Energy penetration into arrays of aligned nanowires irradiated with relativistic intensities: Scaling to terabar pressures.
Energy penetration into arrays of aligned nanowires irradiated with relativistic intensities: Scaling to terabar pressures.
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DOI：
10.1126/sciadv.1601558
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发表时间：
2017-01
期刊：
影响因子：
13.6
通讯作者：
Rocca JJ
中科院分区：
文献类型：
--
作者：
Bargsten C;Hollinger R;Capeluto MG;Kaymak V;Pukhov A;Wang S;Rockwood A;Wang Y;Keiss D;Tommasini R;London R;Park J;Busquet M;Klapisch M;Shlyaptsev VN;Rocca JJ
由相对论强度的激光脉冲加热的纳米线阵列开辟了通往极端能量密度和压力的道路。超高能量密度 (UHED) 物质的特征是能量密度 >1 × 108 J cm−3 和压力大于千兆巴，在恒星中心和由世界上最大的激光器驱动的惯性约束聚变舱中遇到。通过将相对论强度聚焦到由对齐的纳米线阵列组成的目标上的紧凑型、超高对比度、飞秒激光器可以获得类似的条件。我们报告了确定高纵横比纳米线阵列等离子体中沉积的能量密度的关键物理过程的测量：能量穿透。通过监测以 4 × 1019 W cm−2 强度照射的 Ni 纳米线阵列中埋藏 Co 示踪剂段的 X 射线发射，我们证明了几微米的能量穿透深度，从而产生了该尺寸的 UHED 等离子体。通过这些测量验证的相对论三维颗粒细胞模拟预测，以 >1 × 1022 W cm−2 的强度照射纳米结构将导致几乎未探索的极端 UHED 等离子体状态，其特征是能量密度超过 8 × 1010 J cm−3，相当于 0.35 Tbar 的压力。
Nanowire arrays heated by laser pulses of relativistic intensity open a path to extreme energy densities and pressures. Ultrahigh-energy density (UHED) matter, characterized by energy densities >1 × 108 J cm−3 and pressures greater than a gigabar, is encountered in the center of stars and inertial confinement fusion capsules driven by the world’s largest lasers. Similar conditions can be obtained with compact, ultrahigh contrast, femtosecond lasers focused to relativistic intensities onto targets composed of aligned nanowire arrays. We report the measurement of the key physical process in determining the energy density deposited in high-aspect-ratio nanowire array plasmas: the energy penetration. By monitoring the x-ray emission from buried Co tracer segments in Ni nanowire arrays irradiated at an intensity of 4 × 1019 W cm−2, we demonstrate energy penetration depths of several micrometers, leading to UHED plasmas of that size. Relativistic three-dimensional particle-in-cell simulations, validated by these measurements, predict that irradiation of nanostructures at intensities of >1 × 1022 W cm−2 will lead to a virtually unexplored extreme UHED plasma regime characterized by energy densities in excess of 8 × 1010 J cm−3, equivalent to a pressure of 0.35 Tbar.