A two-level model for K-shell radiation scaling of the imploding Z-pinch plasma radiation source

A simple, first-principle treatment is presented for estimating, within about a factor-of-two, how K-shell X-radiation from the plasma radiation source scales with plasma, pulsed-power, and imploding-load parameters. The transparency of this two-level model clarifies the relations between X-ray yield and underlying physical processes, provides simple analytic expressions for optimal load parameters and associated yields, and establishes links between radiating-load performance and system constraints imposed by other processes. The two-level model provides results similar to another one-zone model based on phenomenological extrapolations of selected one-dimensional radiation-hydrodynamic calculations. The model compares well with K-shell radiation results from Hawk neon gas puff and Saturn aluminum large-wire-number array experiments, provided that assumed compression ratios are less than those inferred from X-ray pinhole images. The reduced compression ratios required by the model can be traced to its one-zone nature.