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Novel concept of the longitudinal plasma flow suppression by active plasma pumping in helicoidal magnetic field in mirror traps was proposed recently. Concept exploration device SMOLA is now being constructed to prove the possibility of the suppression and determine basic scalings of ist effectiveness. Technical solutions of the SMOLA device are described in the article. Vacuum system, magnetic system, plasma source and the source of the radial electric field are discussed. Estimations of the biasing required for optimal confinement are given. Physical program fort he first experiments is also proposed.

The review presents experimental studies of plasma-surface interaction and materials behavior under plasma loads done in the multiple-mirror trap of the GOL-3 facility. In the experiments for the PSI, the energy density in the extracted plasma stream varies from 0.5 to 30 MJ/m2. Parameters of near-surface plasma measured by a set of diagnostics are reviewed. Surface patterns of targets exposed to the plasma are analyzed. The erosion depth depends on the energy loads—it rises from 0 to 600 μm at 0.5 and 30 MJ/m2, correspondingly. Cracking and evolution of graphite and tungsten surface morphology are discussed. The enthalpy of brittle destruction of graphite (10 kJ/g), which determines the threshold of bulk damage of targets irradiated with a charged-particle flux with large penetration depth, was determined. Comparison of different facilities for PSI studies are presented. Heat flux play a key role to the target surface erosion.

The study is devoted to tungsten surface modification after irradiation at the GOL-3 facility with plasma loads corresponding to the ITER type I ELMs. In order to emulate heating with a steady plasma flux in the ITER divertor, some of the tungsten samples were preheated up to 500 °C. It was found out that the behavior of the surface modification (the crack pattern and the number of bubbles) depends on the initial temperature of the targets. While the orientation of major crack networks correlates with the direction of machining of the samples. Afterwards we have observed the process of craters’ formation caused by dust particle impacts.

A novel concept of helical mirror confinement with active axial and radial plasma flow control is discussed. The idea relies on the retarding force that appears when biased plasma experiences rotation in crossed electrical and helical mirror magnetic fields. Preparations for its experimental study started in Budker Institute of Nuclear Physics, Novosibirsk. Possible parameter space for a concept-exploration-class device SMOLA is identified. Details of numerical optimization of the magnetic structure of the device are presented. The main physical task for the SMOLA experiment will be direct demonstration of the helical mirror performance in simple experimental conditions at reasonably low plasma parameters.