Quasi-isentropic compression of gaseous helium in pressure range from 130 to 460 GPa

Abstract

Abstract.Here we present the results for experiments of gaseous helium with an initial density of 0.019 g/cm 3 cylindrically compressed. The cylindrical compression technique transforms shock compression to quasi-isentropic compressions. The resulting pressures attained were from 130 to 460 GPa with compressed densities of 1.3 to 2.3 g/cm 3 for a compression ratio ( 0 δ = ρ ρ ) from 70 to 115.The density of the gas was determined from X-ray radiography based on the boundary location of the steel liners, which compressed the gas. The pressures Gas density was determined by the X-ray radiography method basing on location of boundaries of the steel shells, which compressed gas. Pressures were based upon gas-dynamic calculations.