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We present data on the quasi-isentropic compressibility of a strongly coupled (nonideal) plasma of a deuterium–helium mixture in the range of pressures 150–250 GPa in devices with a cylindrical geometry and a new result obtained in an experiment with “pure” deuterium at a pressure ~200 GPa. The trajectory of the plasma-compressing metallic shells was recorded using powerful pulsed X-ray sources with a boundary electron energy up to 60 MeV. The densities of the plasma of deuterium and its mixture with helium were determined from the measured radii of the shells at the instant of their “stopping.” We derived the pressure of the compressed plasma based on gasdynamic computations including the real characteristics of the experimental devices. The data obtained confirm the conclusion previously reached at VNIIEF about a phase transition in the plasma of compressed deuterium in the range of pressures 150–160 GPa and suggest that this phase transition is retained in the mixture of deuterium with helium.

The results of experimental studies of the shock-induced particle ejection (“dusting”) from a free rough (Rz = 20) surface of lead and copper samples into an evacuated medium are presented. The experimental methods were based on different physical principles. To determine the size of particles by shadow laser-optical imaging more efficiently, a narrow strip was isolated in the center of the free surface of a sample from which an optically transparent stream of particles was ejected. The rest of the surface, substantially larger in size, ejected particles, parameters of which were reliably recorded using optical heterodyne interferometry detection, radiographic imaging, and piezoelectric techniques. This made it possible to obtain more reliable data on the particle size distribution, the velocity of the front of a particle flux, and the density (weight) distribution of the flow in the direction of its motion, necessary to refine the existing models and create more reliable models to describe the phenomenon. Using lead and copper samples, the material of which melts or does not melt under shock wave loading in selected close conditions (amplitude of the shock wave and roughness of the free surface), made it possible to clearly demonstrate the effect of melting on the qualitative pattern and quantitative characteristics of the shock-induced dusting process.

The presence and behavior of a gas–metal interfacial layer at the free surface of shock-wave driven flying vehicles in gases of various compositions and densities has not been sufficiently studied so far. We present new comparative data on “dusting” from the free surface of lead into vacuum and gas as dependent on the surface roughness, pressure amplitude at the shock-wave front, and phase state of the material. Methods of estimating the mass flux of ejected particles in the presence of a gas medium at the free metal surface are proposed.

We report experimental results on studies of the interactions between various gases and the mass ejected from a shock accelerated surface. While such studies have been conducted in the past, data on such dynamic gas-ejecta interactions are incomplete. Therefore, along these lines, in the present work new comparative results are given concerning mass ejection from free surfaces of lead interfaced with vacuum or gas. The comparisons are made for the ejecta mass as a function of the surface roughness, the peak shockwave loading stress (amplitude) $$P_S$$ , and the release phase (state) of the post-shock metal.

The influence of hydrogen on the strength and ductility of 30KhGSA and EI659 steels in quasi-static and shock-loading tests was studied experimentally. The sensitivity of the steels to hydrogenation in air under normal pressure or in hydrogen at a pressure of 25 MPa was determined from the results of tests of as-received and pre-hydrogenated samples at a temperature of 773 K and a hydrogen pressure of 50 MPa for 24 h. It is found that EI659 steel doped with tungsten and vanadium is less sensitive to hydrogenation than 30KhGSA steel doped with manganese and chromium.

In view of the possible effect of contamination of a plasma by metal particles on the operation of a number of facilities or on the detection of the motion of liners by Doppler methods, a particular attention has been recently focused on the problem of the ejection of particles from the shock-loaded free surface of a sample or on the “dusting” problem. Most information concerns the dusting source associated with the roughness of the surface, manufacturing technology, and the defectiveness and aging of a material. Factors affecting this process such as the profile and amplitude of the pressure on the front of the shock wave arriving at the free surface of the sample, the presence of the gas in front of the free surface, and the pressure in this gas are less studied.

We report on the results of a study of the acceleration dynamics of an aluminum liner to a velocity of 5.5 km/s using continuous recording of velocity (velocity interferometer system for any reflector (VISAR) and Fabry-Perot interferometer) and motion trajectory (radiointerferometer and resistive transducer) in air and in a helium atmosphere. It is found that for liner velocities exceeding 4.0 and 5.0 km/s, the displacement of the shock wave front is recorded by the radiointerferometer in air and helium, respectively. At these velocities, the conductivities of air and helium behind the shock wave front are estimated.

The results of a medium-scale experiment in which a prototypical melt is produced by combustion of a chemically active substance in the course of the reaction 2Fe2O3 + 3Zr = 3ZrO2 + 4Fe + 2840 kJ/kg in a ~6·10−2 m3 concrete container are presented. It is shown that the ~100 kg melt, whose temperature is 2700–3200 K, so obtained produces heat fluxes 100–150 kW/m2 into the walls and bottom of the concrete container for ~10 min. The ablation of the walls of the concrete container was 2.5–3 cm at the completion of the experiment.

The details of the ejection of 20- to 200-µm particles with a velocity of 1.0-1.5 km/s from the surfaces of lead and steel samples with a roughness of 5-40 µm (Rz 5-Rz 40) when shock waves with an amplitude of 15 and 27 GPa reach them are visualized with a high-speed streak camera with a CCD matrix and pulsed laser illumination at a pulse duration of 4 ns. The size and velocity distributions of the particles are obtained.

Results of an experimental and numerical study of interaction of a metallic liner accelerated by an explosion to a velocity of several kilometers per second with lumped elements in the form of plates are presented. Parameters of perturbations transferred over these elements are quantified.

The process of dynamic deformation of shock-loaded cylindrical “porous” samples of lead, tungsten, and the 95% W + 3.5% Ni + 1.5% Fe alloy consisting of particles 0.1–2.5 mm in size is considered. The shock-wave intensity was slightly lower than the values corresponding to complete compaction of the material. The influence of the particle size and material strength and plasticity on the processes considered is examined.

This paper reports results from a comparative experimental study of the dynamic strength of St. 20 and 09G2S steels (which are of interest as structural materials for the load‐bearing casings of explosion‐proof chambers) under shock compression and tension (spalling) at shock‐front pressures of 1–5 GPa and strain rates of 103 – 104 sec-1. A comparative analysis is performed of the obtained and available data on the dynamic yield point and spall strength of St. 3, St. 20, 09G2S, 12Kh18N10T, EI712, 30KhGSA, 36NKhTYu, KhVG, and 35Kh3NM steels and armco iron, whose strengths and ductilities under static loading conditions differ by a factor of up to five. Experiments are described in which spheres of St. 3, St. 20, 12Kh18N10T, and 30KhGSA steels with markedly different strengths and ductilities are loaded by a convergent quasispherical shock wave with a pressure at the center of 200 GPa and a strain rate of 105sec-1.

Results of an experimental study of the shock–wave deformation of TiNi and its effect on the crystallographic structure and temperature of austenite–martensite transformations are given. It is found that, for pressures of up to 2 GPa, shock–wave loading changes the defect structure and parameters of the lattice; however, this does not lead to a noticeable change in the temperature of the austenite–martensite transformation and the manifestation of the shapeNdash;memory effect.

The paper reports results from measurements of free‐surface velocity profiles of shock‐loaded zirconium dioxide ceramics with a porosity of 16–22% produced from compositions with a size of the coarse fraction of 0.5–2.0 mm. Shock‐wave loading of ZrO2 samples 5–20 mm thick was performed by aluminum impactors 3–12 mm thick with a velocity of 10–100 m/sec. The measured free‐surface velocity profiles were used to assess the dynamic compressive and tensile strengths of the ceramics and thedamping properties of the ceramics.

It is noted that interest has increased in refractory materials such as zirconium dioxide ceramic and concrete for use as linings of traps for the melt of a reactor core. The shock-wave profiles are investigated under dynamic conditions, the dynamic strength is determined, and comparative experiments are performed to investigate the spallation resistance of these materials. It is noted that damping properties of ceramic are manifested: this is the reason why ceramic is more resistant to spallation than concrete. 5 figures, 3 tables, and 14 references.