Impurity diagnosis of a KSTAR graphite divertor tile using laser induced breakdown spectroscopy technique

Abstract Laser induced breakdown spectroscopy(LIBS) has been tested to diagnose impurity elements on a Korea Superconducting Tokamak Advanced Research ( KSTAR) divertortile. Spectral linesof various impurity elements such as iron, chromium, and nickel were detected from the divertorsurface. The variation of spectra with consecutive laser pulses demonstrates the potential for depth profiling analysis for the deposited impurity layer. The LIBS plasma parametershave been qualitatively determined from analysis of the relative line intensities and linewidths for each element. The validity of this analysis has been checked with atomic spectral simulations.