Probing near-solid density plasmas using soft x-ray scattering
Probing near-solid density plasmas using soft x-ray scattering
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DOI：
10.1088/0953-4075/43/19/194017
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发表时间：
2010-10-14
影响因子：
1.6
通讯作者：
Tschentscher, T.
中科院分区：
文献类型：
--
作者：
Toleikis, S.;Bornath, T.;Tschentscher, T.
利用高亮度X射线自由电子激光（FEL）辐射的X射线散射为探测近固体密度等离子体中的自由电子密度、温度和电离提供了新的途径。第一个实验在软X射线自由电子激光FLASH在DESY，汉堡，显示这种技术的能力。超短自由电子激光脉冲特别可以探测使用超短光学激光泵浦激发等离子体后发生的平衡现象。我们已经调查了液态氢，发现非常强烈的软X射线自由电子激光辐射的相互作用单独加热样品体积。随着等离子体的建立，来自同一脉冲的光子经历散射，从而探测瞬态的、温暖的致密物质状态。我们发现自由电子密度为（2.6 +/- 0.2）× 10（20）cm（-3），电子温度为14 +/- 3.5 eV。在泵浦探测实验中，使用强激光脉冲来产生更极端的物质状态，在解释散射数据时必须考虑探测脉冲的这种相互作用。在本文中，我们提出了详细的实验设置在FLASH和诊断方法，用于定量分析的数据。
X-ray scattering using highly brilliant x-ray free-electron laser (FEL) radiation provides new access to probe free-electron density, temperature and ionization in near-solid density plasmas. First experiments at the soft x-ray FEL FLASH at DESY, Hamburg, show the capabilities of this technique. The ultrashort FEL pulses in particular can probe equilibration phenomena occurring after excitation of the plasma using ultrashort optical laser pumping. We have investigated liquid hydrogen and find that the interaction of very intense soft x-ray FEL radiation alone heats the sample volume. As the plasma establishes, photons from the same pulse undergo scattering, thus probing the transient, warm dense matter state. We find a free-electron density of (2.6 +/- 0.2) x 10(20) cm(-3) and an electron temperature of 14 +/- 3.5 eV. In pump-probe experiments, using intense optical laser pulses to generate more extreme states of matter, this interaction of the probe pulse has to be considered in the interpretation of scattering data. In this paper, we present details of the experimental setup at FLASH and the diagnostic methods used to quantitatively analyse the data.