Evaluation of X-ray Spectroscopic Techniques for Determining Temperature and Density in Plasmas

Role of Simple Spatial Gradient in Reinforcing the Accuracy of Temperature Determination of HED Plasma via Spectral Line-Area Ratios

“…The experiments were performed on the Z Facility at SNL [12], using the Z Pinch Dynamic Hohlraum (ZPDH) [13], under the auspices of the Z Astrophysical Plasma Properties (ZAPP) collaboration [14]. As the materials and methods have been documented elsewhere [9,10], we provide only a summary of the experimental scenario. In particular, the ZPDH consists of a 120 tungsten wire array with an inner diameter of 20 mm, nested in a 240 tungsten wire, 40 mm diameter array [14].…”

“…A cylindrical, 6 mm diameter, 14.5 mg/cm 3 CH 2 foam fits in the center of the inner array [15]. Current in excess of 26 MA, provided by discharging 36 Marx capacitor banks in parallel [16], flows through the wire arrays over a 100 ns interval, with peak current lasting approximately 3 ns [10]. Driven by the J × B force, ablated tungsten streams towards the z-pinch axis until stagnation, driving a radiating shock through the foam [15].…”

“…In this study, we implement the collisional-radiative model PRISMSPECT [8] to construct synthetic absorption spectra, which are subsequently compared with data gathered from the Z Facility at SNL. In line with previous work that utilized line-area ratios to infer electron temperature in a radiatively-heated NaFMgO plasma [9,10], we investigate the robustness of line-area ratios in the presence of spatial gradients.…”

“…However, because this may be an artifact of a time-varying temperature, we are motivated to perform the more careful analysis herein. To best reproduce the experimental conditions, we demand that the total length L ≡ L 1 + L 2 conforms to the measured size of the NaFMgO layer, thus L = 3494 Å [10].…”

“…Effectively, this report is an extension of line-ratio techniques documented in refs. [9][10][11] and elsewhere. Section 2 outlines the experimental set-up, while Section 3 details our hypothesis and various methods of data reduction.…”