Calculation of edge ion temperature and poloidal rotation velocity from carbon III triplet measurements on the COMPASS tokamak

Atomic spectroscopy can provide valuable information about fusion plasma. This is possible due to the fact that properties of radiated photons are governed by ion and electron velocity distributions and densities, electromagnetic fi elds, and ion species present in a plasma. Specifi cally, it can be used to calculate ion temperature and ion fl ow along magnetic fl ux surfaces in tokamaks called plasma rotation. Knowledge of these two quantities and their spatial and temporal evolution is particularly interesting for studies of plasma confi nement modes, namely, L-mode (low confi nement mode) and H-mode (high confi nement mode). A spectroscopic system lent by the Instituto de Plasmas e Fusao Nuclear, Lisboa, Portugal, was installed at the COMPASS tokamak to investigate the stated plasma properties. The system is based on high-resolution measurements of the CIII triplet at 465 nm and calculation of the ion temperature and poloidal plasma rotation from the spectral line shape and position, respectively. Analysis of measured spectra showed that an enhancement is needed to meet requirements for spatial and temporal profi les of calculated ion temperature and plasma rotation. To remove shortcomings of the system, a Calculation of edge ion temperature and poloidal rotation velocity from carbon III triplet measurements on the COMPASS tokamak Matěj Tomeš, Vladimír Weinzettl, Tiago Pereira, Martin Imríšek, Jakub Seidl