Laser-Induced Desorption of Impurities from the Macrotor Tokamak Walls

Flash heating by a laser pulse has been used to desorb loosely bound species from a spot on the tokamak wall. Spectral analysis of the suddenly increased impurity radiation from the plasma in front of the laser-heated spot gives information on the species and the amount of impurity atoms present on the surface at a specific point in time of the tokamak discharge. Loosely bound chromium has been found on the stainless-steel surface.