Modification of the composite multi-layer oxide ceramic coating on meteoroid shielding element by compression plasma flow

The aim of this work is investigation of the influence of high-energy plasma impact on composite multi-layer coating (NiAl as a sublayer and Al₂O₃ as a top coat) on meteoroid shielding element. In order to reach this goal qausi-stationary plasma accelerator with impulse gas feeding was used. Experiments were conducted with use of helium and hydrogen gas mixture and nitrogen as plasma forming substance. Plasma accelerator generates plasma jet with electron temperature ≈ 150 kK and electron density (2.5-4) × 10¹⁶ cm^-3. Visual examination, photography and spectral measurements were made through special vacuum chamber optical windows. (paper)