Nuclear Engineering ETDs

Publication Date

Spring 5-16-2026

Abstract

Nuclear fusion is a promising pathway for sustainable energy production, but the performance of plasma-facing materials remains a key challenge for reactor operation. In particular, hydrogen isotope retention in tungsten—the leading candidate material for divertor components—affects tritium inventory, fuel recycling, and overall material lifetime. In this work, the temperature-dependent deuterium retention behavior of W–Ti and W–TiTa alloys was experimentally investigated under fusion-relevant ion irradiation conditions between 400 and 700 K. In-situ nuclear reaction analysis (NRA) was used to track retention during plasma exposure and subsequent cooldown, providing depth-resolved insight into deuterium accumulation and release. The results show that deuterium retention decreases with increasing temperature for both alloys, consistent with enhanced diffusion and thermally activated detrapping. Clear differences were also observed between the materials: W–Ti exhibits higher apparent activation energies during cooldown, while W–TiTa shows reduced temperature sensitivity, suggesting more stable trapping environments. In addition, retention evolves with fluence in a manner consistent with diffusion-limited behavior, and a small non-monotonic feature near 500 K points to thermally activated redistribution during cooldown. These findings show that alloying tungsten with tantalum modifies how deuterium is stored and transported in the material, offering insight into how plasma-facing materials can be tailored for improved performance in fusion environments.

Keywords

Deuterium retention, tungsten plasma-facing materials, hydrogen isotope diffusion, defect trapping mechanisms, ion beam analysis, thermally activated desorption

Document Type

Thesis

Language

English

Degree Name

Nuclear Engineering

Level of Degree

Masters

Department Name

Nuclear Engineering

First Committee Member (Chair)

Eric Lang

Second Committee Member

Osman Anderoglu

Third Committee Member

Chris Smyth

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