Scanning electron microscopy, X-ray electron probe analysis, and X-ray phase analysis are used to investigate the surface structure of W-1% La 2 O 3 alloy after irradiation with submicrosecond pulses of deuterium ions and high-temperature deuterium plasma in a Plasma Focus installation for simulation of a plasma disruption in the ITER tokamak. It is established that melting of the tungsten surface and formation of micro-cracks take place under irradiation with a power flux density up to 10 12 W/cm 2 . Introduction of La 2 O 3 particles in the alloy leads to the formation of complex La-W-O oxides with lower melting points, which results in the formation of a nonuniform structure affecting the high-temperature response of the material.

Interdiffusion in a Cu-Ni-Fe system was studied at a temperature of 1000°C for three different diffusion couples. It has been shown that, in the studied diffusion couples, the distributions of some components of the system have a distinctly nonmonotonous character and, apart from the local extremes of the concentration curves, there are also zero flux planes in five diffusion zones. Special features of the behavior of the concentration curves and diffusion paths are discussed using thermodynamic data for the system. It has been found that diffusion fluxes of the components are unambiguously associated with a derivative of thermodynamic activity by the concentration taken along the diffusion path. There are experimental data in the appendix concerning the concentration profiles for all of the studied components of the diffusion couples.

Changes in the structure and phase composition of low-activated Cr-Mn austenite and 9Cr ferrite steels exposed to high-power nanosecond pulses of high-temperature nitrogen plasma and swift nitrogen ions (desk-size plasma focus devices, 106–109 W/cm2) are observed.

Dependences of the parameters of interdiffusion (effective coefficients, diffusion paths, Kirkendall shift) on the variation of the initial compositions of a diffusion couple have been studied on the concrete example of the Co-Fe-Ni system. The experimental results obtained show that the diffusion paths in the three-component system depend substantially on the selection of initial conditions, even when the initial alloys of the “narrower” diffusion couple lie on the diffusion path of the “wider” pair. At the same time, when represented in reduced concentrations, the diffusion paths of all these diffusion couples practically coincide. The latter makes it possible to predict the type of diffusion paths for any diffusion couple whose initial com- position lies in the same concentration region. In one of the diffusion couples studied, the instability of the Kirkendall plane was revealed, which thus far was observed only in binary systems.

The paper presents measuring techniques and results of experiments performed within the PF-1000 PlasmaFocus facility in order to investigate the interaction of high-energy deuteron beams (of E-D >100 keV) and deuterium plasma streams (of v(str) >= 10(7) cm/s) with carbon-based materials, designed for the first wall of a future thermonuclear reactor of the ICF or MCF type. Particular attention was paid to the verification of diagnostic techniques, which might be used for time-and space-resolved studies of the interaction of ion-and plasma-streams with the targets placed near the cathode outlet inside the experimental device.

The interdiffusion and the Kirkendall effect in the Co-Ni, Fe-Ni, and Fe-Co systems were studied at 1100°C. The compositional dependence of the interdiffusion coefficient was investigated in the whole composition range using the Matano-Boltzmann technique. The compositional dependences of diffusion coefficients of components were determined in the whole composition range using literature data on self-diffusion and heterodiffusion in these metals together with the values of the interdiffusion coefficients obtained in this work by the extrapolation of the compositional dependences of interdiffusion coefficients. The data obtained are discussed on the basis of both literature data on the diffusion of radioactive tracers in the alloys and the Kirkendall shift determined in the present work.