PureAlloys | Dimitra Spathara

The PureAlloys project will advance our understanding in the nature of the Cosmos by enabling novel, extremely radiopure, experimental searches for Dark Matter and for neutrinoless double beta decay.

Current experiments are constrained by radioactive contamination in the detector manufacturing process, posing the main barrier in their physics discovery potential. Electroformed copper achieves extreme radiopurity, however it is limited by its mechanical properties: high ductility and low strength.

funded by UKRI EU Guarantee

PureAlloys will address this challenge by designing high radiopurity CuCr and CuCrTi alloys with significantly higher strength. A novel multi-scale modelling framework enabling fast progress in designing application-specific alloys will be developed, opening the path for the design of new alloys in fields involving fabrication and properties enhancement where the thermodynamic and kinetic description of the system is crucial. PureAlloys will push the boundaries in many fields: from fundamental science to industrial applications.

In the first publication of PureAlloys (Spathara, 2026), simulations using computational thermodynamics are compared with experimental data for the first time. A materials-design approach is proposed for optimising the manufacturing stages of both fabrication and thermal processing.

A study to predict mechanical enhancement with temporal predictions of both solid solution strengthening and precipitation strengthening during aging is also included. A data-driven methodology to design novel radiopure materials for detector systems is proposed.

Many thanks for the time and support I received from my collaborators Kostas Nikolopoulos and Patrick Knights in the Birmingham Particle Physics group, and the world-expert in developing radiopure materials Eric W Hoppe. Our discussions had a massive impact in shaping this endeavour!

Our contribution (Spathara et al., 2025) to the special collection The Direct Detection of Dark Matter in the Underground Laboratory: Past, Present, and Future Prospects, for WIMPs and Non-WIMP Candidates, demonstrates the suggested methodology for designing the Cr/Cu, Cr/Ti and Cr-Ti/Cu layer configurations to achieve homogenized alloys of Cu-0.5Cr and Cu-0.5-0.038Ti (in wt%) composition using electroformation. It also discusses the challenges of manufacturing radiopure CuCr and CuCrTi alloys.

The impact of such alloys to the direct Dark Matter detection and other rare event searches to answer fundamental research questions is demonstrated by two case studies concerning the DarkSPHERE project and the future experiment XLZD. This work leads the way to the next steps of PureAlloys.

References

2026

NIMA

Design of high-strength, radiopure copper–chromium alloys for rare-event searches assisted by computational thermodynamics

Dimitra Spathara

Nuclear Instruments and Methods in Physics Research Section A, 2026

Abs DOI HTML

Direct Dark Matter detection and studies on the nature of neutrinos demand detector systems with extremely low background levels, including from radioactivity. Additive-free, electroformed copper, in addition to a set of advantages, exhibits exceptional radiopurity, making it the material of choice for mechanical and structural components for rare-event searches experiments. To satisfy the increasing demand for materials with superior mechanical strength, the development of copper–chromium alloys is pursued. Early investigations explored the synthesis of these alloys by electrodeposition and thermal processing. A materials-design approach is proposed to optimize the fabrication and thermal processing stages of manufacturing. It is assisted by materials modeling tools based on the thermodynamic and kinetic properties of alloy compositions, which enables faster development of novel materials by predicting properties and materials performance. This approach is demonstrated by comparing simulations with previously reported experimental investigations and proposing improved thermal processing.

2025

CommunPhys

Materials design for the synthesis of high strength radiopure copper alloys for rare event detection

Dimitra Spathara, Patrick Knights, and Konstantinos Nikolopoulos

Communications Physics, Nov 2025

Abs DOI

Additive-free electroformed copper has emerged as the material of choice in exceptionally radiopure detectors for rare-event searches, based on its radiopurity, physical properties, and affordability. However, copper is ductile and of limited mechanical strength posing challenges for its use in future experiments. Electroformed copper-based alloys have been identified as a promising solution. However, their synthesis needs refining by exploring a complex parameter space of compositions and strengthening mechanisms. Here we show how a materials design approach may address current challenges and optimize alloy synthesis and processing. Alloy properties are predicted following thermal processing, using computational thermodynamics. The findings suggest a methodology to design high-performance, radiopure copper-based alloys suitable for next-generation rare-event experiments, while minimizing lengthy and expensive trial-and-error approaches. The impact on future experiments is exemplified through case-studies of the DarkSPHERE and XLZD experiments.