Isentropic expansion of copper plasma in Mbar pressure range at “Luch” laser facility

Abstract

We present experimental results on thermodynamic properties of dense copper plasma in Mbar pressure range. The laser facility “Luch” with laser intensity 1014 W/cm2 is used to compress copper up to ∼8 Mbar by a strong shock wave; subsequent expansion of copper plasma into Al, Ti, Sn allows us to obtain release isentropes of copper by the impedance–matching method. A theoretical analysis and quantum simulations show that in our experiments strongly coupled quantum plasma is generated.

Powerful Lasers for High Energy Density Physics

“…Another direction of works on the "Luch" setup is studies on the compressibility of materials (more than 100 such experiments are performed every year). The shock and shockless compressibility and unloading of a broad spectrum of materials (condensed, porous, optically transparent) are estimated [31]. New target designs were developed to enable researchers to move to the multimegabar range of pressures (up to 100 Mbar).…”

High- and low-entropy layers in solids behind shock and ramp compression waves

“…Dynamic loading of thin metallic foils is under increasing attention [1][2][3][4][5][6][7][8][9] because it is the way to investigate the matter properties at extremely high strain rates. Plate impact is used for foils perhaps no thinner than 20 µm, [1][2][3] while the ultra-short intensive laser irradiation [4][5][6][7][8][9] can be used for foils of several microns in thickness or even thinner; the strain rate exceeds 10 9 s −1 in the latter case.…”

“…Dynamic loading of thin metallic foils is under increasing attention [1][2][3][4][5][6][7][8][9] because it is the way to investigate the matter properties at extremely high strain rates. Plate impact is used for foils perhaps no thinner than 20 µm, [1][2][3] while the ultra-short intensive laser irradiation [4][5][6][7][8][9] can be used for foils of several microns in thickness or even thinner; the strain rate exceeds 10 9 s −1 in the latter case. Dynamic shear strength and spall strength tend to the theoretical limits at such extreme loading conditions; 4,7,10 these strengths are determined by inertness of development of the defects subsystems-dislocations and voids correspondingly.…”

“…Meanwhile, those are essential for thin foils, such as used in experiments. [1][2][3][4][5][6][7][8][9] Therefore, formation of the nonisentropic layers should be investigated for adequate analysis of the experimental results.…”