Spectroscopy

A brief introduction into the spectroscopy of fusion plasmas is presented. Basic principles of the emission of ionic, atomic and molecular radiation will be explained and a survey of the effects, which lead to the population of the respective excited levels, will be given. The instrumentation, which is necessary for such measurements under the conditions in tokamak and stellarator plasmas, will be described. As illustrative examples for the wide wavelength range covered the derivation of core plasma parameters, transport properties, boundary temperatures and fluxes including their molecular composition will be given.