Kinetics of Crystallization of Binary Melts of Eutectic-Forming Substances

The crystal nucleation and growth rates in eutectic-forming melts are experimentally determined using a universal technique for finding the kinetic parameters of processes involving phase transformations. It is shown that, with an increase in the concentration of the impurity component, the crystal nucleation and growth rates gradually decrease and reach a minimum at a eutectic point. It is confirmed that inter- and extrapolation equations known in the theory of crystallization of one-component melts can be used to obtain reliable values of the kinetic parameters in the crystallization of binary melts at large supercoolings.     

Shadow photography of supersonic objects with the help of emission from a shock wave

Arzamas-16. Translated from Fizika Goreniya i Vzryva, Vol. 29, No. 6, pp. 114–115, November–December, 1993.     

Charge Transport in Solid 4He

With the help of a new experimental technique strong anisotropy of the mobility of ions has been observed in hcp ⁴ He crystals. The mobility of positive ions in the direction of the six-fold axis is found to be 200 times higher than in the perpendicular direction. Activation energies of the mobility have been measured in both principal directions. They are equal to: 5.3K in the direction of the C₆-axis and 11K in the perpendicular direction. The behaviour of the ions' velocity in the strong electric field regime is also studied as a function of the orientation.     

Vortex motions of solid media in dynamic problems of the elasticity theory

Within the framework of a problem of constructing a mathematical theory for vortex motions of solid media, we investigated a number of problems of the dynamic elasticity theory with application of numerical and analytical approaches. The solution for a self-similar problem in the finite form is presented, which we were able to divide uniquely into potential and vortex components.     

A tandem two-stage electroionization laser facility

A Tandem electroionization laser facility consisting of two lasers with identical 10-l volumes of the active regions and different types of electron guns is described. In the first laser, a gun with a cold pointed cathode is used with an electron-current density of 1.7 A/cm² and a pulse duration of 5 μs. The second laser has a gun with a directly heated cathode and a controlled duration of the electron-beam pulse.     

Cumulation and spallation with local thermal shocks in metals disks

The contribution of two mechanisms of cumulation to the process of spallation of metal disks is studied numerically. The dimensions of the spallation zones are estimated and their location is determined as a function of the plastic and viscous properties of the material.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 58, No. 1, pp. 88–95, January, 1990.