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Spherical tokamak plasmas are typically overdense and thus inaccessible toexternally-injected microwaves in the electron cyclotron range. Theelectrostatic electron Bernstein wave (EBW), however, provides a method toaccess the plasma core for heating and diagnostic purposes. Understanding thedetails of the coupling process to electromagnetic waves is thus important bothfor the interpretation of microwave diagnostic data and for assessing thefeasibility of EBW heating and current drive. While the coupling is reasonablywell-understood in the linear regime, nonlinear physics arising from high inputpower has not been previously quantified. To tackle this problem, we haveperformed one- and two-dimensional fully kinetic particle-in-cell simulationsof the two possible coupling mechanisms, namely X-B and O-X-B mode conversion.We find that the ion dynamics has a profound effect on the field structure inthe nonlinear regime, as high amplitude short-scale oscillations of thelongitudinal electric field are excited in the region below the high-densitycut-off prior to the arrival of the EBW. We identify this effect as theinstability of the X wave with respect to resonant scattering into an EBW and alower-hybrid wave. We calculate the instability rate analytically and find thisbasic theory to be in reasonable agreement with our simulation results.

Recent measurements of microwave and x-ray emission during edge localized mode (ELM) activity in tokamak plasmas provide a fresh perspective on ELM physics. It is evident that electron kinetics, which are not incorporated in standard (fluid) models for the instability that drives ELMs, play a key role in the new observations. These effects should be included in future models for ELMs and the ELM cycle. The observed radiative effects paradoxically imply acceleration of electrons parallel to the magnetic field combined with rapid acquisition of perpendicular momentum. It is shown that this paradox can be resolved by the action of the anomalous Doppler instability which enables fast collective radiative relaxation, in the perpendicular direction, of electrons accelerated in the parallel direction by inductive electric fields generated by the initial ELM instability.

This paper presents the results of analysis of work-rest cycles of the Salyut-6 and Salyut-7 prime crewmembers. The distribution of work-rest cycles within the day, week, month and the flight as a whole, their relation with other components of the time schedule, the effect of various factors involved on the health status and work capacity were studied. It was shown that specified work-rest cycles should be rigorously adhered to. It was demonstrated that proper planning and realization of work-rest cycles, as well as their correction during actual flight with respect to psychophysiological and biorhythmological variations are required to maintain good health condition and high work capacity of crewmembers.