Opachich Y P, Dodd E S, Heeter R F, Harris C D, Johns H M, Kline J L, Krasheninnikova N S, May M J, Moore A S, Rubery M S, Schneider M B, Urbatsch T J, Widmann K, Perry T S
Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Rev Sci Instrum. 2021 Mar 1;92(3):033519. doi: 10.1063/5.0040972.
The Opacity Platform on the National Ignition Facility (NIF) has been developed to measure iron opacities at varying densities and temperatures relevant to the solar interior and to verify recent experimental results obtained at the Sandia Z-machine, that diverge from theory. The first set of NIF experiments collected iron opacity data at ∼150 eV to 160 eV and an electron density of ∼7 × 10 cm, with a goal to study temperatures up to ∼210 eV, with electron densities of up to ∼3 × 10 cm. Among several techniques used to infer the temperature of the heated Fe sample, the absolutely calibrated DANTE-2 filtered diode array routinely provides measurements of the hohlraum conditions near the sample. However, the DANTE-2 temperatures are consistently low compared to pre-shot LASNEX simulations for a range of laser drive energies. We have re-evaluated the estimated uncertainty in the reported DANTE-2 temperatures and also the error generated by varying channel participation in the data analysis. An uncertainty of ±5% or better can be achieved with appropriate spectral coverage, channel participation, and metrology of the viewing slot.
国家点火装置（NIF）上的不透明度平台已被开发出来，用于测量与太阳内部相关的不同密度和温度下的铁不透明度，并验证桑迪亚Z机器最近获得的与理论相悖的实验结果。NIF的第一组实验在约150电子伏特至160电子伏特以及约7×10厘米的电子密度下收集了铁不透明度数据，目标是研究高达约210电子伏特、电子密度高达约3×10厘米的温度。在用于推断加热铁样品温度的几种技术中，经过绝对校准的DANTE - 2滤波二极管阵列通常会提供样品附近黑腔条件的测量值。然而，对于一系列激光驱动能量，与射击前的LASNEX模拟相比，DANTE - 2温度一直偏低。我们重新评估了报告的DANTE - 2温度的估计不确定性，以及数据分析中不同通道参与所产生的误差。通过适当的光谱覆盖、通道参与和视窗计量，可以实现±5%或更好的不确定性。
