Development of the method for Thomson scattering for measurement of electron temperature evolution in the FT-1 tokamak

Nontraditional scheme of Thomson diagnostics was developed for investigation of ECR heating dynamics in the FT-1 tokamak. In includes a multiple pulse ruby laser and multi-pass system of plasma probing. Multiple pulse conditions of laser generation (4-6 pulses with 10-15 J total energy during 1 ms) are achieved with the use of passive gate in laser resonator. Application of the multi-pass probing system enabled to increase the energy of radiation, scattered in plasma, by more, than one order, and to obtain high accuracy of electron temperature measurement (∼6% at 1013 cm-3 electron density per one laser shot with 3 J energy). Electron temperature behaviour under different conditions of SHF power introduction into plasma, is investigated. Profiles of electron absorbed SHF power are determined with the use of Thomson diagnostics data