Progress toward x-ray Thomson scattering of warm dense matter on the Z accelerator

• Published in: Journal of physics. Conference series 2014-01, Vol.500 (8), p.82001-6
• Main Authors: Ao, T, Harding, E C, Bailey, J E, Desjarlais, M P, Hansen, S B, Lemke, R W, Rochau, G A, Sinars, D B, Smith, I C, Geissel, M, Reneker, J, Kernaghan, M D, Mix, L P, Wenger, D F
• Format: Article
• Language: English
• Subjects: Accelerators; Foams; Lasers; Manganese; Metal foils; Physics; Spectral resolution; Spectrometers; Thomson scattering; Wavelength division multiplexing; X ray sources; X-ray scattering; X-rays
• ISSN: 1742-6596; 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/500/8/082001

Experiments on the Z accelerator have demonstrated the ability to produce warm dense matter (WDM) states with unprecedented uniformity, duration, and size. Significant progress to combine x-ray Thomson scattering (XRTS), a powerful diagnostic for WDM, with the unique environments created at Z has been accomplished. The large current of Z is used to magnetically launch Al flyers to impact CH2 foam (0.12 g/cm3) samples. The uniformly-shocked CH2 foam volume is about 10 mm3 and the steady shock state lasts up to about 100 ns, which are approximately 1000 & 100 times larger, respectively, than typical laser shocked samples. The Z-Beamlet laser irradiates a 5 μm thick Mn foil near the load to generate 6.181 keV Mn-He-α x-rays that penetrate into the CH2 foam and scatter from it. A high sensitivity x-ray scattering spherical spectrometer with both high spatial and spectral resolution is fielded, which enables benchmark quality data by simultaneously measuring x-rays scattered from shocked and ambient regions of the CH2 foam, and the Mn x-ray source. Experimental efforts have achieved low x-ray background and mitigation of load debris, and measured high quality XRTS data of ambient CH2 foam have validated the technique.