Laser Spectroscopy Measurements Methods of Divertor and Edge Plasma Parameters

Development and proof-of-principle experiments by laser spectroscopy (LS) methods have been carried out in Kurchatov Institute as part of program of developing diagnostics techniques for ITER divertor plasmas. In experiments which have been made on PNX-U multipole magnetic trap the testing of diagnostics methods were combined with plasma studies in this machine. Today's concept of ITER program includes making use impurity-seeded plasma experiments. It's possible to use injected extrinsic impurities (Ne, Ar, Kr) for Doppler measurements of temperatures by LS-technique. Measurement of atom and ions temperatures in divertor plasmas is important but difficult problem because ITER Requirement for Measurements defines range for Ti,a to be 0.3<T<200 eV. It means necessity to measure low values of temperature with good spatial resolution. Series of Ti(Ar''1+) measurements have been carried out by scanning laser line across absorption line profile of the ion; fluorescence light has been detected at another wavelength. The experimental Ti values are in the range of 4<Ti<25 eV. Anomalous heating of ions have been discovered during the studies. When helium puffing into discharge was used, Doppler measurement of He I temperature has been measured by scanning across 587.6-nm line profile: summarizing of fluorescence signals at 389-nm line gives input data for estimation of He I density via interpretative CR-model. Collisional transfer of excitation from 3 ''3D energy level of He I to 3 ''3P and 3 ''3 S levels give rises to radiation of two florescence lines. The CRM was used to calculate intensity ratio of the lines as function of electron density. The diagnostic has been used for the first time in PNX-U experiments for measurements of local electron densities. This method of low ne values (Ne<10''19 m ''-3) measurements with high spatial resolution could be applied in plasma edge studies, plasma processing devices etc. (Author)