High-density compression experiments at ILE, Osaka
High-density compression experiments at ILE, Osaka
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大阪 ILE 的高密度压缩实验
DOI：
10.1017/s0263034600003281
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发表时间：
1991
影响因子：
0.9
通讯作者：
C. Yamanaka
中科院分区：
文献类型：
--
作者：
H. Azechi;T. Jitsuno;T. Kanabe;M. Katayama;K. Mima;N. Miyanaga;M. Nakai;S. Nakai;H. Nakaishi;M. Nakatsuka;A. Nishiguchi;P. A. Norrays;Y. Setsuhara;M. Takagi;M. Yamanaka;C. Yamanaka
壁虎XII激光器(9 kJ，0.5μm，2 ns)与氘、氚(DT)交换的塑料中空壳靶的直接驱动内爆实验表明，在燃料温度为˜0.3keV时，燃料面密度(˜R)为0.1g/cm~2，燃料密度为˜液体密度的600倍。(Density和ρR值仅指DT，不包括塑料目标中的碳。)这些值将与热核点火条件进行比较，即燃料密度为液体密度的500-1000倍，燃料面密度大于0.3g/cm2，燃料温度大于5keV。通过引入随机位相板，这些实验中的辐照不均匀性显著降低到均方根值的5%。靶区不规则性控制在1%的水平。燃料ρ-R是用塑料靶材中最初复合的硅的中子活化直接测量的。使用质量守恒关系从ρR值估计燃料密度，其中烧蚀质量是使用多层靶随时间变化的X射线发射单独测量的。虽然在收敛比为25-30的情况下，观测密度与一维计算结果一致，但观测到的中子产额明显低于计算值。这表明，内爆的均匀性不足以产生大多数中子应该产生的热火花。
Direct-drive implosion experiments on the GEKKO XII laser (9 kJ, 0.5 μm, 2 ns) with deuterium and tritium (DT) exchanged plastic hollow shell targets demonstrated fuel areal densities (ρR) of ˜0.1 g/cm2 and fuel densities of ˜600 times liquid density at fuel temperatures of ˜0.3 keV. (The density and ρR values refer only to DT and do not include carbons in the plastic targets.) These values are to be compared with thermonuclear ignition conditions, i.e., fuel densities of 500–1000 times liquid density, fuel areal densities greater than 0.3 g/cm2, and fuel temperatures greater than 5 keV. The irradiation nonuniformity in these experiments was significantly reduced to a level of <5% in root mean square by introducing random-phase plates. The target irregularity was controlled to a 1% level. The fuel ρR was directly measured with the neutron activation of Si, which was originally compounded in the plastic targets. The fuel densities were estimated from the ρR values using the mass conservation relation, where the ablated mass was separately measured using the time-dependent X-ray emission from multilayer targets. Although the observed densities were in agreement with one-dimensional calculation results with convergence ratios of 25–30, the observed neutron yields were significantly lower than those of the calculations. This suggests the implosion uniformity is not sufficient to create a hot spark in which most neutrons should be generated.