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Blazing trails: CMS cavern evacuation paves the way for future safety design Typical evacuation route and signage in the LHC tunnel. (Image: CERN)

CERN strives for excellence in safety matters, with a commitment to continuous improvement in the field. Emergency preparedness is a priority for the Organization as it is a key element in its aim to protect both people participating in its activities and its installations. In this context, regular evacuation exercises of all accelerator and experimental areas are a regulatory requirement and part of the CERN-wide safety objectives.

On a warm, sunny day in February 2024, 48 people were going about their daily work in the CMS cavern, unaware that an evacuation exercise, which had been carefully planned for several months, was about to take place. Such exercises are crucial for facility users and rescue teams to gain familiarity with emergency procedures in various contexts and settings. When the alarm sounded, all 48 people reacted calmly, reaching the assembly point quickly and safely. It was a pleasing result for CMS and, apart from the important lessons learned from the exercise, additional data was gathered to improve not only evacuation procedures but also the design of installations in order to make emergency plans even more effective.

This exercise was part of a pilot collaboration between CMS Safety, the HSE Fire Safety Engineering (FSE) team and the Fire Safety Engineering division of Lund University in Sweden, which took this opportunity to maximise the usefulness of the evacuation to study human behaviour in emergency situations.

Comprising reports by undercover observers, questionnaires and footage from security cameras (used in full compliance with Operational Circular No. 11 to ensure anonymity), the data collected provides many useful insights into evacuation dynamics, occupant characteristics and perceptions of safety procedures.

This information is essential for the design of and emergency planning for subterranean experimental areas. As opposed to the design of buildings located above ground, which follows national safety standards, the design of underground areas relies extensively on computer modelling. Using various parameters, it is possible to simulate human behaviours in the event of an emergency to predict the effectiveness of a real-life evacuation.

In this pilot study, the Lund and FSE teams will use the CMS evacuation data to identify unique human behaviours observed in emergencies in complex underground environments. This will expand the current knowledge base and help build a database of specific input parameters to fine-tune and/or validate existing evacuation models.

Ultimately, this methodology will be instrumental not only to improve CERN’s emergency response in the caverns, but also to influence the safety design across current and future complex facilities, at CERN and beyond.

anschaef Tue, 04/16/2024 - 23:45 Byline CMS collaboration HSE unit Publication Date Wed, 04/17/2024 - 08:43

CERN donates computing equipment to South Africa

On 9 April 2024, a ceremony at CERN marked the donation of computing equipment to the Tshwane University of Technology in South Africa. The ceremony was attended by Mr. Curtis Singo, Political and Economic Counsellor at the South Africa Embassy in Bern, Joachim Mnich, CERN’s director for Research and Computing, and Bob Jones, deputy head of CERN’s IT department.

On this occasion, 21 servers and 4 network switches were sent to the Tshwane University of Technology, where the equipment will be used to support academic and research projects.

CERN regularly donates computing equipment that no longer meets its highly specific requirements but is still more than adequate for less demanding environments. To date, more than 2500 servers and 150 network switches have been donated by CERN to countries and international organisations, namely Algeria, Bulgaria, Ecuador, Egypt, Ghana, Mexico, Morocco, Nepal, Palestine, Pakistan, the Philippines, Senegal, Serbia, Jordan, Lebanon and now South Africa.

If you are a publicly funded research organisation, you can request computing equipment from CERN.

anschaef Tue, 04/16/2024 - 23:21 Byline Marina Banjac Publication Date Tue, 04/16/2024 - 23:20

Fabiola Gianotti receives the 2024 prize from the “Fondation pour Genève” (Image: Fondation pour Genève)

The Fondation pour Genève will be presenting its 30th prize to Fabiola Gianotti, CERN Director-General, in recognition of her outstanding contribution to Geneva’s international reputation.

“I am extremely honoured to receive the Fondation pour Genève Prize. The development of science and technology, openness, collaboration across borders and the education of young people are fundamental values at CERN, which are also deeply rooted in international Geneva. The fact that these values, which are so dear to me, are being recognised is a particularly touching moment for me,” declared Fabiola Gianotti.

The award ceremony is open to everyone and will take place on Monday 13 May 2024 at 6.30 pm at the Victoria Hall in Geneva. To register, click here.

More information on the Fondation pour Genève website.

anschaef Tue, 04/16/2024 - 23:08 Publication Date Wed, 04/17/2024 - 10:05

Handover at the CERN Ombud’s Office

The CERN Ombud’s Office was established in 2010 to provide the entire CERN community with support in resolving conflicts informally, in a consensual and impartial manner. Since then, several Ombuds have held the position, which is now firmly anchored at the Laboratory. On 1 May, Marie-Luce Falipou, the fifth CERN Ombud, will take up her duties. She takes over from Laure Esteveny, who has been in the role since April 2021 and is taking early retirement.

As they prepared for the handover, Laure and Marie-Luce agreed to answer the Bulletin team’s questions.

The Bulletin: Laure, what drove you to become Ombud?

Laure: I began my career as Ombud in 2021, after 35 years working in different departments of the Organization. I was attracted by the human side of the role, and I haven’t been disappointed. I’m extremely happy to have been able to serve out my career as CERN Ombud. It’s very rewarding to help people to overcome a conflict.

The Bulletin: What do you need to succeed in this role?

Laure: When they take up their duties, all new CERN Ombuds follow the training courses run by the International Ombuds Association (IAO) and also receive training in mediation. This is clearly essential, but the skills I acquired throughout my career at CERN have also been invaluable. You need to have good analytical skills and be very thorough to succeed in this role.

Pierre Gildemyn, my predecessor, also supported me a lot. He was always available to answer my questions and shared his own experience as Ombud with me. I, in turn, am available for Marie-Luce; I will be delighted to help her. I would also urge her to turn to the IAO for support and to all the professional ombud networks, especially that of the United Nations and Related International Organizations (UNARIO) – ombuds are very good at supporting each other.

The Bulletin: Have you encountered any difficulties?

Laure: The role of Ombud is very rewarding on the human level. If I had to name a difficulty, I would say that the isolation that inevitably comes with the role is not always easy to cope with. In addition, by definition, the Ombud is only exposed to problematic situations in which people are suffering – to the “Dark Side of the Force” – which can sometimes be a heavy burden.

The Bulletin: Marie-Luce, what brought you to this role?

Marie-Luce: I’ve known Pierre and Laure for a long time, and I’ve seen them thrive in the role of Ombud, for which they developed a real passion. It’s a privilege to be the next to take on this role.

I’ve spent my whole career at CERN, 35 years now, in the Human Resources department. I’ve held various positions, notably HRA (human resources adviser) for 13 years, so I’m very familiar with the workplace culture. I’ve also been trained in active listening – skills that will certainly be very useful in my new position. For me, becoming Ombud is really a natural evolution, even if the role is of course unique.

The Bulletin: You take up your duties on 1 May, but you don’t become Ombud overnight, I imagine?

Marie-Luce: Indeed, I’ll take the necessary time to prepare myself for this new role, which is really something out of the ordinary and something with which I need to familiarise myself. I’m aware of the importance and the impact that the Ombud can have, and I’m humbled and grateful to accept this responsibility.

Le Bulletin: As the new Ombud, what message would you like to send to the CERN community?

Marie-Luce: I want people to know that the Ombud’s office is a safe, calm place where they will be listened to in confidence and understood. The Ombud is there to serve all members of the CERN community, regardless of their role in the Organization. Questions, problems and conflicts are part and parcel of life, including in the workplace. Finding the best way to handle them can make a big difference, and that’s where the Ombud can help.

The Bulletin: Any final words?

Marie-Luce: I’d like to say a big thank you to Laure for sharing her experience with me and for offering me her support; it’s a precious resource to have someone experienced to turn to.

Laure: Thank you to all those who placed their trust in me, and I wish Marie-Luce all the best!

The Bulletin: A big thank you to you both!

_____

The Ombud is available from Monday to Friday in office B500/1-004 on the Meyrin site. To make an appointment, in person or online, contact the Ombud at ombuds@cern.ch.

More information can be found on the Ombud’s website: https://ombuds.web.cern.ch

anschaef Tue, 04/16/2024 - 22:37 Byline Internal Communication Publication Date Tue, 04/16/2024 - 22:31

Accelerator Report: The LHC is well ahead of schedule

Almost the whole accelerator complex is now in “physics mode”, routinely delivering the various types of beam to the different physics facilities and experiments. Notably, the intensity ramp-up in the LHC is progressing remarkably well.

In particular, I am happy to start this report with the good news that, thanks to the excellent availability of the accelerator complex and the hard work of the LHC teams and experts, the LHC is now 12 days ahead of schedule, yielding a direct gain of integrated luminosity and thus physics and boding well for the 2024 run.

The first stable beams of 2024 in the LHC were initially scheduled for 8 April, but the teams working on the LHC beam commissioning managed to be ready earlier and declared first stable beams at 18.25 on 5 April, three days ahead of the official schedule. The first stable beams also mark the start of a period of intensity ramp-up interleaved with the completion of the final commissioning steps.

These final steps include the scrubbing of the LHC vacuum chamber to reduce the production of electron clouds that negatively impact the beam quality and put a strain on the cryogenics system. Usually, the scrubbing lasts two days, but this year an extra day was added since a new injection kicker and two TDIS (target dump injection systems) were installed during the YETS (the new TDIS replace the ones at Points 2 and 8 that suffered vacuum leaks in 2023). The scrubbing run was nevertheless completed in only 36 hours, resulting in another gain in the schedule.

The LHC availability during the recent intensity ramp-up was 85%, including stable beams for about 35% of the time, and the experts very efficiently signed off the checklists at each intensity step. This is why we are now about 12 days ahead of schedule, colliding beams of 1200 bunches and already producing a meaningful level of luminosity for physics. The next step is 1800 bunches, which, if all goes well, might be achieved before the end of this week.

On Tuesday, 16 April, at the end of the afternoon, the first 1.5 fb-1 of integrated luminosity was collected. More than 90 fb-1 are expected for 2024. (Image: CERN)

Meanwhile, the injectors are providing the experiment facilities with beams for physics. The PS was the first to routinely provide beams for physics to the East Area, on 22 March, and n_TOF followed suit on 25 March. ISOLDE, located behind the PS Booster, started physics on 8 April. The SPS fixed-target physics in the North Area started on 10 April. On 15 April, the AWAKE facility located behind the SPS started the first of five two-week proton runs scheduled for 2024. The next in line is the Antimatter factory: the AD and ELENA decelerators should start providing the experiments with antiprotons for physics on 22 April.

The 2024 run has been extended by four weeks, until 25 November, for the LHC, and by five weeks, until 2 December, for the injectors. The YETS will start later this year, which will allow more physics to be done in 2024.

anschaef Tue, 04/16/2024 - 22:27 Byline Rende Steerenberg Publication Date Tue, 04/16/2024 - 22:10

Nature Physics, Published online: 16 April 2024; doi:10.1038/s41567-024-02485-1

Quantum sensing at the megabar frontier

Nature Physics, Published online: 16 April 2024; doi:10.1038/s41567-024-02484-2

Naturally superconducting

Nature Physics, Published online: 16 April 2024; doi:10.1038/s41567-024-02470-8

Bart Verberck uses the musical cent as a pretext to touch on some of the intricacies of musical tuning systems.

Nature Physics, Published online: 16 April 2024; doi:10.1038/s41567-024-02488-y

Eighty years on from the publication of Erwin Schrödinger’s interdisciplinary analysis on the origin of order in living organisms — What is Life? — we look at how physicists and biologists are approaching the topic today.

Nature Physics, Published online: 16 April 2024; doi:10.1038/s41567-024-02468-2

Experience of nature can drive its protection

Mitigating the environmental impact of CERN procurement

Every year, CERN spends some 500 MCHF on goods and services to build, maintain and operate its infrastructure to fulfil its scientific objectives. These purchases not only come at a financial cost, but also have an impact on the environment through the indirect emissions arising from their procurement. In 2023, CERN reported its procurement-related indirect emissions in the CERN Environment Report for the first time. These amounted to 98 030 tCO2e and 104 974 tCO2e in 2021 and 2022 respectively. To put this in context, this represents more than 90% of CERN’s total indirect emissions, the rest being attributed to personnel mobility, duty travel and catering, and just over 30% of CERN’s total emissions.

CERN strives to be a model for environmentally responsible research by taking action on its most impactful domains, including energy and water consumption and emissions, and setting objectives to minimise its environmental footprint. Adopting measures to positively influence procurement-related emissions is a priority for which a comprehensive strategy has been set out that will commit CERN, its suppliers and each and every one of us to making conscious decisions when purchasing goods or services.

Underpinning this strategy, the Environmentally Responsible Procurement Policy was approved by the Enlarged Directorate in June 2023. Anchored in the principle of embedding environmental responsibility where appropriate throughout all phases of the procurement process, the Policy commits the Organization to environmentally responsible procurement and to achieving sustainable results both internally and throughout its supply chains, integrating relevant best practices in its processes, measuring their impact, and communicating with and raising the awareness of all stakeholders.

In December 2023, the Enlarged Directorate approved the implementation of the Policy, effective from 1 January 2024. This entails a one-year kick-off phase to identify suitable areas for policy implementation, including a comprehensive awareness-raising programme with tailored training for technical officers and workshops for the departments focusing on their purchasing activities.

Additionally, pilot projects will help evaluate the integration of environmental criteria into market surveys and invitations to tender. Procurement officers will have access to a supplier sustainability due diligence tool and guidelines outlining best practices. These resources will equip them with the knowledge they need to assess suppliers based on their sustainability efforts.

Furthermore, a supplier engagement programme will be launched in order to foster discussions on sustainability within our supply chains, aiming to collaborate with and encourage suppliers to adopt sustainable practices.

Overall, this comprehensive implementation plan is designed to ensure a smooth transition towards policy compliance and create a sustainable framework for all stakeholders involved. Successful implementation will depend on all actors in CERN’s supply chains challenging our choices and decisions, from CERN’s IPT department, to CERN personnel involved in purchasing, to the suppliers themselves spanning our 23 Member and 11 Associate Member States, while continuing to strive for balanced returns.

According to Chris Hartley, Head of the IPT Department: “It is of great importance that we have established an Environmentally Responsible Procurement Policy for CERN. All CERN stakeholders want to see CERN continue to minimise its environmental impact. This Policy, underpinned by our progressive commitment to responsible sourcing, waste reduction and supplier engagement, will contribute to a more sustainable future.”

ndinmore Mon, 04/15/2024 - 16:39 Byline IPT department Publication Date Mon, 04/15/2024 - 16:35

Nature Physics, Published online: 15 April 2024; doi:10.1038/s41567-024-02473-5

When photons impinge on a material, free electrons can be created by the photoelectric effect. The emitted electron current usually fluctuates with Poisson statistics, but if squeezed quantum light is applied, the electrons bunch up.

ProtoDUNE’s argon filling underway

CERN’s Neutrino Platform houses a prototype of the Deep Underground Neutrino Experiment (DUNE) known as ProtoDUNE, which is designed to test and validate the technologies that will be applied to the construction of the DUNE experiment in the United States.

Recently, ProtoDUNE has entered a pivotal stage: the filling of one of its two particle detectors with liquid argon. Filling such a detector takes almost two months, as the chamber is gigantic – almost the size of a three-storey building. ProtoDUNE’s second detector will be filled in the autumn.

ProtoDUNE will use the proton beam from the Super Proton Synchrotron to test the detecting of charged particles. This argon-filled detector will be crucial to test the detector response for the next era of neutrino research. Liquid argon is used in DUNE due to its inert nature, which provides a clean environment for precise measurements. When a neutrino interacts with argon, it produces charged particles that ionise the atoms, allowing scientists to detect and study neutrino interactions. Additionally, liquid argon's density and high scintillation light yield enhance the detection of these interactions, making it an ideal medium for neutrino experiments.

Interestingly, the interior of the partially filled detector now appears green instead of its usual golden colour. This is because when the regular LED light is reflected inside the metal cryostat, the light travels through the liquid argon and the wavelength of the photons is shifted, producing a visible green effect.

The DUNE far detector, which will be roughly 20 times bigger than protoDUNE, is being built in the United States. DUNE will send a beam of neutrinos from Fermi National Accelerator Laboratory (Fermilab) near Chicago, Illinois, over a distance of more than 1300 kilometres through the Earth to neutrino detectors located 1.5 km underground at the Sanford Underground Research Facility (SURF) in Sanford, South Dakota.

Watch a short time-lapse video of protoDUNE being filled with liquid argon:

ckrishna Fri, 04/12/2024 - 10:15 Byline Chetna Krishna Publication Date Fri, 04/12/2024 - 10:30

Nature Physics, Published online: 12 April 2024; doi:10.1038/s41567-024-02456-6

As amorphous solids, glasses and gels are similar, but the origins of their different elastic properties are unclear. Simulations now suggest differing free-energy-minimizing pathways: structural ordering for glasses and interface reduction for gels.

The next-generation triggers for CERN detectors

The experiments at the Large Hadron Collider (LHC) require high-performance event-selection systems – known as “triggers” in particle physics – to filter the flow of data to manageable levels. The triggers pick events with distinguishing characteristics, such as interactions or collisions of particles recorded in particle detectors, and make them available for physics analyses. In just a few seconds, the complex system can determine whether the information about a given collision event is worth keeping or not. 

The ATLAS and CMS experiments use triggers on two levels. The first trigger runs in sync with the rate of particle bunches colliding in the detectors, deciding in less than 10 microseconds which data to keep. Events that pass the first-level trigger move on to the second high-level trigger for further selection. The selected events are then sent to the CERN Data Centre, where the data is copied, stored and eventually made available to scientists around the world for data analysis.  

In preparation for the High-Luminosity LHC (HL-LHC), the ATLAS and CMS detectors are being upgraded with finer spatial and timing granularity, which will result in more data for each collision. The principle is the same as taking a picture with a camera with more pixels: the resulting file will be bigger because the image contains more detail, and the picture will be of higher quality. To prepare for the data deluge expected when the LHC enters the high-luminosity era, scientists need to develop new strategies for more sophisticated event processing and selection.

The key objective of the five-year Next-Generation Triggers (NextGen) project is to get more physics information out of the HL-LHC data. The hope is to uncover as-yet-unseen phenomena by more efficiently selecting interesting physics events while rejecting background noise. Scientists will make use of neural network optimisation, quantum-inspired algorithms, high-performance computing and field-programmable gate array (FPGA) techniques to improve the theoretical modelling and optimise their tools in the search for ultra-rare events.

The foundations of the NextGen project were laid in 2022 when a group of private donors, including former Google CEO Eric Schmidt, visited CERN. This first inspiring visit eventually evolved into an agreement with the Eric and Wendy Schmidt Fund for Strategic Innovation, approved by the CERN Council in October 2023, to fund a project that would pave the way for the future trigger systems at the HL-LHC and beyond: NextGen was born.

NextGen will collaborate with experts in academia and industry. The work builds on the open-science and knowledge-sharing principles embedded in CERN's institutional governance and modus operandi. The project includes a work package dedicated to education and outreach, a unique multi-disciplinary training programme for NextGen researchers and targeted events and conferences for the wider community of scientists interested in the field. The intellectual property generated as part of the NextGen Triggers project, owned by CERN, will be released and shared under open licences in compliance with the CERN Open Science Policy.

The NextGen Triggers project will mark a new chapter in in high-energy physics, leveraging upgraded event-selection systems and data-processing techniques to unlock a realm of discoveries.  

ckrishna Thu, 04/11/2024 - 11:45 Byline Antonella Del Rosso Publication Date Thu, 04/11/2024 - 12:00

Searching for new asymmetry between matter and antimatter The LHCb detector seen in 2018 during its opening (Image: CERN)

Once a particle of matter, always a particle of matter. Or not. Thanks to a quirk of quantum physics, four known particles made up of two different quarks – such as the electrically neutral D meson composed of a charm quark and an up antiquark – can spontaneously oscillate into their antimatter partners and vice versa.

At a seminar held recently at CERN, the LHCb collaboration at the Large Hadron Collider (LHC) presented the results of its latest search for matter–antimatter asymmetry in the oscillation of the neutral D meson, which, if found, could help shed light on the mysterious matter–antimatter imbalance in the Universe.

The weak force of the Standard Model of particle physics induces an asymmetry between matter and antimatter, known as CP violation, in particles containing quarks. However, these sources of CP violation are difficult to study and are insufficient to explain the matter–antimatter imbalance in the Universe, leading physicists to both search for new sources and to study the known ones better than ever before.

In their latest endeavour, the LHCb researchers have rolled up their sleeves to measure with unprecedented precision a set of parameters that determine the matter–antimatter oscillation of the neutral D meson and enable the search for the hitherto unobserved but predicted CP violation in the oscillation.

The collaboration had previously measured the same set of parameters, which are linked to the decay of the neutral D meson into a positively charged kaon and a negatively charged pion, using its full data set from Run 1 of the LHC and a partial data set from Run 2. This time around, the team analysed the full Run-2 data set and, by combining the result with that of its previous analysis, excluding the partial Run-2 data set, it obtained the most precise measurements of the parameters to date – the overall measurement uncertainty is 1.6 times smaller than the smallest uncertainty achieved before by LHCb.

The results are consistent with previous studies, confirming the matter–antimatter oscillation of the neutral D meson and showing no evidence of CP violation in the oscillation. The findings call for future analyses of this and other decays of the neutral D meson using data from the third run of the LHC and its planned upgrade, the High-Luminosity LHC.

Other neutral D meson decays of interest include the decay into a pair of two kaons or two pions, in which LHCb researchers observed CP violation in particles containing charm quarks for the first time, and the decay into a neutral kaon and a pair of pions, with which LHCb clocked the speed of the particle’s matter–antimatter oscillation. No avenue should be left unexplored in the search for clues to the matter–antimatter imbalance in the Universe and other cosmic mysteries.

Find out more on the LHCb website.

abelchio Thu, 04/11/2024 - 11:41 Byline Ana Lopes Publication Date Thu, 04/11/2024 - 17:00

Nature Physics, Published online: 11 April 2024; doi:10.1038/s41567-024-02500-5

Author Correction: Cooperative pattern formation in multi-component bacterial systems through reciprocal motility regulation

Nature Physics, Published online: 11 April 2024; doi:10.1038/s41567-024-02448-6

Questioning the validity of axioms can teach us about physics beyond the standard model. A recent search for the violation of charge conservation and the Pauli exclusion principle yields limits on these scenarios.

Nature Physics, Published online: 11 April 2024; doi:10.1038/s41567-024-02474-4

Controlling phase transitions in solids is crucial for many applications. Ultrafast laser pulses have now been shown to enable the energy-efficient generation of structural fluctuations in VO2 by harnessing the correlated disorder in the material.

Nature Physics, Published online: 11 April 2024; doi:10.1038/s41567-024-02451-x

Linear topological systems can be characterized using invariants such as the Chern number. This concept can be extended to the nonlinear regime, giving rise to nonlinearity-induced topological phase transitions.