Composition and Optical Properties of Warm Dense Germanium Plasma

A major effect of high-intensity, cold X-rays (1.0-1.5 keV) released from a high-altitude nuclear burst to a few microns of satellite surface materials is the absorption of X-rays, shock wave induction, blow-off, and generation of warm dense plasma (WDP). It produces the extreme pressures and temperatures causing the damage of exposed optics, sensors, and solar cells on satellites. Implications of X-ray irradiation of solar cells are potentially quite serious. The semiconductor elements are not shielded and can be directly exposed to X-ray radiation when a solar panel is oriented under some angle relative to the X-ray source. The dense surface plasmas can couple the solar cells to each other and to dielectric structures, particularly in a gap between the unshielded Germanium (Ge) elements causing them to be destroyed. The study and understanding the physical and electrical properties of WDP generated in the cold X-ray radiation environment can improve the ways to design more survivable solar arrays for satellites. High-fidelity computational models are vital to guide our fundamental understanding of the underlining physics of WDP and its physical properties.