Особенности внутренней структуры токовых слоев в бесстолкновительной плазме в присутствии шировой компоненты магнитного поля
The behaviour and erosion of tungsten, copper and W-Cu composition under irradiation by high intensive hydrogen plasma have been investigated. The erosion coefficients of these materials have been determined. The importance of copper redepositions in the mechanism of sputtering and erosion of W-Cu composition has been emphasised.
The method of elasstic recoils detection of deutrons and protons (ERDA) was used for the study of the accumulation and redistribution of hydrogen and deuterium atoms under the action of high-temperature deuterium plasma using of the "Plasma Focus" (PF-4) in an assembly of two Ni, Ti and Zr foils of high purity. It was found that when exposed to pulsed high-temperature plasma is a redistribution of the implanted deuterium and hydrogen gas impurities to great depths in the assemblies of the studied foils, considerably exceeding the ranges of deuterium ions (at their maximum speeds of up to 108 cm /s).
As in earlier studies, the observed phenomenon can be explained by: a) removal of the implanted hydrogen under the influence of powerful shock waves formed in the metal foil by pulsed deuterium plasma, and (or) the acceleration of the diffusion of hydrogen atoms under the influence of compression-dilatation waves in the front of a shock wave to the redistribution of hydrogen to great depths. A similar behavior is found in assemblies of two or three or more foils of nickel, vanadium, niobium, tantalum, different thicknesses, including assembly and foils of different materials, which have been well studied.
The geographical and seasonal distributions of kinematic and nonlinear parametersof long internal waves obtained on a base of GDEM climatology in the Baltic Sea region are examined. The considered parameters (phase speed of long internal wave, dispersion, quadratic and cubicnonlinearity parameters) of the weakly-nonlinear Korteweg-de Vries-type models (in particular, Gardner model), can be used for evaluations of the possible polarities, shapes of solitary internal waves, their limiting amplitudes and propagation speeds. The key outcome is an express estimate of the expected internal wave parameters for different regions of the Baltic Sea. The central kinematic characteristic is the near-bottom velocity in internal waves in areas where the density jump layers are located in the vicinity of seabed. In such areas internal waves are the major driver of sediment resuspension and erosion processes and may be also responsible for destroying the laminated structure of sedimentation regime (that frequently occurs in certain areas of the Baltic Sea).
Assemblies of Ta|CD2| Ta|Ta |CD2|Ta|Ta and Nb|CD2|Nb foils were irradiated 30th pulses of high-argon plasma on the "Plasma Focus" (PF-4). After irradiation, all samples foils were investigated by the elastic scattering of the recoil nuclei of hydrogen and deuterium (ERDA) on both sides. It found redistribution of hydrogen and deuterium in stacks of foils. Experimental results for lung penetration ultradeep gaseous impurities: hydrogen and deuterium are explained based on the effects of shock waves on the foils and accelerated diffusion induced by an external force.
The sputtering of a number of materials due to an intense polyenergetic flux of hydrogen particles has been investigated. The irradiation of pure tungsten, copper, aluminium, titanium, aluminium-lithium alloys, stainless steel and tungsten-copper composition has been carried out at particle flux densities of 1017-1018 cm~2 s~' and at fluences of 1020-1022 cm~2. Furthermore, W-Cu composition has been subjected to the effect of high-current plasma pulses for simulating the disruption heat loads in a thermonuclear reactor.