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Thomson scattering of the core edge and divertor plasma regions of a tokamak with reactor technologies is discussed. The rationale and choice of technical solutions are given, the composition of the Thomson scattering diagnostic complex is discussed, as well as an estimate of the accuracy of measuring both electron temperature and density. Particular attention is paid to ensuring the functionality of the proposed diagnostics in the reactor mode of the tokamak operation and the results of testing diagnostic equipment in the experiments on Globus-M2 tokamak. [ABSTRACT FROM AUTHOR]

diagnostics of the plasma electron component by the metho d of Thomson scattering Te(R, t) of laser radiation makes it possible to reliably measure the spatial distributions of the electron temperature and density. One of the obstacles to the implementation of TS diagnostics in thermonuclear reactors is the distortion of the spectral characteristics of the optical system due to radiation-induced absorption and contamination of optical elements with erosion products of the first wall. As a consequence, the reliability of measurements by the TS method will decrease over time. The paper describes the method of multi-laser Thomson scattering, which will solve this problem. The results of the first experiments on the Globus-M2 tokamak are also presented. [ABSTRACT FROM AUTHOR]

Combined Thomson scattering (TS) and laser-induced fluorescence (LIF) diagnostics are being developed. The Thomson scattering and laser-induced fluorescence are laser diagnostics, with joint both probing and c-ollecting optical systems, which are the most complex and expensive parts of the diagnostic systems of large tokamaks, can be combined. Thomson scattering by free electrons is the use-proven diagnostic method for measuring profiles of important parameters of the plasma electron component (electron tempera-ture Te and electron density ne), which requires a minimum of model assumptions. Almost all existing tokamaks are equipped with one or more TS systems, and by now, considerable experience has been accumulated in practical methods for implementation of these systems. The use of laser-induced fluorescence for measuring parameters of ion and neutral plasma components is less common, also because it requires knowledge of electron parameters to calculate populations of excited levels. The joint diagnostics of the Thomson scattering and laser-induced fluorescence in divertor plasma will be used to simultaneously measure the plasma parameters necessary for fundamental understanding physics of plasma detachment from divertor plates. These parameters are: the local parameters of plasma electrons (Te, ne), ion temperature (Ti) measured from the data on emission of helium ions (HeII), as well as densities of helium atoms (na(He)) and hydrogen isotopes (na(H,D,T)). The measured parameters make it possible to calculate the following characteristics: (i) the ionization and recombination rates (using the data on Te, ne, Ti, and na(H, D, T)); (ii) the friction force of the plasma flow due to collisions with neutral particles (using the data on Ti, ni (assuming ni = ne), and na(H, D, T)); and (iii) the pressure of the oncoming plasma flow (using the data on Te, ne, Ti, and ni). The article discusses advantages of combining laser diagnostics and ways of further development of the joint diagnostcs, based on the experience of creating similar diagnostics for domestic tokamaks and the similar diagnostics developed for ITER. [ABSTRACT FROM AUTHOR]

The possibilities are considered of using the Thomson scattering diagnostics of core and edge plasmas in the tokamak with reactor technologies, which is under design. The problems are described that can be solved using the Thomson scattering diagnostics, including the possibility of controlling the plasma current profile. Technical requirements for the diagnostics are formulated. The possibilities are analyzed of its arrangement in the tokamak vacuum chamber. The accuracies are estimated of measuring the electron temperature and density of the plasma created in the tokamak. Particular attention is paid to ensuring the operability of the proposed diagnostics in the reactor regime of the tokamak operation. [ABSTRACT FROM AUTHOR]

The authors describe a diode-pumped Nd:YAG laser that produces 920 mJ output energy pulses with a pulse duration of 76 ps at 200 Hz pulse repetition rate. Second-harmonic generation with a pulse energy of 730 mJ and pulse duration of 63 ps was obtained by using LiB3O5 crystal with II-type phase matching. The output beam divergence was about 1.5 × DL (the diffraction limit) and 1.9 × DL for 1064 and 532 nm wavelengths, respectively. [ABSTRACT FROM AUTHOR]

Regenerative amplification of 946 nm pulses which are sliced from 12 mW continuous wave laser diode is reported. Near-transform-limited 2.9 ns pulses with highly stable and smooth temporal shape were obtained with the energy of 25 mJ/50 Hz and M² <1.2. [ABSTRACT FROM AUTHOR]