Statistical Analysis and Solid-Density Plasma Diagnosis with the Ti Lyα Resonance Line*

High-intensity lasers produce dense, transient plasmas, where conditions are relevant to inertial confinement fusion and plasma astrophysics. We study these extreme states by focusing lasers on solid targets with microstructure tracer layer of titanium covered in varying amounts of aluminum, which emit x-rays that are captured by high resolution x-ray spectrometers. Recent LaserNetUS experiments at the ALEPH facility utilized high repetition rates to produce a large dataset of high-resolution x-ray spectra from hundreds of shots per target type. Statistical variations in the spectra represent shot-to-shot variations in plasma parameters, such as ion and electron temperature. Conducting large-scale statistical analysis allows us to connect trends across many spectra to plasma conditions at high energy densities and can imply spatial dependence of plasma parameters. Here we study the 2s→1s shoulder of the Ti Lyα resonance line which indicates that plasma densities are near solid (10²⁴ electrons/cm³). By identifying hallmark features of Stark-broadening, we are able to extract plasma densities and temperatures.