In situ analysis of impurities deposited on the tokamak flange using laser induced breakdown spectroscopy

The impurity materials deposited on the plasma exposed surface of the flange in Aditya tokamak have been identified using laser induced breakdown spectroscopy. The spectral lines of Fe, Cr, Ni, Mn, Mo, Cu and C are detected in the coated layer of the flange. Intensity variation of spectral lines with successive number of laser shots has been studied. The concentrations of elements present in successive laser shot (1st to 12th) have been determined using CF-LIBS technique. Although, the intensity of the spectral lines in 1st and 12th laser shots are entirely different but relative concentration of constituents are similar. This anomalous behavior may be due to different nature of the matrices of 1st (coated layer) and 12th laser shot (flange material). Present study clearly demonstrates the capability of CF-LIBS to study the two different natures of the samples but having similar relative concentration of the constituents.