Shock-wave experiment with the Chelyabinsk LL5 meteorite: experimental parameters and the texture of the shock-affected material)

The shock experiment with Chelyabinsk LL5 light lithology material was performed as a spherical geometry shock. The material experienced shock and thermal metamorphism from the initial S3–4 up to complete melt stage. Temperature and pressure realized were estimated above 2000°С and 90 GPa. Textural shock effects were studied by the means of optical and electron microscopy. By the only experimental impact, all the range of the shock pressures and temperatures was realized. Four zones were revealed from the petrographic analysis: 1 – melt zone, 2 – melted silicates zone, 3 – black ring zone, 4 – weakly shocked initial material. Several features of the material texture were noted: displacement of the metal and troilite phases from the central melt zone; mixed lithology zone formation (light-colored chondrules within the silicate melt); dark-colored lithology ring formation; generation of radial-oriented shock veins. Thus, at the experimental fragment, four texture zones were formed. These zones correspond to the different lithology types of the Chelyabinsk LL5 meteorite, which could be found in different fragments of the meteoritic shower from UrFU collection. The results obtained prove that the shock wave loading experiment could be used for space shock modeling. Therefore, the processes of the small bodies of the Solar system could be experimentally modeled at the laboratory conditions.

Approaching the “cold curve” in laser-driven shock wave experiment of a matter precompressed by a partially perforated diamond anvil

This paper suggests a novel route to approach the cold compression curve in laser-plasma induced shock waves. This effect is achieved with a precompression in a diamond anvil cell (DAC). In order to keep the necessary structure of one dimensional shock wave it is required to use a diamond anvil cell with a partially perforated diamond anvil. Precompression pressures of about 50 GPa, that are an order of magnitude higher than the currently reported pressures, are possible to obtain with presentley existing diamond anvil cell technology. The precompressed Hugoniot of Al was calculated for different precompression pressures and it was found that at precompression pressure of 50 GPa the Hugoniot follows the “cold curve” up to about 2 Mbar and 5.2 g/cc. Furthermore, the thermal relative contribution on the Hugoniot curves is calculated.