Diagnostic application of Kr K-Shell x-ray tracer spectroscopy in MagLIF experiments at Z

In a series of MagLIF experiments performed at the Z pulsed power facility of Sandia National Laboratories beryllium liners filled with deuterium gas densities in the 0.7 to 1.4 mg/cc range, and a tracer amount of krypton were imploded. At the collapse of the cylindrical implosion temperatures in the 1 – 3 keV range and atom number densities of ∼10²³ cm⁻³ were expected. The plasma was magnetized with a 10 T axial magnetic field. Krypton K-shell line emission was recorded with the CRITR time-integrated transmission crystal x-ray spectrometer. The observation shows n=2-1 line emissions in B-, Be, Li- and He-like Kr ions, and is characteristic of the highest electron temperatures achieved in the thermonuclear plasma. Detailed modeling of the observation based on krypton atomic and radiation physics demonstrates that the spectrum is temperature dependent. Since the observation is time-integrated, we perform the analysis with single- and multi-temperature models. We will discuss the limitations of single-temperature results, as well as the characteristics of extended analysis performed with two-temperature models.