Ta–V Nanoscale Multilayered Hydrogen Diffusion Layers for High‑Power Boron Neutron Capture Therapy Neutron Targets: Microstructure, Hydrogen Embrittlement Resistance, and Irradiation Performance

Boron neutron capture therapy (BNCT) requires high‐performance neutron source targets for stable operation. Single target materials struggle to simultaneously satisfy high neutron yield, hydrogen embrittlement resistance and effective thermal management, restricting high‐power, long‐lifetime BNCT systems. Ta–V nanolayered multilayers, fabricated via pulsed DC magnetron sputtering, serve as hydrogen diffusion interlayers for BNCT lithium targets. Sputtering power and substrate bias govern film characteristics and irradiation response, characterized by scanning electron microscope, X‐ray diffractometer, X‐ray photoelectron spectroscopy, transmission electron microscopy alongside SRIM and PHITS simulations. These multilayers form dense, uniform coatings with strong interfacial adhesion to copper substrates. Raised Ta sputtering power drives the phase transition from metastable β‐Ta to stable α‐Ta and enhances crystallinity, while −120 V substrate bias balances residual stress, surface morphology and crystal structure. The Ta–V nanostructure integrates the complementary hydrogen‐related properties of Ta and V and suppresses irradiation‐induced blistering. SRIM results demonstrate that alternating Ta–V layers disperse proton energy deposition, mitigate radiation damage and reduce proton penetration depth. Optimized Ta–V nanolaminates are promising interlayers for BNCT lithium targets.