Inside the European Spallation Source ESS: Building the World’s Brightest Neutron Laboratory in Lund

The European Spallation Source (ESS) in Lund, Sweden, is a multi‑billion Euro, multi‑nation science facility that uses a powerful proton accelerator to create neutrons for advanced research. This tour explains how spallation works, from generating protons to the 5 MW beam striking a tungsten target wheel to release neutrons. It highlights the massive shielding, the 36‑segment rotating target, and the robotic active cell used to handle radioactive material, all within Europe’s largest science collaboration. The video also covers the instrument suite like Odin, Dream, Magic and Beer, data handling in Copenhagen, and the potential Australia‑level impact on materials science, energy solutions, cancer diagnostics, and quantum technologies. First neutrons are projected for 2026 with full operation by 2027, enabled by in‑kind funding from 13 countries and a budget around €3 billion.

Overview

The European Spallation Source ESS near Lund, Sweden, is a collaboration of more than a dozen European nations designed to produce the world’s brightest neutron beam. The project aims to unlock detailed insights into materials at the atomic level to accelerate advances in energy, healthcare and quantum technologies. The facility is being built to host thousands of researchers annually who will use engineered instruments to study how neutrons interact with matter.

How Neutrons Are Generated

Neutrons are produced not by a reactor but by spallation. A proton beam travels through a high‑vacuum accelerator tunnel toward a tungsten target wheel. The protons strike the tungsten to eject neutrons, which then travel to scientific instruments. The accelerator produces a 5‑megawatt beam at speeds close to the speed of light, roughly 96% of c, and the beam must be precisely controlled at every segment of its journey.

The Accelerator and Target

The accelerator head generates protons that race through a tunnel lined with magnets that keep the beam focused. The protons reach a massive target assembly on the far end, where a 36‑segment wheel spins at 23.3 revolutions per minute. Each rotation must strike every segment and continuously cool the wheel with helium cooling at about 2.8 kg per second. The target and surrounding shielding are extraordinary in scale, including an 8‑metre‑high monolith and a 6000‑ton shielding chamber, designed with precision to protect workers from radiation during operation.

Instruments and Data

At the ends of the beam lines sit a family of interpretation instruments such as Odin, Magic, Dream and Beer. These devices detect how neutrons scatter off samples, enabling researchers to deduce atomic‑level structures. The data from experiments are processed at a dedicated computing center outside Copenhagen, Denmark, before researchers access the results. When fully commissioned, ESS expects about 3000 scientists per year to use the facility.

Collaboration, Funding, and Timeline

ESS represents a joint effort by 13 European nations with an in‑kind funding model where countries contribute knowledge, personnel, and equipment rather than just cash. The total budget is around €3 billion, with roughly half covered by Sweden and Denmark as host nations. Construction began in 2017 and is slated to deliver first neutrons in 2026, with the instruments fully operational by 2027. The facility is designed to blend with the surrounding farmland and even provides waste heat to heat parts of the city of Lund, reflecting a strong commitment to sustainability and community integration.

Impact and Future

By enabling deeper visualization of materials, ESS could drive better energy materials, advanced superconducting magnets for MRI, non‑destructive testing, and potential breakthroughs in quantum computing and other critical technologies. The project illustrates how international collaboration can tackle large, expensive, technologically complex goals more efficiently than any one nation could alone.