Density-dependent shock Hugoniot of polycrystalline diamond at pressures relevant to ICF

作者：Peng Wang, Chen Zhang, Shaoen Jiang, Xiaoxi Duan, Huan Zhang, Liling Li, Weiming Yang, Yonggang Liu, Yulong Li, Liang Sun, Hao Liu, Zhebin Wang · 发表于：Matter and Radiation at Extremes · 年份：2021 · DOI：10.1063/5.0039062 · 被引用次数：23 · 研究领域：Laser-Plasma Interactions and Diagnostics、Diamond and Carbon-based Materials Research、High-pressure geophysics and materials

In inertial confinement fusion (ICF), polycrystalline diamond—referred to as high density carbon (HDC)—has become a promising ablator candidate. However, with smaller grain size and lower initial density, the equation of state (EOS) for HDC can deviate from that for single-crystal diamond, which could be a concern for ICF designs, but current experimental EOS studies for HDC are far from sufficient to clarify how initial density affects target compressibility. Presented here are measurements of the Hugoniot for HDC with an initial density of 3.23 g/cm3 at pressures of 17–26 Mbar. Combined with experimental data reported for nanocrystalline diamond (NCD), a stiffer compressibility of NCD due to lower initial density is confirmed. Two porous models are used for comparison and seem to offer better agreement compared with SESAME databases. Also, the effect of temperature on the Grüneisen parameter, which is usually neglected, might need to be considered for NCD under these conditions. The present data offer important support for EOS studies relevant to ICF and constrain the construction of wide-range EOS.