Unveiling the Invisible

How ISIS Neutron Source Revolutionizes Condensed Matter Physics

In a laboratory in Oxfordshire, one of the world's most powerful neutron machines is helping scientists see the atomic world in stunning detail, driving breakthroughs in everything from quantum computing to clean energy.

Explore the Science

Imagine being able to watch how atoms move and interact within materials—to see the hidden dance of particles that determines whether a material will conduct electricity without resistance, store energy efficiently, or display exotic magnetic properties. This is not science fiction but everyday reality at the ISIS Neutron and Muon Source, where neutron scattering techniques allow scientists to do exactly that. As one of the world's most powerful pulsed neutron and muon sources, ISIS provides researchers with tools to probe the deepest secrets of condensed matter—the solids and liquids that make up our physical world. From unlocking mysteries of superconductivity to designing better battery materials, the insights gained at this facility are accelerating technological progress across multiple fields.

Why Neutrons? The Ultimate Atomic Microscope

Deep Material Penetration

Unlike other probes like X-rays, which interact with electron clouds, neutrons can penetrate deep into materials and interact directly with atomic nuclei. This allows them to distinguish between light elements that are often invisible to other techniques—a crucial capability when studying hydrogen-containing materials like pharmaceuticals or lithium-ion batteries 1 .

Atomic-Scale Magnetic Sensitivity

The magnetic moment of neutrons makes them uniquely sensitive to magnetism at the atomic scale, enabling researchers to study magnetic materials and superconductors with extraordinary precision 1 . Additionally, because neutrons carry no electrical charge, they can pass through thick layers of material without causing damage.

At ISIS, these remarkable properties are harnessed across 30 specialized neutron instruments that each year host 3,500 user visits, conduct 1,000 experiments, and contribute to approximately 600 scientific publications 1 . This prolific output underscores ISIS's role as a cornerstone of the international condensed matter research community.

The ISIS Advantage: A World-Class Facility for Materials Research

ISIS isn't a single instrument but a suite of specialized tools, each optimized for different types of investigations. The facility generates neutrons not through a nuclear reactor but via spallation—a process where high-energy protons bombarded into a heavy metal target release neutrons. This pulsed neutron source creates intense bursts of neutrons ideal for time-of-flight experiments, where the speed of neutrons after scattering reveals atomic-scale motions and interactions.

Research Areas at ISIS

Quantum Materials

Investigating exotic states of matter, including superconductors, topological materials, and quantum magnets

Energy Materials

Developing better battery components, hydrogen storage materials, and catalysts for clean energy transitions

Soft Matter

Studying polymers, colloids, and biological molecules for applications in drug delivery and synthetic biology

Engineering Materials

Analyzing stresses and strains in structural components, from jet engine turbines to archaeological artifacts

ISIS By The Numbers
30
Specialized Instruments
3,500
User Visits/Year
1,000
Experiments/Year
600
Publications/Year

This broad applicability makes ISIS invaluable not just for academic research but also for industrial innovation, with companies using the facility to improve products and manufacturing processes.

A Closer Look: The Machine Learning Revolution in Neutron Science

In a groundbreaking 2025 study, researchers demonstrated how machine learning could predict the outcome of neutron experiments before they're even conducted 3 . This fusion of computational modeling and experimental validation represents a paradigm shift in how neutron science is performed.

"Predictive simulations could significantly enhance experimental planning and execution by ensuring that data acquisition is optimized for maximum information gain while reducing the likelihood of inconclusive or ambiguous results" 3 .

The research team developed a sophisticated computational workflow that combines:

Density Functional Theory

Accurate electronic structure calculations

Machine-Learned Potentials

Simulate atomic interactions

Molecular Dynamics

Model atomic movements over time

Autocorrelation Analysis

Predict neutron instrument detection

Workflow for Predicting Neutron Experiments from First Principles

Step Component Function Tools Used
1 Machine-Learning Interatomic Potentials Accurately simulate atomic interactions Neuroevolution Potential (NEP) framework
2 Molecular Dynamics Simulations Model atomic movements over time GPUMD package
3 Dynamic Structure Factor Calculation Predict neutron scattering patterns Dynasor package
4 Instrument-Specific Broadening Account for real-world instrument limitations Resolution functions & kinematic constraints

When tested on three representative systems—crystalline silicon, crystalline benzene, and hydrogenated scandium-doped BaTiO₃—the workflow showed remarkable agreement with actual experimental measurements from four different neutron spectrometers 3 . For the hydrogenated scandium-doped BaTiO₃, a material with potential applications in electronics and energy storage, the team trained their model on 2,280 unique structures containing a total of 138,438 atoms—a computational task that would have been unthinkable just a few years ago 3 .

Case Study: Hydrogenated Scandium-Doped BaTiO₃

Aspect Details Significance
System Complexity BaTi₁₋ₓScₓO₃Hₓ Representative of challenging functional materials
Training Data 2,280 structures, 138,438 total atoms Ensures model robustness across configurations
Temperature Range 300-2000K Tests model under extreme conditions
Prediction Accuracy R² = 0.9999 for energies, 0.9792 for forces Near-quantitative agreement with first-principles methods

This approach doesn't just save precious instrument time; it enables researchers to virtually test hypotheses and refine experimental parameters before applying for beamtime.

The Scientist's Toolkit: Essential Resources for Neutron Research

Conducting experiments at a facility like ISIS requires specialized knowledge and tools. The process typically begins with a research proposal submitted through the ISIS online system, with deadlines occurring throughout the year (the next being October 15, 2025) 1 . Brazilian researchers, for instance, benefit from special funding through the UK International Science Partnerships Fund, which covers travel and subsistence costs for experiments conducted between 2023-2027 1 .

Neutron Scattering Techniques and Applications

Technique What It Measures Applications
Inelastic Neutron Scattering Atomic and molecular vibrations Studying hydrogen storage materials, protein dynamics
Neutron Diffraction Atomic crystal structures Determining magnetic structures, locating light atoms
Small-Angle Neutron Scattering Nanoscale structures and morphologies Investigating polymers, colloids, biological macromolecules
Neutron Reflectometry Surfaces and interfaces Studying thin films, membrane proteins, corrosion
Quasielastic Neutron Scattering Slow atomic motions and diffusion Analyzing water transport in batteries, molecular rotation
Training Opportunities

For those new to neutron science, facilities like ISIS offer extensive training opportunities. The Jülich Centre for Neutron Science, for instance, runs a two-week laboratory course that combines theoretical lectures with hands-on experimental training using actual neutron instruments 6 9 .

Brazilian Access Program

The Brazilian Access Program at ISIS includes webinars, workshops, and research visits specifically designed to expand the neutron user community in Brazil 1 .

The Future of Neutron Science: From ISIS to International Collaboration

The impact of ISIS extends far beyond its immediate scientific output. The facility serves as a training ground for the next generation of neutron scientists and maintains active collaborations with research institutions worldwide. One significant partnership involves the Brazilian Multipurpose Reactor (RMB) project in Iperó, where knowledge exchange is helping to build capacity for neutron research in South America 1 .

Upcoming Events

Events like the First Brazilian Neutron User Meeting in January 2026 will bring together researchers from ISIS and Brazilian institutions to share knowledge and plan future collaborations 1 .

Computational Advances

As computational methods continue to advance—with machine learning interatomic potentials enabling simulations of tens of thousands of atoms over several nanoseconds—the synergy between prediction and experiment will only grow stronger 3 .

These international partnerships are crucial for addressing global challenges in energy, healthcare, and technology development. This virtuous cycle of computational guidance and experimental validation promises to accelerate materials discovery at an unprecedented pace.

Conclusion: Seeing the Unseeable, Understanding the Unknowable

The ISIS Neutron and Muon Source represents a remarkable convergence of fundamental physics and practical innovation. By harnessing the unique properties of neutrons, scientists can explore the atomic-scale processes that govern material behavior—knowledge that directly informs the development of better technologies for energy, computing, medicine, and beyond.

The recent integration of machine learning with neutron science exemplifies how the field continues to evolve, offering increasingly sophisticated tools for materials discovery. As these capabilities expand, so too does our ability to design materials with tailored properties—from more efficient superconductors to longer-lasting battery systems.

In the invisible world of atoms and spins, neutrons provide illumination, revealing secrets that once seemed forever beyond our grasp. Facilities like ISIS ensure that these revelations continue to drive scientific progress, answering fundamental questions about the nature of matter while simultaneously building a better technological future.

For those interested in learning more about neutron research or potential collaborations, visit the official ISIS website or explore upcoming events like the Brazilian Neutron User Meeting in January 2026 1 .

References