nTtau Digital at OSSFE 2026

We attended the Open-Source Software for Fusion Energy (OSSFE) Conference in Munich earlier this week, where we had the opportunity to present our latest advancements in neutronics and stellarator design optimisation - all achieved through purely open-source means. The conference continues to be a valuable forum for the fusion community to share progress and network, and it was great to see the breadth of work being carried out across the industry. For our team at nTtau Digital, it provided the perfect platform to showcase how far our capabilities have come since we last presented in 2025.

Over the past year, we have significantly developed our stellarator design workflow. Building on our existing simulation and optimisation work, we have expanded into more advanced support structure design, stress analysis and coil design, bringing together a more complete, end-to-end engineering picture of stellarator machines. As before, this work is carried out using open-source tools, demonstrating that rigorous, production-quality fusion engineering does not require proprietary software. This work is reflected in our first poster 'Automated Stellarator Design using Open-Source Simulation Codes'.

In our second poster, 'Impurity Evolution and Depletion Effects in Breeder Blankets from Reactor Geometry and Material Variations', we explored how breeder blanket performance evolves over time under varying first wall thicknesses and material. By examining metrics such as time-dependent tritium breeding ratio (TBR), neutron-induced reactions, atom inventory and nuclide activity, we were able to assess how blanket thickness and material choices influence long-term behaviour. Understanding and minimising impurity activation is key to ensuring lithium remains an effective neutron absorber for tritium production.

You can view our 2025 posters here.

Poster 1: Automated Stellarator Design using Open-Source Simulation Codes - Sophie Sharpe

Poster 2: Impurity Evolution and Depletion Effects in Breeder Blankets from Reactor Geometry and Material Variations - Luis Garcia-Alen Garcia