Effect of Tungsten Shielding with Bismuth under the Influence of Powerful Flow of Hydrogen Plasma

The results of investigation of the effect of powerful hydrogen plasma flow created by the 2MK-200 pulsed accelerator on a layer of bismuth 7.5 µm thick previously vacuum-sprayed onto a 30 × 30 × 3 mm tungsten plate are presented. At an energy density of the plasma flow at the level of ≈600 J/cm2 with a duration of ≈15 μs, the target with bismuth, owing to the shielding effect, absorbed ≈12 J/cm2. On the frontal surface of bismuth, the temperature measured by a spectral pyrometer did not exceed ≈1900 K during the entire exposure to hydrogen plasma. The spectroscopy data of near-surface plasma radiation are presented, according to which the radiation of bismuth plasma in the spectral range ∆λ ≈ 2–20 nm is localized near the surface at a distance of ≤4–6 cm. The rate of bismuth evaporation per exposure at the specified plasma flow parameters was ≈0.5 µm in thickness.