Condition for a time-constant current in a high-current planar diode

The conditions required to achieve a constant current from an explosive cathode during the pulse in a high-current planar diode are calculated. Pis’ma Zh. Tekh. Fiz. 24, 63–69 (March 12, 1998)     

Global stochastic particles in a field-reversed configuration

This paper discusses the dynamics of the fusion products of the D-He³ reaction in a field-reversed configuration, with application to a reactor regime with a large value of the plasma β. It shows that, under the conditions in the Artemis-L design [H. Momota and Y. Tomita, J. Plasma Fusion Res. 69, 801 (1993)], the motion of protons with an initial energy of 14.1 MeV is strongly stochasticized. The confinement time of these particles and the energy transfer from the fusion products to the plasma are very small. Pis’ma Zh. Tekh. Fiz. 23, 37–39 (November 12, 1997)     

Undamped self-oscillations in a compensated semiconductor under conditions of impurity breakdown in the presence of a magnetic field

Conditions for the generation of undamped self-oscillations in a compensated semiconductor in the presence of a magnetic field are studied. Pis’ma Zh. Tekh. Fiz. 23, 62–66 (August 26, 1997)     

Formation of dense electron beams in a gun with a plasma anode based on a reflecting discharge

A method of obtaining low-energy, high-current electron beams in a gun with a plasma anode based on a reflecting discharge is proposed and implemented for the first time. Pis’ma Zh. Tekh. Fiz. 23, 42–46 (May 26, 1997)     

Magnetoplasmon modes in the response of a mesoscopic particle of a semimetal or a nonmagnetic insulator

The macroscopic features of the behavior of a mesoscopic particle in a magnetic field are investigated for mesoscopic particles possessing the properties of a semimetal or a nonmagnetic insulator. It is shown that for a fixed value of the magnetic field the frequency of the Alfve’n magnetoplasma mode falls off monotonically (as 1/R) as the radius of the particle increases. Pis’ma Zh. Tekh. Fiz. 23, 16–21 (December 12, 1997)     

Formation of a diamond-like phase under conditions of preferential deposition of nondiamond carbon in a microwave gas discharge plasma with electron cyclotron resonance

Films with crystallite sizes up to approximately 0.5 μm were obtained. Results of complex investigations of these films are presented. Pis’ma Zh. Tekh. Fiz. 24, 25–31 (February 26, 1998)     

Possible emission of supermodes in a free electron laser with a transversely developed interaction space

A theoretical analysis is made of the formation of the transverse field profile in a free electron laser with an oversize planar-geometry Bragg cavity driven by a ribbon electron beam. It is shown that cw spatially coherent lasing may be achieved with an oversize parameter of the order of 50 with the excitation of supermodes comprising a set of “ cold” waveguide modes. Pis’ma Zh. Tekh. Fiz. 25, 28–34 (March 12, 1999)     

Laser control of the state of a plasma in a selective optical trap

Laser cooling of resonant ions is shown to be applicable to the effective control of the temperature of charged particles in a low-temperature electron-ion plasma confined in a magnetic trap. Pis’ma Zh. Tekh. Fiz. 23, 28–32 (January 26, 1997)     

Formation of a cathode crater in a low-voltage cold-cathode vacuum arc

The cathode crater in a low-voltage cold-cathode vacuum arc is planar. The area of the crater and the density of the current flowing through it depend on the thermal and electrical properties of the cathode metal. Pis’ma Zh. Tekh. Fiz. 24, 14–19 (July 12, 1998)     

Formation of macroparticle charge in a classical Coulomb plasma

An expression is derived for the average macroparticle charge and the electron temperature in a heated dense gas. Pis’ma Zh. Tekh. Fiz. 25, 52–55 (January 12, 1999)     

Thermomechanical effect in a cylindrically-hybrid nematic liquid crystal

Thermomechanical rotation of a cylindrically-hybrid nematic liquid crystal in the presence of a longitudinal temperature gradient is predicted theoretically and detected experimentally. Pis’ma Zh. Tekh. Fiz. 25, 71–73 (March 26, 1999)     

Heating of a current filament and formation of constrictions in a pulsed vacuum discharge

It is shown that a rapid current rise in a pulsed vacuum discharge is accompanied by enhanced compression of the current filament by its self-induced magnetic field. As a result, a constriction forms at a distance L≃1 mm from the cathode and the electron temperature increases to 10²–10³ eV at currents of order 1 kA. This behavior explains the observed increase in the degree of ion charge and the appearance of x-rays as the current pulse length decreases. The criterion for a rapid rise is the condition τ<L/V≃10⁻²⁷ s, where τ is the characteristic current amplification time and V≃10⁶ is the velocity of the cathode plasma. Pis’ma Zh. Tekh. Fiz. 24, 50–56 (September 26, 1998)     

Controlling spatiotemporal chaos in a chain of bistable oscillators

The processes in coupled oscillators and their control under bistability conditions are considered. The possibility of stabilizing spatially homogeneous states is demonstrated. Pis’ma Zh. Tekh. Fiz. 25, 51–57 (June 26, 1999)     

Suhl Instability as a Mechanism of the Catastrophic Relaxation in the Superfluid 3He–B

In order to explain catastrophic relaxation, bulk mechanism based on Suhl instability (J. Phys. Chem. Solids 1, 209, 1957) is studied. It is shown, that at sufficiently low temperatures homogeneous precession of spin becomes unstable in the whole region of tipping angles of spin 0≤β≤π. In comparison with the previous publication of Surovtsev and Fomin (J. Exp. Theor. Phys. Lett. 83, 410, 2006) the leading zero temperature increments for the angles θ ₀≃104°≤β≤π are found. Estimation of the temperature of transition to the unstable state for the angle of 105°, that corresponds to the region of tipping angles in homogeneously precessing domain (HPD), is made.     

Shear viscosity in a binary system with a spinodal

An analysis is made of the temperature-concentration dependence of the viscosity of a binary liquid in contact with a solid wall. The region of liquid-wall contact is analyzed using the multilayer Ono-Kondo model. It is shown that in the temperature-concentration range bounded by a spinodal, the viscosity increases abruptly. Pis’ma Zh. Tekh. Fiz. 24, 58–63 (November 26, 1998)     

Depth of penetration of microindenters in a metal target subjected to a fast powder flux

Results are presented of experiments to determine the maximum depths of superdeep penetration and to check the conclusions of an existing model of this effect. Pis’ma Zh. Tekh. Fiz. 25, 69–73 (April 12, 1999)     

Stressed state of a matrix and an inclusion made from a twisted composite superconductor in cladding when a circular current interacts with a magnetic field

This paper discusses the stressed state of the matrix and a long wire made from a twisted multicore composite superconductor and encased in cladding when the circular component of the transport current interacts with a magnetic field. Pis’ma Zh. Tekh. Fiz. 24, 1–6 (January 26, 1998)     

Flow in a turbulent supersonic boundary layer with a heat source

A numerical analysis is made of a turbulent supersonic boundary layer with a heat source for a wide range of heat supplied to the gas. It is shown that the frictional resistance may be reduced appreciably and the efficiency of using a heat conductor to achieve such a reduction is estimated. Pis’ma Zh. Tekh. Fiz. 25, 38–42 (April 12, 1999)     

Investigation of a glow discharge in a mixture of Ar and OH

A glow discharge in a mixture of argon and hydroxyl (OH) is investigated experimentally. It is shown that under certain discharge conditions a considerable portion of the electrical energy imparted to the discharge is used to generate resonant emission of OH molecules. The results obtained point to a realistic possibility of creating a new, ecologically friendly source of optical radiation, which can replace mercury lamps in the near future. “Applied Chemistry” State Scientific Center Pis’ma Zh. Tekh. Fiz. 25, 62–66 (April 26, 1999)     

Stability of a charged bubble in a dielectric liquid against radial perturbations

It is shown that the critical conditions for instability of a charged vapor-gas bubble in a dielectric liquid against virtual radially symmetric volume perturbations are substantially less stringent than the critical conditions for it to be unstable against virtual distortions of the shape. Pis’ma Zh. Tekh. Fiz. 25, 25–29 (January 12, 1999)