral temperature and the recycling flow velocity are measured in the boundary region, and the bulk ion temperature is measured in the core region.

Polarization resolved Hα spectra from the large helical device: Emission location, temperature, and inward flux of neutral hydrogen

“…7,9,10 Two temperature components 14,21 were also observed. In the helium experiment, 22 however, the warm components were obviously absent.…”

“…In some experiments a polarizer has been used to eliminate the or components of H ␣ line. 16,21 However, until now no attempt has been made in which the H ␣ line is observed with its polarized components resolved simultaneously in a toroidal device. In the following we report our polarization resolved observation.…”

Hydrogen transport diagnostics by atomic and molecular emission line profiles simultaneously measured for large helical device

“…In the previous works by Iwamae et al, 6,7 Balmer-a spectra measured for LHD were fitted by convolutions of Zeeman, Doppler, and instrumental profiles. Because of the steep gradient of the T e and n e distributions around LCFS as shown in Figure 2, most of hydrogen atoms are ionized and emit light around the LCFS.…”

“…6,19 The three temperature components was called as "cold," "warm," and "hot" components, respectively. They attributed the origin of the multi temperature components to the various production processes of the atoms, such as dissociations, charge exchanges, or reflections at the walls.…”

“…5 The method has been expanded to multiple LOSs measurements for more spatial information by Shikama et al in TRIAM-1 M tokamak. 6 Iwamae et al combines a polarization-resolved spectroscopic technique with the Zeeman split analysis method for increasing the measurement accuracies. 7,8 They have measured the Balmer-a line shape for large helical device (LHD) with eight LOSs with their polarization resolved.…”