Damage of Al2O3 ceramics under the action of pulsed ion and plasma fluxes and laser irradiation

Abstract

The effects of powerful pulsed ion and high-temperature plasma fluxes generated in a plasma focus (PF) device and the effect of free running laser radiation on a corundum (α-Al₂O₃) ceramic produced by powder technology are studied. The power flux density q and acting pulse time τ for plasma stream, ion flux, and laser irradiation were q_p ≈ 10⁷ W/cm² and τ_p ≈ 100 ns, q_i ≈ 10⁸ W/cm² and τ_i ≈ 20 ns, and q_l ≈ (3–5) × 10⁵ W/cm² and τ_l ≈ 0.7 ms, respectively. The resistance of the ceramic to pulsed energy fluxes was estimated by the weight loss of irradiated specimens and by the surface layer defects (damage). The combined use of PF and pulsed laser irradiation is shown to allow simulation of the extreme erosion and damage of materials in thermonuclear fusion facilities (such as ELM effects in ITER or at the first wall of inertial confinement chambers).