Shock-Wave Compression of Nitrogen Fluid in the Pressure Range 140-250 GPa

The results of a series of experiments on the shock compression of a dense nitrogen fluid, which is preliminarily statically compressed to an initial density rho = 0.8, 0.65, and 0.5 g/cm(3), to pressures of 140-230 GPa in hemispherical shock-wave generators are discussed. The experiments are carried out in continuation and development of the earlier series of experiments on the shock compression of liquid nitrogen to pressures of 100-330 GPa, which were performed at VNIIEF (Sarov) in 2008-2010. The purpose of our experiments is to verify and confirm the earlier revealed limiting compression of nitrogen to a limit close to an ideal gas (rho/rho(0) approximate to 4.2) and the remarkable subsequent quasi-isochoric segment of the Hugoniot adiabat in the pressure range 100-330 GPa. The experimental data obtained are compared with the results of theoretical calculations performed with various models of the equation of state of a nonideal nitrogen plasma.