ODIN ready for neutrons

ODIN (“Optical and Diffraction Imaging with Neutrons”), an imaging instrument and one of the first scientific instruments to be completed at the European Spallation Source (ESS) in Lund, Sweden, is now ready for commissioning with neutron radiation. The instrument was developed in close collaboration between the Technical University of Munich (TUM) and the Paul Scherrer Institute (PSI).

Experimental hall_ODIN The experimental section of the ODIN imaging instrument, which can be adapted for samples from various scientific fields. © TUM

The experimental section of the ODIN imaging instrument, which can be adapted for samples from various scientific fields. © TUM

Many scientific questions require a look inside materials and components. Neutrons enable the non-destructive investigation of structures and material properties that are difficult or impossible to access using other imaging techniques. Applications range from batteries and energy technologies, through engineering materials and geomaterials, to biological, archaeological and palaeontological samples. ODIN is the only neutron imaging instrument amongst the initial 15 scientific instruments at the ESS.

50-metre-long neutron guide

ODIN is a highly complex instrument designed to adapt the temporal structure of the ESS’s pulsed neutron beam as flexibly as possible to the specific measurement task. To this end, the instrument extends over a length of around 50 metres from the neutron source to the end of the neutron guide. A key component is the chopper system, comprising nine rotating discs. It modulates the neutron beam over time, enabling specific wavelength ranges to be utilised for measurement. At the end of the neutron guide lies the experimental area, where various detector systems and sample environments can be employed. It is enclosed within a radiation-shielding cave measuring approximately 20 metres in length, 7 metres in width and almost 5 metres in height. The floor area of the cave is around 140 m², which is comparable to the living space of a large five-room flat.

Team picture ODIN A team photo of Aureliano Tartaglione, Elbio Calzada, Manuel Morgano and Virginia Martinez Monge (from left to right), who played a key role in setting up ODIN. © TUM

A team photo of Aureliano Tartaglione, Elbio Calzada, Manuel Morgano and Virginia Martinez Monge (from left to right), who played a key role in setting up ODIN. © TUM

From the very beginning, FRM II played a key role in the development of ODIN. For instance, the design of the chopper system formed part of Dr Philipp Schmakat’s (TUM) doctoral thesis and was developed in close collaboration with Dr Michael Schulz – now Deputy Scientific Director of FRM II – and Dr Marc Seifert. Dr Michael Lerche (TUM) worked as an instrument scientist and project manager to translate the scientific concepts into engineering practice – at a time when the ESS itself was still being established as a new research infrastructure.

Interdisciplinary collaboration

Following Michael Lerche, Dr Aureliano Tartaglione (TUM) took over as project leader at FRM II. Together with Dr Manuel Morgano (his counterpart initially at PSI and later at ESS), as well as lead engineer Elbio Calzada from FRM II, he oversaw the construction of the instrument through the crucial project phases – from the final design decisions, through the procurement and manufacture of the components, to their installation and the final handover to ESS. Engineer Virginia Martinez Monge (TUM) played a key role in the on-site installation in Sweden. She coordinated processes and interfaces between the teams involved and oversaw the implementation of the extensive safety requirements. In the final phase of the project, Dr Robin Woracek (now Head of the Neutron Imaging Group at FRM II) took on the role of scientific lead for ODIN on behalf of the ESS. Together with Dr Aureliano Tartaglione, he oversaw the final installation and preparations for commissioning and carried out the final tests on the instrument components.

“In the case of a metal, for example, we can investigate which crystalline phases or crystal structures it consists of,” explains Robin Woracek, pictured here at the MLZ's ANTARES neutron imaging instrument. © Christoph Leonhardt

“In the case of a metal, for example, we can investigate which crystalline phases or crystal structures it consists of,” explains Robin Woracek, pictured here at the MLZ's ANTARES neutron imaging instrument. © Christoph Leonhardt

“Co-ordinating so many people from different backgrounds and with different skills was challenging. At the same time, it was very encouraging to see how constructively everyone worked together as a team on such a large project. We were all able to learn a great deal from one another in the process,” explains Dr Aureliano Tartaglione. This close collaboration formed the basis for the technical implementation of the instrument.

Imaging with additional information

As with an X-ray, the neutrons pass through the sample and produce a two-dimensional image of its interior. If the sample is rotated and imaged from many different angles, a three-dimensional tomographic image can be reconstructed. One of ODIN’s particular strengths lies in the ESS’s pulsed neutron source. The time taken for the neutrons to travel through the sample can be used to determine the wavelength at which they passed through it. ODIN thus not only provides spatial images, but also information on how the sample weakens neutrons of different wavelengths. Dr Robin Woracek explains: “This allows us not only to see where structures are located within an object, but also to gain additional information about the material itself. In the case of a metal, for example, we can investigate which crystalline phases or crystal structures it consists of – such as whether certain regions are ferritic or austenitic. This additional spectral information thus goes well beyond that provided by conventional radiography or tomography.” This versatility is also reflected in the instrument’s name: ODIN is a reference to the Norse god Odin, the father of the gods, who in mythology symbolises knowledge and versatility.

First experiments planned for 2027

“ODIN is the only imaging instrument to have been realised during the first phase of installation at the ESS and is regarded as a so-called ‘Day-1’ instrument,” explains lead engineer Elbio Calzada. Following a final presentation in December 2025, at which all instrument components, their commissioning and the safety-related aspects and criteria were presented, TUM officially handed over the instrument to the ESS in February 2026. In October 2026, the ESS In-Kind Review Committee – comprising representatives from the countries participating in the ESS – also addressed the formal completion of the project.

All those involved are therefore now focusing on the next phase: the commissioning of ODIN using neutrons. TUM is also expected to play a scientific role in this – both in the commissioning process and in the first scientific experiments, which are scheduled for 2027.