An expansion model of hypervelocity impact-generated plasma aided by spectral methods

Space debris and meteoroids are proved to have serious mechanical and electromagnetic coupling damage effects on the safety of spacecraft. The co-existence of electromagnetic radiation from solid debris and plasma during hypervelocity impact (HVI) requires the elimination of the effects of the charged debris. Non-contact spectroscopic measurements are an optimal choice for obtaining characteristic parameters of the initial plasma while minimizing these effects. An evaluation method based on the radiant intensity and full width at half maximum (FWHM) of the spectral lines produced by HVI has been proposed for the first time for determining the average electron temperature and density of the plasma. By considering free electron oscillation in the vicinity of the ions, we develop a space-time expansion model for the HVI-generated plasma. The applicability of this theoretical model is validated by Langmuir tri-probe experiments. Our results demonstrate that the impact velocity plays a significant role in determining the plasma electron density and temperature, in comparison to the target plate thickness. Additionally, the numerical analysis is conducted to examine the effects of impact velocities on the plasma expansion kinematic characteristics. The electron density of plasma exhibits a vibrational decay with increasing time and distance, from 10¹³∼10¹⁴ to 10⁸∼10⁹ magnitudes, which is consistent with experimental measurements.