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PSI Facility News IV/2023

Dear Colleagues

Recently, PSI hosted a series of events of importance to the landscape of European photon and neutron (PaN) large-scale research facilities. In November, we welcomed the two European user organizations for PaN science, the European Synchrotron and Free Electron Laser User Organisation (ESUO) and the European Neutron Scattering Association (ENSA), which together represent all users in the European PaN community.

Marc Janoschek

For more information on their meetings, see the editorial by my colleagues Joanna Hoszowska and Annick Froideval at the end of this newsletter.

In December, at the invitation of the Swiss State Secretariat for Education, Research and Innovation (SERI), PSI hosted the Council of the European Spallation Source (ESS), which is set to become the most powerful neutron source in Europe and the world in 2027. PSI is contributing its expertise in neutron instrumentation to the development of five instruments for the ESS project, including the pioneering ESTIA reflectometer. Our local experts gave tours of PSI’s PaN science facilities to ESS Council Chair Robert McGreevy, Vice-Chair Andrea Fischer, ESS Director General Helmut Schober and all the other delegates from the member states, as well as to the State Secretary and the UK Ambassador to Switzerland.

These events highlight how deeply PSI is invested in the future of the European ecosystem of PaN facilities and their user communities. In this sense, it was rewarding to hear the very recent news of the common understanding reached between the European Commission and the Swiss Federal Council to restart negotiations. This renewed understanding is the foundation for Switzerland’s association with Horizon Europe. Notably, the European Research Commission (ERC) has already announced that transitional arrangements will allow them to begin once again accepting applications from researchers based in Switzerland as from the calls under the ERC Work Programme 2024. This is fantastic news as Switzerland's association with Horizon Europe will further strengthen collaboration with the European scientific community and will benefit all PaN facilities and their users.


Marc Janoschek
On behalf of the Laboratory for Muon and Neutron Instrumentation, Research with Neutrons and Muons - NUM 

Next proposal submission deadlines

CHRISP 22 January 2024
SINQ 15 February 2024
SwissFEL 15 March 2024
SµS 01 June 2024

A call for SLS proposals will be announced towards the end of the SLS 2.0 upgrade project. An overview of all proposal submission deadlines of the PSI facilities can be found here.

Research highlights

3D insights into an innovative manufacturing process

SLS — Operando tomographic microscopy during 3D printing of alumina

Today, 3D printing is used in an extremely wide range of fields. The process commonly used for metals and polymers is known as laser powder bed fusion (LPBF). However, the application of LPBF to the additive manufacturing of ceramics remains challenging and tends to produce objects with poor mechanical properties, due to a large number of structural defects. Operando X-ray studies at several synchrotrons around the world, including SLS, have already provided valuable microscopic insights into the complex LPBF printing process. But these studies have been limited to 2D images. Now, a team of researchers working at the TOMCAT beamline has developed a new method to produce time-resolved 3D tomograms and demonstrate that it can capture defects oriented and moving in any direction — thereby providing unprecedent insight into the processes underlying the formation of structural defects.

M. G. Makowska et al., Communications Materials 4, 73 (2023)
DOI: 10.1038/s43246-023-00401-3

More information

Better batteries for electric cars

SINQ — Revealing the impact of temperature in battery electrolytes

The development of batteries for electromobility — and many other applications — is progressing rapidly. But there are still gaps in our understanding of what happens chemically and physically during charging and discharging, especially in liquid electrolytes. New insights have now come from a neutron-imaging study carried out at SINQ, in collaboration with colleagues from ISIS in the UK. The researchers overcame a main limitation for time-of-flight neutron imaging (ToF-NI): the typically long exposure times at pulsed sources. Instead, they developed a high-duty-cycle ToF-NI method suitable for continuous sources such as SINQ. They show that their approach can be used to image physicochemical changes inside battery packs. In particular, they characterised the thermal stability of electrolytes even at sub-freezing conditions — which is challenging with the traditional approach.

E. R. Carreon Ruiz et al., Science Advances 9, eadi0586 (2023)
DOI: 10.1126/sciadv.adi0586

More information

Bronze Age arrowhead is made of meteoritic iron

SμS — Non-destructive analyses prove the meteoritic origin

In an interdisciplinary study led by the Natural History Museum in Bern, researchers have deciphered the origin of the material used to make a Bronze Age arrowhead found in Switzerland. The iron came from a meteorite — a rare source of metallic iron that was available to humans before the smelting from oxide ores started. The complex analysis of the archaeological object was carried out using, among other methods, muon induced X-ray emission (MIXE) spectrometry at SμS. The MIXE study confirmed the nickel-rich composition beneath the oxidized crust, but also the marked difference to material from an iron-meteorite strewn field close to where the artefact was found in the 19th century. Instead, the analysis suggests that the Kaalijarv meteorite, which produced several impact craters in present-day Estonia, is a possible source of the iron used in the arrowhead.

B. A. Hofmann et al., Journal of Archaeological Science 157, 105827 (2023)
DOI: 10.1016/j.jas.2023.105827

More information

First lasing results of Athos

SwissFEL — An X-ray free-electron laser with tailored pulse properties

The Athos soft X-ray beamline of SwissFEL, with its uniquely flexible undulator layout based on short APPLE-X modules and intra-undulator magnetic chicanes, offers control over a wide range of beam properties. The team now reported the first lasing results from Athos, demonstrating control over key pulse properties including polarisation, saturation length, pulse duration and peak power, as well as multi-pulse operation. These results underline the promise of Athos as a versatile beamline for FEL-based science, giving researchers the opportunity to tailor the radiation properties to the specific needs of their experiment — creating new capabilities and thereby opening the door to scientific discoveries.

E. Prat et al., Nature Communications 14, 5069 (2023)
DOI: 10.1038/s41467-023-40759-z

First result from the MEG II experiment

CHRISP — Most stringent limit on the μ⁺→e⁺γ decay

The MEG II experiment started to take data in 2021, after the commissioning of the newly installed sub-detector components and electronics. In a multi-year upgrade programme, all the sub-detectors have been upgraded and their resolution were improved compared to the previous MEG experiment, allowing an increase in sensitivity of about one order of magnitude in the search for the decay of a positive muon into a positron and a photon. The data collected in 2021 are now being analysed and, together with the result from the previous MEG experiment, they provide the most stringent limit on the decay to date. A ten-fold larger sample of data was collected in 2022 and 2023, and data-taking will continue in the coming years.

MEG II collaboration, Preprint at arXiv:2310.12614
DOI: 10.48550/arXiv.2310.12614

More information


Japanese–Swiss BRIDGE Workshop at PSI

BRIDGE stands for “Bridging Research Innovations in Diverse muon and neutron science by General collaboration between Japan and Switzerland”. After a first remote edition of this new workshop series in 2022, an in-person BRIDGE workshop took place at PSI from 18 to 20 October 2023.

Scientists and engineers from KEK, J-PARC and some affiliated Japanese universities, and from PSI and ETH Zurich discussed common technological challenges and developments at their respective facilities for muon and fundamental neutron research. Topics covered a broad range, from proton-beam targets and muon beamlines to 3D-printed components for beam windows and neutron optics. More than 70 participants enjoyed a very open and lively exchange, triggering many follow-up questions for further (joint) studies. The next edition is expected to be organized in Japan in one or two years.

News from the user facilities

SLS: Upgrade of SLS to SLS 2.0

Since the definitive shut down of SLS on 30 September 2023, the dismantling of the old synchrotron has progressed rapidly. The tunnel of 288-m circumference is now empty and the infrastructure refurbishment work is well underway. The preparation of the components for the new ring is advancing in parallel. Around one thousand magnets have to be measured and the strength of the permanent bending magnets needs to be adjusted with high precision. A large fraction of the power supplies for the focusing and corrector magnets has been received. A quarter of the new 18-m vacuum chambers for the ring arcs is ready for installation, and production of the other parts in industry and at PSI is progressing well. Most of the undulators from the old ring will be replaced by new devices. The ten new undulator sources for soft and hard X-ray insertion devices are key components to realize the expected increase in performance. Getting such a large number of new devices ready in time is one of the major challenges of the project, and it will take at least until late 2026 before all of them are available for user operation.

SINQ: Successful collaboration with LLB

The Laboratoire Léon Brillouin (LLB) in Saclay, France, and PSI have an agreement to jointly operate a new small-angle neutron scattering (SANS) instrument at SINQ. The first phase of this collaboration — the transfer of the PA20 instrument from LLB to PSI for building the new SANS-LLB at SINQ — has now been completed. The second phase of the project will start with hot commissioning and friendly users in 2024, following the HIPA winter shutdown. SANS-LLB will be an important instrument for the soft-matter community. We look forward to continuing the collaboration with LLB and the wider French user community.

Following the slightly delayed restart of PSI's proton accelerator in June 2024, it was decided to postpone the next proposal submission deadline to 15 February 2024. The call will open in January.

SμS: Strong demand for beam time

At the latest proposal deadline in early December a total of 151 requests for SμS beam time have been submitted by the user community asking for 712 beam days. Again the GPS instrument received the largest number of proposals (48) followed by FLAME (36), DOLLY (19), GPD (18), LEM (17) and HAL-9500 (13). Together with the spring round, there have been a total of 255 proposals in 2023.

The Scientific Advisory Committee gathers at PSI on 24–25 January 2024. Thereafter we will work on the final schedule and inform the users as soon as possible.

SwissFEL: Bringing SwissFEL light to industrial users

Pharmaceutical companies have a lot to gain from using light from X-ray free electron lasers (XFELs) to study protein structures, but a barrier is throughput. The Cristallina experimental station at SwissFEL, which recently opened its first call for structural biology users, promises to change that. Beamline scientist John Beale, who is responsible for macromolecular crystallography at Cristallina, explains in an interview the main value propositions of serial femtosecond crystallography, and how an increased throughput is achieved at Cristallina-MX.

Read more

CHRISP: First muonic-atom X-ray spectroscopy with a metallic magnetic calorimeter

In October of this year, the QUARTET collaboration performed the first muonic-atom spectroscopy using a metallic magnetic calorimeter. These cryogenic detectors, operating at 15 mK, offer the possibility of broad-band detection of low-energy X-rays with an energy resolution at least a factor of 10 higher than that of the solid-state detectors used so far. Due to the large muon mass, the energies of muonic-atom cascade X-rays are highly sensitive to nuclear structure, opening up the possibility to improve the determination of charge radii in light atoms, where they are currently poorly known. Based on this first successful test, the QUARTET collaboration will now submit a full proposal to PSI to measure absolute charge radii from lithium to neon with substantially increased accuracy.

JUSAP - The Joint Users Association

Dear Colleagues

In collaboration with the Data from Photon and Neutron Experiments (DAPHNE) consortium, user representatives from the European Neutron Scattering Association (ENSA) and the European Synchrotron and Free Electron Laser User Organisation (ESUO) have met at PSI on 13–14 November 2023, for a joint European data policy meeting and a joint ESUO–ENSA meeting.

Joanna Hoszowska

FAIR (Findable, Accessible, Interoperable and Reusable) data principles, and open-data policies for experiments carried out at the LEAPS and LENS research infrastructures (RIs) were discussed, with the aim of working towards the elaboration of a ‘white paper’ discussing how users and RIs can work on these topics to meet their shared responsibility. Details of the meeting can be found here.

That joint meeting was directly followed by the 19th ESUO General Assembly on 15 November 2023. News from the different ESUO national delegations, the NEPHEWS (Neutrons and Photons Elevating Worldwide Science) project, the 6th Plenary Meeting of the League of European Accelerator based-Photon Sources (LEAPS), held at the SOLEIL synchrotron from 18 to 20 October 2023, the ReMade@ARI project, and much more were presented. Many thanks to all involved colleagues, speakers, and participants for such a great event and fruitful exchanges.

We encourage all members of the PSI user community to contact us with any issues relating to user operations at PSI.

With our best wishes for a successful and happy New Year!


Yours sincerely,

Joanna Hoszowska and Annick Froideval
On behalf of the JUSAP committee

Copyright © 2023, Paul Scherrer Institut PSI

The PSI Facility Newsletter addresses the users of the PSI large research facilities and appears quarterly in English. Any feedback is highly welcome! More information. 

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