Analysis of dynamic pull-in voltage and response time for a micro-electro-mechanical oscillator made of power-law materials

Nonlinear Dynamics - Analysis of dynamic pull-in voltage for a micro-electro-mechanical oscillator of platform type is performed. The lumped mass model for the actuated micro-cantilever beam made...     

Activation of a semiconductor surface by a pulsed magnetic field

The possibility of semiconductor surface activation, which shows up as a long-term increase in the adsorption capacity in response to a short exposure to a pulsed magnetic field, is demonstrated for the first time. Magnetic-field-induced surface activation is studied on silicon, germanium, and gallium arsenide crystals. The effect revealed extends the capabilities of thin-film growth on the semiconductor surface.     

Influence of weak pulsed magnetic fields on triglycine sulfate crystals

The influence of weak (≤0.02 T) pulsed magnetic fields on the ferroelectric and dielectric characteristics of nominally pure triglycine sulfate crystals was detected for the first time. A short-term (seconds) pulsed magnetic impact caused long-term (hundreds of hours) changes in the coercive field and the temperature dependences of the dielectric constant, the dissipation factor, and the relaxation time of the dielectric constant near the ferroelectric phase transition. It was assumed that the effects detected were caused by unpinning of domain walls and dislocations from stoppers, followed by the formation of new defect and domain structures.     

Methods for reconstructing equilibrium plasma configurations in the Globus-M spherical tokamak

A magnetic diagnostics allowing one to reliably reconstruct equilibrium plasma configurations in a tokamak over a wide range of operating parameters is developed. The accuracy of determining the geometrical parameters and thermal energy of the tokamak plasma is analyzed in detail. The experimental data obtained in the Globus-M tokamak are processed the with help of the EFIT code. The influence of the plasma configuration on the intensity of the main impurity lines is investigated.     

Isothermal relaxation of non equilibrium charge in a dielectric (the case of weak charge-carrier trapping)

The features of the isothermal discharge of a dielectric containing single-energy traps after a voltage pulse V₀(t_u) is applied to the specimen, during which charge carriers (electrons) are injected into the volume of the dielectric (monopolar injection), are considered. The initial stage of the discharge is analyzed at instants comparable with the time of flight of free carriers, and also the discharge under conditions of self-consistent variation of the internal field and the volume charge in the dielectric when the external field is switched off and only the pulling field e₁ s e₀ remains. Analytical expressions are obtained which describe the change in the total current, the displacement current, and the conductivity, and also the variation of the total charge with time, by means of which one can estimate experimentally the main parameters of the material: E_t, v,, n_t.Translated from Izvestiya Vysshykh Uchebnykh Zavedenii, Fizika, No. 5, pp. 27–32, May, 1984.