| Abstract Scope |
As fusion energy systems advance toward continuous operation, effective tritium permeation barriers (TPBs) are important to managing tritium inventory, reducing environmental release, and ensuring structural integrity. This study presents the design and characterization of a scalable, multilayer TPB architecture composed of alternating Cr and Al2O3 layers with Y2O3 top layer deposited via physical vapor deposition (PVD) and atomic layer deposition (ALD). The Cr/Al2O3/Y2O3 structure leverages ceramic/metal interfaces to suppress tritium transport while preserving mechanical and thermal stability under extreme environments typical of fusion breeding blankets (BB).
We investigate the barrier’s microstructural resilience, hydrogen permeability, and mechanical performance under thermal cycling and irradiation. The multilayers exhibit crack arrest behavior, and strong interfacial adhesion, following 650 °C thermal cycling and indentation testing. To probe radiation damage effects, proton irradiation experiments are performed at 300-350 keV (R.T.) to implant H+ directly within the metal and ceramic layers to understand its permeability through the layer at BB operating temperatures. 32.5 MeV Fe+ (600 °C) is used to simulate ~10 dpa damage followed by 72 h thermal cycling exposure and hydrogen permeation analysis. Complementary exposure to Sn-17Li at 550 °C for 2 weeks examine compatibility of irradiated and non-irradiated Y2O3.
These findings will inform the development of multifunctional, radiation-tolerant coatings that meet DEMO blanket requirements, including high PRF, radiation resistance, scalability, and performance under exposure to corrosive environment, enabling efficient tritium handling in future fusion reactors. |