arXiv subjects

Sara Ferry

Publications and source records attributed to Sara Ferry.

3 recordsLinked to original sources

arXiv2026

SHIELD: A Reference Gas-Driven Permeation Platform for Hydrogen Permeation Studies

A gas-driven permeation (GDP) platform, SHIELD (Salt-compatible Hydrogen barrier Investigation and EvaLuation for fusion Devices), has been developed to measure hydrogen transport properties in structural materials under controlled thermal and pressure conditions. The system is designed to minimise experimental uncertainties associated with leaks, temperature instability, and pressure measurement, while providing reproducible conditions for permeation experiments. The rig operates in a static GDP configuration with independent upstream and downstream volumes, enabling precise control of driving pressure and accurate measurement of downstream pressure rise. An openly documented data acquisition and processing framework is implemented to ensure data traceability and reproducibility. The platform's performance is demonstrated by hydrogen permeation measurements on 316 stainless steel and AISI 1018 low-carbon steel over the temperature range of \SIrange{100}{600}{\degreeCelsius}. Steady-state permeation fluxes are extracted from linear downstream pressure rise and used to determine permeability. The measured permeability exhibits Arrhenius behaviour and agrees well with published literature data for both materials. Permeability measurements are shown to be robust and reproducible. These results demonstrate that SHIELD provides a reliable reference platform for hydrogen permeation measurements and is well-suited to evaluating permeation barrier coatings and advanced materials for fusion applications.

physics.ins-det↗

arXiv2025

BABY 1L: First Tritium Breeding Campaign Results

Achieving tritium self-sufficiency is a critical challenge for future fusion power plants. The BABY 1L experiment, part of the LIBRA project at MIT, aims to benchmark tritium breeding and release in molten salt breeder systems under deuterium-tritium (DT) neutron irradiation. Building on the initial \SI{100}{mL} campaign, BABY 1L introduces a tenfold increase in breeder volume, improved thermal and gas handling systems, and enhanced neutron diagnostics, including a proton recoil telescope. We report on results from four irradiation experiments using sealed-tube DT neutron generators, with tritium collected by water bubblers measured via liquid scintillation counting. Experimentally determined Tritium Breeding Ratios (TBRs) were compared to OpenMC neutronics simulations, showing very good agreement. The measured TBR values demonstrate a six-fold improvement over the \SI{100}{mL} experiments, largely attributed to the increased solid angle and improved measurement fidelity. We also investigate tritium release dynamics and identify diffusion-limited transport as the dominant regime in the salt volume in the temperature range 630-750 \si{\celsius}. Additionally, we observe that the introduction of hydrogen in the helium carrier gas significantly accelerates tritium release, consistent with an isotopic exchange mechanism. All analysis is conducted through the open-source \texttt{libra-toolbox} \cite{libra-toolbox}, which streamlines simulation, data processing, and validation across experimental campaigns. These results provide critical insights into the design and operation of future liquid breeder systems and demonstrate the maturity of the BABY platform as a testbed for tritium breeding studies.

physics.ins-det↗

arXiv2024

Advancing Tritium Self-Sufficiency in Fusion Power Plants: Insights from the BABY Experiment

In the pursuit of fusion power, achieving tritium self-sufficiency stands as a pivotal challenge. Tritium breeding within molten salts is a critical aspect of next-generation fusion reactors, yet experimental measurements of \gls{tbr} have remained elusive. Here we present the results of the \gls{baby} experiment, which represents a pioneering effort in tritium research by utilizing high-energy (\SI{14}{\mega\electronvolt}) neutron irradiation of molten salts, a departure from conventional low-energy neutron approaches. Using a small-scale (\SI{100}{\milli\litre}) molten salt tritium breeding setup, we not only simulated, but also directly measured a \gls{tbr}. This innovative approach provides crucial experimental validation, offering insights unattainable through simulation alone. Moreover, our findings reveal a surprising outcome: tritium was predominantly collected as HT, contrary to the expected TF. This underscores the complexity of tritium behavior in molten salts, highlighting the need for further investigation. This work lays the foundation for a more sophisticated experimental setup, including increasing the volume of the breeder, enhancing neutron detection, and refining tritium collection systems. Such improvements are crucial for advancing our understanding of fusion reactor feasibility and paving the way for future experiments.

physics.plasm-ph↗