On the effect of conductivity of a shock-compressed gas on interferometric recording of parameters of motion of a liner

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.     

Ejection of Particles from the Free Surface of Shock-Loaded Lead into Vacuum and Gas Medium

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.     

Erratum to: Effect of Shock-wave Dusting and Ways to Suppress It

Journal of Experimental and Theoretical Physics - An Erratum to this paper has been published: https://doi.org/10.1134/S106377612230001X     

Experimental-calculation simulation of the ejection of particles from a shock-loaded surface

The possibilities of measuring complex Pylenie, which is intended for studying the parameters of the particles ejected from the free surface of a shock-loaded material and was created at the Institute of Experimental Gas Dynamics and Detonation Physics RFNC-VNIIEF, are demonstrated. The operation of the complex is based on the following three methods, which are based on different physical principles and supplement each other: laser-optical method (macro- and microfilming), pulsed X-ray method, and piezoelectric pressure sensors. This complex is used to study the ejection of particles from the free surface of lead samples when a shock wave with a pressure of 7, 16, and 23 GPa at its front reaches this surface. The effect of the surface roughness and the pressure amplitude at the shock wave front on the quantitative characteristics of the process is shown. The calculation-theoretical simulation is performed by two-dimensional numerical calculations of gasdynamic flows, and the calculation results are used to estimate the “ejecta” characteristics in terms of the developed phenomenological model of the process.     

Quasi-Isentropic Compression of a Nonideal Plasma of Deuterium and its Mixture with Helium at Pressures up to 250 GPa

Journal of Experimental and Theoretical Physics - We present data on the quasi-isentropic compressibility of a strongly coupled (nonideal) plasma of a deuterium–helium mixture in the range of...     

Compressibility of Nonideal Deuterium and Helium Plasmas up to 20 TPa

Journal of Experimental and Theoretical Physics - We present our experimental results on the compressibility of strongly coupled (nonideal) degenerate deuterium and helium plasmas...     

Effect of Shock-Wave Dusting and Ways to Suppress It

Journal of Experimental and Theoretical Physics - The ejection of particles from the free surface of metal liners accelerated to velocities of 4–5 km/s using explosive energy has been...     

Detecting the ejection of particles from the free surface of a shock-loaded sample

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.     

Effect of shock–wave loading on the properties of cryogenic TiNi — a shape–memory alloy

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.     

Effect of a gas on the ejection of particles from the free surface of a sample subjected to a shock wave with various intensities

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.