Williamson K M, Kantsyrev V L, Safronova A S, Wilcox P G, Cline W, Batie S, LeGalloudec B, Nalajala V, Astanovitsky A
Plasma Physics and Diagnostics Laboratory, Physics Department, University of Nevada, Reno, Nevada 89557, USA.
Rev Sci Instrum. 2011 Sep;82(9):093506. doi: 10.1063/1.3626930.
This recently developed diagnostic was designed to allow for time-gated spectroscopic study of the EUV radiation (4 nm < λ < 15 nm) present during harsh wire array z-pinch implosions. The spectrometer utilizes a 25 μm slit, an array of 3 spherical blazed gratings at grazing incidence, and a microchannel plate (MCP) detector placed in an off-Rowland position. Each grating is positioned such that its diffracted radiation is cast over two of the six total independently timed frames of the MCP. The off-Rowland configuration allows for a much greater spectral density on the imaging plate but only focuses at one wavelength per grating. The focal wavelengths are chosen for their diagnostic significance. Testing was conducted at the Zebra pulsed-power generator (1 MA, 100 ns risetime) at the University of Nevada, Reno on a series of wire array z-pinch loads. Within this harsh z-pinch environment, radiation yields routinely exceed 20 kJ in the EUV and soft x-ray. There are also strong mechanical shocks, high velocity debris, sudden vacuum changes during operation, energic ion beams, and hard x-ray radiation in excess of 50 keV. The spectra obtained from the precursor plasma of an Al double planar wire array contained lines of Al IX and AlX ions indicating a temperature near 60 eV during precursor formation. Detailed results will be presented showing the fielding specifications and the techniques used to extract important plasma parameters using this spectrometer.
这种最近开发的诊断设备旨在对强电流丝阵Z箍缩内爆期间存在的极紫外辐射（4纳米＜λ＜15纳米）进行时间选通光谱研究。该光谱仪采用一条25微米宽的狭缝、一组3个掠入射球面闪耀光栅以及一个置于罗兰圆外位置的微通道板（MCP）探测器。每个光栅的位置设置为使其衍射辐射投射到MCP总共6个独立定时帧中的两帧上。罗兰圆外配置能使成像板上的光谱密度大大提高，但每个光栅仅聚焦于一个波长。选择这些聚焦波长是因其具有诊断意义。在内华达大学里诺分校的斑马脉冲功率发生器（1兆安，100纳秒上升时间）上，对一系列丝阵Z箍缩负载进行了测试。在这种强Z箍缩环境中，极紫外和软X射线波段的辐射产额通常超过20千焦。此外还有强烈的机械冲击、高速碎片、运行期间的突然真空变化、高能离子束以及超过50千电子伏的硬X射线辐射。从铝双平面丝阵的前驱等离子体获得的光谱中包含铝IX和铝X离子的谱线，这表明在前驱形成期间温度接近60电子伏。将展示详细结果，说明该光谱仪的现场使用规格以及用于提取重要等离子体参数的技术。
