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Lithuania becomes Associate Member State of CERN

Mon, 01/08/2018 - 12:21

CERN Director General, Fabiola Gianotti, the Minister of Foreign Affairs of the Republic of Lithuania, Linas Linkevičius, and the President of the Republic of Lithuania, Dalia Grybauskaitė at the signing of the agreement (Image: Julie Haffner/ CERN)

Today, the Republic of Lithuania became an Associate Member State of CERN. This follows official notification to CERN that the Republic of Lithuania has completed its internal approval procedures, as required for the entry into force of the Agreement, signed in June 2017, granting that status to the country.

Lithuania’s relationship with CERN dates back to 2004, when an International Cooperation Agreement was signed between the Organization and the government of the Republic of Lithuania setting priorities for the further development of scientific and technical cooperation between CERN and Lithuania in high-energy physics. One year later, in 2005, a Protocol to this Agreement was signed, paving the way for the participation of Lithuanian universities and scientific institutions in high-energy particle physics experiments at CERN.

Lithuania has contributed to the CMS experiment since 2007 when a Memorandum of Understanding (MoU) was signed marking the beginning of Lithuanian scientists’ involvement in the CMS collaboration. Lithuania has also played an important role in database development at CERN for CMS data mining and data quality analysis. Lithuania actively promoted the BalticGrid in 2005.

In addition to its involvement in the CMS experiment, Lithuania is part of two collaborations that aim to develop detector technologies to address the challenging upgrades needed for the High-Luminosity LHC.

Since 2004, CERN and Lithuania have also successfully collaborated on many educational activities aimed at strengthening the Lithuanian particle physics community. Lithuania has been participating in the CERN Summer Student programme and 53 Lithuanian teachers have taken part in CERN’s high-school teachers programme.

The associate membership of Lithuania strengthens the long-term partnership between CERN and the Lithuanian scientific community. Associate Membership allows Lithuania to take part in meetings of the CERN Council and its committees (Finance Committee and Scientific Policy Committee). It also makes Lithuanian scientists eligible for staff appointments. Finally, Lithuanian industry is henceforth entitled to bid for CERN contracts, thus opening up opportunities for industrial collaboration in areas of advanced technology.

CERN wishes you Happy New Year 2018

Fri, 12/22/2017 - 14:54

(Video: Daniel Dominguez/CERN)

CERN wishes you Happy New Year 2018.

In 2017, CERN pushed the limits of knowledge with many new developments. Its flagship machine, the Large Hadron Collider (LHC), collected a staggering amount of data, accumulating 5 million billion proton-proton collisions.

In 2018, the LHC begins its final year of data-taking before the second long technical stop. This technical stop, set to last from late 2018 to early 2021, will allow CERN’s technicians, engineers and physicists to renovate and improve the accelerator complex, as well as the experiment collaborations to prepare their detectors to fully exploit the future higher luminosity of the machine.

Whether with the LHC or with the many other research facilities, the year looks set to promise many scientific and technological advances to enrich our understanding of particle physics and to benefit society as a whole.

CERN 2017 highlights: a year in images

Fri, 12/22/2017 - 10:05

 

(Video: Noemi Caraban/CERN)

This year has been rich with new facilities for research and applications, physics results that enrich human knowledge and international collaborations that bring together more countries, as well as programmes to train and educate thousands of students and teachers. This video showcases the highlights of 2017 at CERN.

Find out more details about these events on the “updates” page.

See you next year for new adventures to the limits of knowledge and technology.

Forty years since the first PET image at CERN

Thu, 12/21/2017 - 15:54

On a peaceful afternoon in early summer 1977, the laboratory of CERN radiobiologist Marilena Bianchi was visited by a physicist with a pretty unusual request. He asked for her help in his quest to create a first image of a mouse using a PET (positron-emission tomography) camera.

The physicist, David Townsend, had been helping Alan Jeavons, also a physicist at CERN. Jeavons had developed a new detector, based on a high-density avalanche chamber, to take PET images. Townsend had developed the software to reconstruct the data from the detector and to turn them into an image.

Once they were ready, Townsend asked Bianchi, who was developing medical applications of CERN technologies, to inject a mouse with a small amount of short-lived radioisotope, which was absorbed into the skeleton of the animal.

The first PET image taken at CERN, in 1977, showing the skeleton of a mouse. Unlike a modern-day image, this one is truly digital – it is composed of numbers. Each number indicates how much of the isotope has been emitted at each point. (Image: CERN)

The isotope she injected emitted positrons, the antimatter twins of electrons. These positrons bumped into nearby electrons and in the collision a pair of photons was created. The photons shot out in exactly opposite directions. By placing two detectors around the mouse, Jeavons and Townsend picked up these pairs of photons, pinpointing where the positron annihilations occurred. “A few days later, David Townsend came back with this beautiful picture. The first mouse scan taken with a PET camera,” remembers Streit-Bianchi. “The findings were then presented at a conference in October 1977.”

PET was not invented at CERN, but the work carried out by Jeavons and Townsend made a major contribution to its development, thanks to the type of detector and computer programme developed for image-taking analysis. After the initial success, Jeavons and Townsend devoted their careers to improving medical imaging. Later, Townsend and co-workers in the US suggested to combine PET-CT (computed tomography) to see both metabolic and anatomic information. This was a major breakthrough for cancer diagnosis and treatment follow up.

“I am very proud. The inventiveness of these two physicists and their desire to develop a special PET camera resulted in the further development of a perfectly safe method to inquire what is happening in the body.” - Streit-Bianchi

Forty years on, PET technology is even more advanced thanks to the work carried out at CERN and other research laboratories around the world. The technologies and scientific advances behind high-energy physics – through developments in accelerators, detectors and computing – have helped to contribute to the field of medical imaging.

Twenty years ago, with Marilena Streit-Bianchi’s help, CERN established a dedicated policy and structure for knowledge and technology transfer. The CERN group of the Crystal Clear Collaboration is now developing new fast detector prototypes for use in both high-energy physics experiments and medical imaging, with particular emphasis on the PET technology. Read more about Streit-Bianchi’s 41-year career at CERN in the September 2014 CERN Courier.

Find out more about PET at CERN in the June 2005 CERN Courier.

CMS releases more than one petabyte of open data

Wed, 12/20/2017 - 11:15

A collision event recorded by CMS in 2012 showing a “Higgs candidate”, available on the CERN Open Data portal with the latest release of CMS Open Data. (Image: Tom McCauley/CMS/CERN)

The CMS Collaboration at CERN have just made public around half of the data collected in 2012 by the CMS detector at the Large Hadron Collider. This release includes sets used to discover the Higgs boson, and is being shared through the CERN Open Data portal.

This is the third release of high-level CMS Open Data, following the release of 2010 data in 2014, and 2012 data in 2016. This batch contains more than 550 terabytes of proton-proton collision data recorded at a centre-of-mass energy of 8 TeV as well as around 510 petabytes of Monte Carlo simulation data.

LHC data are complicated and big. CMS researchers have recorded petabytes of data from collisions at the LHC and have so far published hundreds of scientific papers with them. By releasing the data into the public domain, researchers outside the CMS Collaboration have the opportunity to conduct novel research with them.

“Our data are an important element of the CMS Collaboration’s rich scientific legacy,” says CMS Spokesperson, Joel Butler. “We would like to ensure that they are not only preserved in the long run but are also available to the public, so that both CMS members and external researchers can re-examine them in the future. This is part of our commitment to openness and long-term data preservation.”

Animation showing a "Higgs candidate" event, recorded by CMS in 2012 and available on the CERN Open Data portal with the latest release of CMS Open Data. (Image: Tom McCauley and Achintya Rao CMS/CERN)

Recently, the first two such research papers were published by a team of theorists at MIT interested in performing a measurement CMS scientists had themselves not done: specifically they wanted to measure particular substructures in clusters of particles known as “jets” produced in proton-proton collisions.

The latest release of CMS Open Data also carries the fascinating possibility of allowing people to repeat the analysis that led to the Higgs discovery by studying the same data used by CMS scientists to announce the particle’s existence in 2012. As a proof of concept, CMS doctoral student Nur Zulaiha Jomhari analysed CMS Open Data and produced plots similar to some of those shown when the Higgs discovery was announced. This analysis is a lot less sophisticated than the official CMS one and is not scrutinised by the wider CMS community of experts, but it demonstrates the potential of CMS Open Data.

Left: The official CMS plot for the “Higgs to four leptons” channel, shown on the day of the Higgs discovery announcement. Right: A similar plot produced by Nur Zulaiha Jomhari et al. using CMS Open Data from 2011 and 2012. Although the plots appear similar, the analysis with CMS Open Data uses more data (at 8 TeV and overall) than the official CMS one from the original discovery but is a lot less sophisticated and is not scrutinised by the wider CMS community of experts. (Image: CMS/CERN)

In addition to the datasets themselves, the CMS Data Preservation and Open Data team has also assembled a comprehensive collection of supplementary materials, including example code for performing relatively simple analyses, as well as metadata such as information on how data were selected and what the LHC’s running conditions were during the time of data collection.

At the moment, CMS has committed to releasing up to 50% of each year’s recorded data a few years after they were collected, once CMS scientists finish most of their analysis of these datasets. “To see our open data in use outside CMS has been very rewarding,” says Kati Lassila-Perini, the CMS Data Preservation and Open Access co-coordinator. “It has been a great motivation for us and we look forward to continuing our pioneering efforts to release research-quality open data from the LHC in the years to come.”

Read more about this release in the CMS announcement

LHC experiments highlight 2017 results

Tue, 12/19/2017 - 14:16

The LHC experiments presented highlights from their 2017 results on 15 December, during a symposium celebrating 25 years of the LHC experimental programme. (Image: Julien Ordan/ CERN)

Particle physicists like to plan; constructing some of the largest machines in the world needs a long-term vision. Although physics data-taking at the Large Hadron Collider (LHC) began in 2010, the LHC experimental programme can in fact be traced back to the Evian meeting in 1992. To celebrate this 25th anniversary, on 15 December CERN held a symposium to look back at the history and the bold decisions needed to realise the immense detectors and vast worldwide collaborations. The event concluded with the four large LHC experiments – ALICE, ATLAS, CMS and LHCb – reviewing their recent experimental results.  

Delving into the extreme physics of heavy-ion collisions, ALICE studies a state of matter that existed just after the Big Bang called the quark-gluon plasma (QGP). QGP is known to behave as a near perfect fluid, and physicists have measured flow coefficients noting stronger flow at larger energies, consistent with huydrodynamic calculations. Latest results on a parameter called elliptic flow in lead-lead and proton-lead collisions show that even the heavy charm quarks follow the fluid expansion, helping physicists to understand more about the QGP evolution. Another key probe of this primordial state is the study of the strange quark, and this year’s results included novel phenomena in strange-particle production in proton collisions that show similar patterns to what is observed in heavy-nuclei collisions.

Using the LHC’s high-energy proton-proton collisions, physicists are rigorously testing the Standard Model. This model, which explains how the basic building blocks of matter interact, has so far withstood the most rigorous of tests. But physicists know it is uncomplete and are determined to find chinks in this model’s armour to reveal new and as yet undiscovered particles and phenomena. The Standard Model’s cornerstone is the Higgs boson. With its discovery announced at CERN in 2012, this newest addition to the elementary particles remains one of the most active areas of research for LHC physicists, and studying its properties has been a quest for both the ATLAS and CMS collaborations.

This year saw several new results of Higgs boson interactions with the heaviest “third-generation” elementary particles: bottom quarks and tau leptons. ATLAS and CMS used data from 2015 and 2016 to establish evidence for Higgs boson decays to two bottom quarks. CMS also presented a “5-sigma” observation of Higgs boson decays to two tau particles. Both ATLAS and CMS saw evidence of “ttH production”, one of the rarest processes measured at the LHC in which a pair of top quarks emits a Higgs boson. This could provide new insights into the Higgs mechanism and perhaps open the door to unknown physics.

The top quark, heavier than the Higgs boson, and in fact all the other elementary particles, also provided a rich ground for investigations this year. ATLAS and CMS joined forces and combined some of their key top quark measurements from proton-proton collisions, including evidence for the associated production of a top quark and a Z boson, a rare electroweak process in the Standard Model. In addition, for the first time, CMS observed top quarks produced in proton-lead collisions. ATLAS also presented high-precision measurements of the top quark mass, which, in combination with the collaboration’s precision measurements of the mass of the W and Higgs bosons, tests the consistency of the Standard Model. CMS also measured the forward-backward asymmetry in Z boson decays to electrons and muons, providing the most precise LHC measurement of the weak mixing angle obtained so far at the LHC.

The elusive physics “beyond the Standard Model” (BSM) remains tantalising for LHC researchers. BSM searches for new particles including supersymmetric particles were aplenty across the experimental collaborations. Despite no conclusive signs of new physics, the experimental results have helped tighten constraints on different models and possibilities, homing in on the most exciting areas of investigation ahead.

One of the most intriguing results comes from LHCb and shows slight anomalies in the way leptons (electrons, muons and tau particles) behave. This potentially challenges a fundamental Standard Model principle known as lepton-flavour-universality and will be a key area of investigation in 2018. LHCb also hit the headlines this year with the discovery of five new particles at once (all slightly different versions of the so-called omega-c baryon) – possibly a record number of new particles for a single publication. Later in the year, the collaboration announced the first observation of a doubly charmed baryon, the first doubly heavy quark particle ever seen. With one trillion beauty hadrons (particles containing a beauty quark) produced at LHCb this year, the collaboration continues to investigate matter-antimatter asymmetry, with results so far being consistent with the Standard Model.

After this year’s great LHC machine performance, physicists are only now beginning to delve into 2017 data as they look ahead to 2018. These physicists like to plan, and indeed, work towards the LHC upgrade, High-Luminosity LHC expected after 2025, has begun in earnest. With the LHC set to continue churning out data at an astounding rate, not only is it a moment to look back at the last 25 years, it is also a chance to look forward to the wealth of undiscovered knowledge that lies ahead. 

A new compact accelerator for cultural heritage

Tue, 12/19/2017 - 09:20

CERN and INFN are developing a new transportable accelerator, which will be used to analyse works of art at the laboratories of the Opificio delle Pietre Dure in Florence. (Image: INFN)

Beyond fundamental research, accelerators are well known for their contribution to the medical field, especially in cancer therapy. However, they can help more unexpected patients: historical finds and works of art.

CERN and the Italian National Institute for Nuclear Physics (INFN), through its cultural heritage network CHNet, are collaborating to develop the next generation of accelerators dedicated to cultural heritage.

The project, named MACHINA (Movable Accelerator for Cultural Heritage In-situ Non-destructive Analysis), aims to build a compact, transportable accelerator, based on radio-frequency quadrupole technology developed at CERN.

This new transportable accelerator, fully dedicated to cultural heritage applications, will be based at the laboratories of the Opificio delle Pietre Dure in Florence.

Thanks to its relatively small size and weight – less than 2-metres-long and 300 kg – it will be possible to transport the new accelerator to analyse in situ large immovable works, such as frescoes, or works too fragile to be transported. Accelerators are used to date the works with the carbon-14 method and for analysing the constituent material of a work in a non-destructive manner.

To learn more about MACHINA, read the INFN press release

Arts at CERN’s Collide International award now open

Mon, 12/18/2017 - 11:19

The National Apavilion of Then and Now, a piece by artist Haroon Mirza, who founded the studio platform hrm199, winner of the Collide International Award in 2017. (Image: Kiki Triantafyllou, courtesy of hrm199 and Lisson Gallery)

Today, Arts at CERN has announced a new edition of the Collide International award, in partnership with the UK’s leading media arts centre, FACT (Foundation for Art and Creative Technology). The competition is open to artists of any age and from anywhere in the world whose work reflects on the cultural and social understanding of science and advanced knowledge.

Collide International was created to challenge and transform the way in which encounters between art and science are understood and the influence of science on new methods of artistic expression. The winning artist will benefit from a fully funded residency, the first two months of which will be spent at CERN, Geneva, followed by a one-month stay at FACT in Liverpool.

“Collide has become an influential platform that enriches the cultural dynamics of the Laboratory; it brings together science and art to inspire each other in new creative forms that help to enhance our understanding of the world around us”, says Charlotte Lindberg Warakaulle, CERN Director for International Relations.

Collide offers the winning artist an exclusive opportunity to spend time among scientists and engineers in CERN’s groundbreaking research environment, providing an inspirational place to explore and expand their research in order to find new means of artistic expression. After the CERN residency, FACT, with its collaborative spirit and wide-ranging programme of exhibitions and participant-led art projects, will offer the artist an excellent setting in which to reflect on and contextualise his or her work.

“For the third year running, we are coming together with CERN to give one artist a once-in-a-lifetime chance to explore, research, question and create. We bring art, technology and people together in a think-can-do-tank of immense possibilities between CERN and FACT Liverpool”, says Professor Mike Stubbs, Director of FACT.

“The primary objective of Collide is to open up exceptional opportunities for dialogue and exchange between artists and scientists and to encourage significant connections between both types of creative mind”, affirms Mónica Bello, Head of Arts at CERN.

Guidelines for the international open call have now been released and applications will be accepted here from today until 15 February 2018. 

25 years of Large Hadron Collider experimental programme

Thu, 12/14/2017 - 16:14

This week CERN marks 25 years since the meeting at Evian, where the first ideas for the LHC experimental programme were debuted (Image: Maximilien Brice/CERN)

On Friday 15 December 2017, CERN is celebrating the 25th anniversary of the Large Hadron Collider (LHC) experimental programme. The occasion will be marked with a special scientific symposium looking at the LHC’s history, the physics landscape into which the LHC experiments were born, and the challenging path that led to the very successful LHC programme we know today.

The anniversary is linked to a meeting that took place in 1992, in Evian, entitled Towards the LHC Experimental Programme, marking a crucial milestone in the design and development of the LHC experiments.

The symposium, which will be live webcast, will also include a presentation of the latest results from the four large experiments, ATLAS, CMS, LHCb and ALICE.

Join the live webcast from 11:00-16:00 CET.

Breaking data records bit by bit

Thu, 12/14/2017 - 09:57

Magnetic tapes, retrieved by robotic arms, are used for long-term storage (Image: Julian Ordan/CERN)

This year CERN’s data centre broke its own record, when it collected more data than ever before.

During October 2017, the data centre stored the colossal amount of 12.3 petabytes of data. To put this in context, one petabyte is equivalent to the storage capacity of around 15,000 64GB smartphones. Most of this data come from the Large Hadron Collider’s experiments, so this record is a direct result of the outstanding LHC performance, the rest is made up of data from other experiments and backups.

“For the last ten years, the data volume stored on tape at CERN has been growing at an almost exponential rate. By the end of June we had already passed a data storage milestone, with a total of 200 petabytes of data permanently archived on tape,” explains German Cancio, who leads the tape, archive & backups storage section in CERN’s IT department.

The CERN data centre is at the heart of the Organization’s infrastructure. Here data from every experiment at CERN is collected, the first stage in reconstructing that data is performed, and copies of all the experiments’ data are archived to long-term tape storage.

Most of the data collected at CERN will be stored forever, the physics data is so valuable that it will never be deleted and needs to be preserved for future generations of physicists.

“An important characteristic of the CERN data archive is its longevity,” Cancio adds. “Even after an experiment ends all recorded data has to remain available for at least 20 years, but usually longer. Some of the archive files produced by previous CERN experiments have been migrated across different hardware, software and media generations for over 30 years. For archives like CERN’s, that do not only preserve existing data but also continue to grow, our data preservation is particularly challenging.”

While tapes may sound like an outdated mode of storage, they are actually the most reliable and cost-effective technology for large-scale archiving of data, and have always been used in this field. One copy of data on a tape is considered much more reliable than the same copy on a disk.

CERN currently manages the largest scientific data archive in the High Energy Physics (HEP) domain and keeps innovating in data storage,” concludes Cancio.

Explore CERN in the world of Minecraft

Wed, 12/13/2017 - 11:29

Students have recreated CERN and the ATLAS laboratory in detail using Minecraft’s signature 3D blocks (Image: ATLAS)

Now you can discover CERN and the ATLAS detector in incredible detail on the gaming platform Minecraft, through ATLAScraft, launched today.

The virtual world recreates the Laboratory using Minecraft’s signature 3D blocks, in an interactive museum and map that includes striking images accompanied by detailed explanations and mini-games to explore the world of particle physics.

The centrepiece of the game is a stunning scale model of the ATLAS experiment, complete with underground service caverns and tunnels for the Large Hadron Collider (LHC). Players can slice open the experiment to reveal layers of subdetectors, watch particles meet at the ATLAS collision point, and play minigames that explain how each subdetector works.

This virtual world was created by UK secondary school students together with ATLAS physicists, in a project funded by the UK’s Science and Technology Facilities Council (STFC) and the ATLAS Experiment. With the help of experts, the students became the teachers in ATLAScraft, turning their new knowledge of the detector and particle physics into engaging activities for players.

Explore CERN through the new ATLAScraft game (Video: ATLAScraft)

New CERN facility can help medical research into cancer

Tue, 12/12/2017 - 14:10

As in the ISOLDE facility, the targets at MEDICIS have to be handled by robots because they are radioactive (Image: Maximilien Brice/CERN)

Today, the new CERN-MEDICIS facility has produced radioisotopes for medical research for the first time. MEDICIS (Medical Isotopes Collected from ISOLDE) aims to provide a wide range of radioisotopes, some of which can be produced only at CERN thanks to the unique ISOLDE facility. These radioisotopes are destined primarily for hospitals and research centres in Switzerland and across Europe. Great strides have been made recently in the use of radioisotopes for diagnosis and treatment, and MEDICIS will enable researchers to devise and test unconventional radioisotopes with a view to developing new approaches to fight cancer. 

“Radioisotopes are used in precision medicine to diagnose cancers, as well as other diseases such as heart irregularities, and to deliver very small radiation doses exactly where they are needed to avoid destroying the surrounding healthy tissue,” said Thierry Stora, MEDICIS project coordinator. “With the start of MEDICIS, we can now produce unconventional isotopes and help to expand the range of applications.”

A chemical element can exist in several variants or isotopes, depending on how many neutrons its nucleus has. Some isotopes are naturally radioactive and are known as radioisotopes. They can be found almost everywhere, for example in rocks or even in drinking water. Other radioisotopes are not naturally available, but can be produced using particle accelerators. MEDICIS uses a proton beam from ISOLDE – the Isotope Mass Separator Online facility at CERN – to produce radioisotopes for medical research. The first batch produced was Terbium 155Tb, which is considered a promising radioisotope for diagnosing prostate cancer, as early results have recently shown.

Innovative ideas and technologies from physics have contributed to great advances in the field of medicine over the last 100 years, since the advent of radiation-based medical diagnosis and treatment and following the discovery of X-rays and radioactivity. Radioisotopes are thus already widely used by the medical community for imaging, diagnosis and radiation therapy. However, many isotopes currently used do not combine the most appropriate physical and chemical properties and, in some cases, a different type of radiation could be better suited. MEDICIS can help to look for radioisotopes with the right properties to enhance precision for both imaging and treatment.

“CERN-MEDICIS demonstrates again how CERN technologies can benefit society beyond their use for our fundamental research. With its unique facilities and expertise, CERN is committed to maximising the impact of CERN technologies in our everyday lives,” said CERN’s Director for Accelerators and Technology, Frédérick Bordry.  

At ISOLDE, the high-intensity proton beam from CERN’s Proton Synchrotron Booster (PSB) is directed onto specially developed thick targets, yielding a large variety of atomic fragments. Different devices are used to ionise, extract and separate nuclei according to their mass, forming a low-energy beam that is delivered to various experimental stations. MEDICIS works by placing a second target behind ISOLDE’s. Once the isotopes have been produced at the MEDICIS target, an automated conveyor belt carries them to the MEDICIS facility, where the radioisotopes of interest are extracted through mass separation and implanted in a metallic foil. They are then delivered to research facilities including the Paul Scherrer Institut (PSI), the University Hospital of Vaud (CHUV) and the Geneva University Hospitals (HUG).

Once at the facility, researchers dissolve the isotope and attach it to a molecule, such as a protein or sugar, chosen to target the tumour precisely. This makes the isotope injectable, and the molecule can then adhere to the tumour or organ that needs imaging or treating.

ISOLDE has been running for 50 years, and 1300 isotopes from 73 chemicals have been produced at CERN for research in many areas, including fundamental nuclear research, astrophysics and life sciences. Although ISOLDE already produces isotopes for medical research, the new MEDICIS facility will allow it to provide radioisotopes meeting the requirements of the medical research community as a matter of course.

CERN-MEDICIS is an effort led by CERN with contributions from its dedicated Knowledge Transfer Fund, private foundations and partner institutes. It also benefits from a European Commission Marie Skłodowska-Curie training grant, which has been helping to shape a pan-European medical and scientific collaboration since 2014.

 

The robot arm at MEDICIS. (Video: Noemi Caraban/CERN)

Crab cavities: colliding protons head-on

Fri, 12/08/2017 - 09:59

One of the first two crab cavities during construction in a clean room at CERN. (Image: Ulysse Fichet/CERN)

They won’t pinch you and you won’t find them on the beach. The name of the new radio-frequency crab cavities has nothing to do with their appearance and is merely illustrative of the effect they will have on circulating proton bunches.

Crab cavities will help increase the luminosity of collisions in the High-Luminosity LHC (HL-LHC) – the future upgrade of the LHC planned for after 2025. The luminosity of a collider is proportional to the number of collisions that occur in a given amount of time. The higher the luminosity, the more collisions, and the more data the experiments can gather to allow them to observe rare processes.

At present, two superconducting crab cavities have been manufactured at CERN and inserted into a specially designed cryostat, which will keep them at their operating temperature of two kelvin. Currently in their final stages of testing, they will be installed in the Super Proton Synchrotron (SPS) during this year’s winter technical stop. In 2018, they will be tested with a proton beam for the first time. 

The assembly of the crab cavity housing, a cryostat that will serve as a high-performance thermos flask, reducing the heat load and keeping the cavities at their operating temperature. (Image: Maximilien Brice/CERN)

The beams in the LHC are made of bunches, each containing billions of protons. They are similar to trains with carriages full of billions of passengers. In the LHC, the two counter-circulating proton beams meet at a small crossing angle at the collision point of the experiments.

What makes the crab cavities special is their ability to “tilt” the proton bunches in each beam, maximising their overlap at the collision point. Тhis way every single proton in the bunch is forced to pass through the whole length of the opposite bunch, which increases the probability that it will collide with another particle. After being tilted, the motion of the proton bunches appears to be sideways – just like a crab.

An illustration of the effect of the crab cavities on the proton bunches. (Image: CERN)

Find out more about the crab cavities in the video below.

Rama Calaga, the radio-frequency physicist behind the technology, Ofelia Capatina, deputy leader of the crab cavities project, and Lucio Rossi, leader of the High-Luminosity LHC project, explain the principle of the crab cavities. (Video: Polar Media and CERN Audiovisual Productions)

At the LHC, tomorrow is already here

Tue, 12/05/2017 - 11:24

The CERN Control Centre in 2017, from where all the Laboratory's accelerators and technical infrastructure are controlled. The accelerator complex and the LHC produced a record amount of data in 2017. (Image: Julien Ordan/CERN)

On Monday, 4 December at 4.00 a.m., the accelerator operators hit the stop button on the accelerator complex and the Large Hadron Collider for their usual winter break. But while the machines are hibernating, there’s no rest for the humans, as CERN teams will be busy with all the maintenance and upgrade work required before the machines are restarted in the spring. 

The LHC has ended the year with yet another luminosity record, having produced 50 inverse femtobarns of data, i.e. 5 million billion collisions, in 2017. But the accelerator hasn’t just produced lots of data for the physics programmes. 

Before the technical stop, a number of new techniques for increasing the luminosity of the machine were tested. These techniques are mostly being developed for the LHC’s successor, the High-Luminosity LHC. With a planned start-up date of 2026, the High-Luminosity LHC will produce five to ten times as many collisions as the current LHC. To do this, it will be kitted out with new equipment and will use a new optics scheme, based on ATS (Achromatic Telescopic Squeezing), a configuration that was tested this year at the LHC. 

Handling beams of particles is a bit like handling beams of light. In an accelerator, dipole magnets act like mirrors, guiding the beams around the bends. Quadrupole magnets act alternately like concave or convex lenses, keeping the beams in line transversally, but mainly focusing them as much as possible at the interaction points of the experiments. Corrector magnets (hexapoles) correct chromatic aberrations (a bit like corrective lenses for astigmatism). Configuring the optics of an accelerator is all about combining the strengths of these different magnets.

One particularly efficient approach to increasing luminosity, and therefore the number of collisions, is to reduce the size of the beam at the interaction points, or in other words to compress the bunches of particles as much as possible. In the High-Luminosity LHC, more powerful quadrupole magnets with larger apertures, installed either side of the experiments, will focus the bunches before collision. However, for these magnets to be as effective as possible, the beam must first be considerably expanded: a bit like a stretching a spring as much as possible so that it retracts as much as possible. And this is where the new configuration comes in. Instead of just using the quadrupole magnets either side of the collision points, the ATS system also makes use of magnets situated further away from the experiments in the machine, transforming seven kilometres of the accelerator into a giant focusing system. 

Graph showing the integrated luminosity over the various runs of the LHC. In 2017, the LHC produced 50 inverse femtobarns of data, the equivalent of 5 million billion collisions. (Image: CERN)

These techniques have been used in part this year at the LHC and will be used even more during future runs. “The heart of the High-Luminosity LHC is already beating in the LHC,” explains Stéphane Fartoukh, the physicist who came up with the new concept.  “The latest tests, carried out last week, have once again proved the reliability of the scheme and demonstrated other potential applications, sometimes beyond our initial expectations.

For further information:

How to produce the purest argon ever?

Thu, 11/30/2017 - 16:16

ARIA’s modules are being leak-tested at CERN before travelling to Sardinia, Italy. The top, bottom and one standard column module have now been lined up horizontally to test their alignment. (Image: J. Ordan/CERN)

Producing the purest argon ever made is no mean feat, in fact it needs a column 26 metres taller than the Eiffel Tower.

CERN is part of a project, called ARIA, to construct a 350-metre-tall distillation tower that will be used to purify liquid argon for scientific and, in a second phase, medical use.

The full tower, composed of 28 identical modules plus a top (condenser) and a bottom (re-boiler) special module, will be installed in a disused mine site in Sardinia, Italy.

The project is was initiated to supply the purest argon possible to the international dark matter experiment DarkSide at INFN’s Gran Sasso National Laboratories. DarkSide is a dual-phase liquid-argon time-projection chamber that aims to detect the possible passage of a dark matter particle in the form of a Weakly Interacting Massive Particle (WIMP) when it hits the argon nuclei contained in the detector. Since this WIMP-nuclei interaction is predicted to be extremely rare, the detector must contain only the purest argon possible, so as not to accidentally produce a spurious signal.

ARIA has been designed to produce this extra-pure argon. Atmospheric argon contains many “impurities” such as water, oxygen, krypton and argon-39, an isotope of argon, which are all sources of unwanted signals. Argon from underground sources is already depleted from the argon-39 isotope by a factor of 1400, but this is still not enough for dark-matter research. ARIA is designed to purify underground argon by a further factor of 100.

For more information, read this article.

A very special run for the LHCb experiment

Thu, 11/30/2017 - 09:19

The LHCb detector in open configuration. (Image: Anna Pantelia/CERN)

For the first time, the LHCb experiment at CERN has collected data simultaneously in collider and in fixed-target modes. With this, the LHCb special run is even more special.

The past two weeks have been devoted to special runs of the Large Hadron Collider (LHC), at the end of the LHC 2017 proton run and before the winter shutdown. One run involved proton collisions at an energy of 5.02 TeV, mainly to set a reference to compare with lead-ion collision data. What was exceptional this year is that a tiny quantity of neon gas was injected into the beam pipe near the LHCb experiment’s interaction point. This allowed physicists to collect proton-neon at the same time as proton-proton collision data.

When (noble) gases are injected into the beam pipe to collide with protons, the LHCb experiment is in “fixed-target” mode, in contrast to the standard “collider” mode. But unlike traditional fixed target experiments, where the beam of accelerated particles is directed at a dense solid or liquid target, here LHC protons are colliding with a handful of neon nuclei injected near the collision point and floating in the beam pipe. These nuclei slightly pollute the almost perfect LHC vacuum, but the conditions they create – where pressure is in the order of 10-7 millibar – are still considered to be typical of ultra-high vacuum environments.

There are two main reasons to collect proton-gas collision data at the LHC. On one hand, these data help understand nuclear effects (i.e. depending on the type of nuclei involved in the collisions), affecting the production of specific types of particles (J/ψ and D0 mesons), whose suppressed production is considered to be the hallmark of the quark-gluon plasma. The quark-gluon plasma is the state in which the matter filling the universe a few millionths of a second after the Big Bang was , when protons and neutrons had not yet formed, composed of quarks not binding together and then free to move on their own.  

On the other hand, proton-neon interactions are important to also study cosmic rays – highly energetic particles, mostly protons, coming from outside the Solar System – when they collide with nuclei in the Earth’s atmosphere. Neon is one of the components of the Earth’s atmosphere and it is very similar in terms of nuclear size to the much more abundant nitrogen and oxygen.

This gas-injection technique was originally designed to measure the brightness of the accelerator's beams, but its potential was quickly recognised by the LHCb physicists and it is now also being used for dedicated physics measurements. In 2015 and 2016, the LHCb experiment already performed special proton-helium, proton-neon and proton-argon runs. In October this year, for eight hours only, the LHC accelerated and collided xenon nuclei, allowing the four large LHC experiments to record xenon-xenon collisions for the first time.

This recent 11-day proton-neon run will allow physicists to collect a dataset that is 100 times larger than all proton-neon collision data collected until now at the LHC, and the first results of the analyses are foreseen for next year.

Find out more on the LHCb website

AWAKE: Closer to a breakthrough acceleration technology

Fri, 11/24/2017 - 15:48

The electron source and electron beam line of AWAKE have just been installed. (Image: Maximilien Brice, Julien Ordan/CERN)

We are one step closer to testing a breakthrough technology for particle acceleration. The final three key parts of AWAKE have just been put in place: its electron source, electron beam line and electron spectrometer. This marks the end of the installation phase of the Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE), a proof-of-principle experiment at CERN that is developing a new technique for accelerating particles.

The accelerators currently in use rely on electric fields generated by radiofrequency (RF) cavities to accelerate charged particles by giving them a “kick”. In AWAKE, a beam of electrons will “surf” waves of electric charges, or wakefields. These waves are created when a beam of protons is injected into the heart of AWAKE, a 10-metre plasma cell full of ionised gas. When the protons travel through the plasma, they attract free electrons, which generate wakefields. A second particle beam, this time of electrons, is injected into the right phase behind the proton beam. As a result, it feels the wakefield and is accelerated, just like a surfer riding a wave.

After exiting the plasma cell, the electrons will pass through a dipole magnet, which will curve their path. More energetic particles will get a smaller curvature. As well as the electron beam line, another new component is the scintillator that awaits the electrons at the end of the dipole, showing whether or not they have been accelerated. Essentially, this is a screen that lights up whenever a charged particle passes through it. Successfully accelerated electrons will be bent to a lesser degree by the magnetic field and will appear on one side of the scintillator.

Ans Pardons, integration and installation coordinator of AWAKE, beside the one-metre-wide scintillator. (Image: Maximilien Brice, Julien Ordan/CERN)

From now until the end of 2017, the whole AWAKE experiment, including the electron source and the electron beam line, will be being commissioned and prepared for a very important year ahead. “It is very important to first create a high-quality electron beam with the correct energy and intensity, and then to successfully send it through the electron beam line and the plasma cell,” explains Ans Pardons, integration and installation coordinator of AWAKE.

The first milestone was reached in December 2016, when the first data showed that the wakefields had been successfully generated. After a very successful 2017 run, it is now time for AWAKE’s next big step. Next year will be fully dedicated to proving that the acceleration of electrons in the wake of proton bunches is possible.

AWAKE's new electron line (Image: Maximilien Brice, Julien Ordan)

AWAKE: Closer to a breakthrough acceleration technology

Fri, 11/24/2017 - 15:48

The electron source and electron beam line of AWAKE have just been installed. (Image: Maximilien Brice, Julien Ordan/CERN)

We are one step closer to testing a breakthrough technology for particle acceleration. The final three key parts of AWAKE have just been put in place: its electron source, electron beam line and electron spectrometer. This marks the end of the installation phase of the Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE), a proof-of-principle experiment at CERN that is developing a new technique for accelerating particles.

The accelerators currently in use rely on electric fields generated by radiofrequency (RF) cavities to accelerate charged particles by giving them a “kick”. In AWAKE, a beam of electrons will “surf” waves of electric charges, or wakefields. These waves are created when a beam of protons is injected into the heart of AWAKE, a 10-metre plasma cell full of ionised gas. When the protons travel through the plasma, they attract free electrons, which generate wakefields. A second particle beam, this time of electrons, is injected into the right phase behind the proton beam. As a result, it feels the wakefield and is accelerated, just like a surfer riding a wave.

After exiting the plasma cell, the electrons will pass through a dipole magnet, which will curve their path. More energetic particles will get a smaller curvature. As well as the electron beam line, another new component is the scintillator that awaits the electrons at the end of the dipole, showing whether or not they have been accelerated. Essentially, this is a screen that lights up whenever a charged particle passes through it. Successfully accelerated electrons will be bent to a lesser degree by the magnetic field and will appear on one side of the scintillator.

Ans Pardons, integration and installation coordinator of AWAKE, beside the one-metre-wide scintillator. (Image: Maximilien Brice, Julien Ordan/CERN)

From now until the end of 2017, the whole AWAKE experiment, including the electron source and the electron beam line, will be being commissioned and prepared for a very important year ahead. “It is very important to first create a high-quality electron beam with the correct energy and intensity, and then to successfully send it through the electron beam line and the plasma cell,” explains Ans Pardons, integration and installation coordinator of AWAKE.

The first milestone was reached in December 2016, when the first data showed that the wakefields had been successfully generated. After a very successful 2017 run, it is now time for AWAKE’s next big step. Next year will be fully dedicated to proving that the acceleration of electrons in the wake of proton bunches is possible.

AWAKE's new electron line (Image: Maximilien Brice, Julien Ordan)

First light for pioneering SESAME light source

Thu, 11/23/2017 - 11:07

SESAME XAFS/XRF beamline scientist, Messaoud Harfouche, points out SESAME’s first monochromatic light. (Image: SESAME)

At 10:50 yesterday morning scientists at the pioneering SESAME light source saw First Monochromatic Light through the XAFS/XRF (X-ray absorption fine structure/X-ray fluorescence) spectroscopy beamline, signalling the start of the laboratory’s experimental programme. This beamline, SESAME’s first to come on stream, delivers X-ray light that will be used to carry out research in areas ranging from solid state physics to environmental science and archaeology.

“After years of preparation, it’s great to see light on target,” said XAFS/XRF beamline scientist Messaoud Harfouche. “We have a fantastic experimental programme ahead of us, starting with an experiment to investigate heavy metals contaminating soils in the region.”

The initial research programme will be carried out at two beamlines, the XAFS/XRF beamline and the Infrared (IR) spectromicroscopy beamline that is scheduled to join the XAFS/XRF beamline this year. Both have specific characteristics that make them appropriate for various areas of research. A third beamline, devoted to materials science, will come on stream in 2018.


Inside SESAME's ring (Image: Noemi Caraban/CERN)

“Our first three beamlines already give SESAME a wide range of research options to fulfil the needs of our research community,” said SESAME Scientific Director Giorgio Paolucci, “the future for light source research in the Middle East and neighbouring countries is looking very bright!”

First Light is an important step in the commissioning process of a new synchrotron light source, but it is nevertheless just one step on the way to full operation. The SESAME synchrotron is currently operating with a beam current of just over 80 milliamps, while the design value is 400 milliamps. Over the coming weeks and months as experiments get underway, the current will be gradually increased.

“SESAME is a major scientific and technological addition to research and education in the Middle East and beyond,” said Director of SESAME, Khaled Toukan. “Jordan supported the project financially and politically since its inception in 2004 for the benefit of science and peace in the region. The young scientists, physicists, engineers and administrators who have built SESAME, come for the first time from this part of the world.”

Among the subjects likely to be studied in early experiments are environmental pollution with a view to improving public health, as well as studies aimed at identifying new drugs for cancer therapy, and cultural heritage studies ranging from bioarcheology – the study of our ancestors – to investigations of ancient manuscripts.

“On behalf of the SESAME Council, I’d like to congratulate the SESAME staff on this wonderful milestone,” said President of the Council, Rolf Heuer. “SESAME is a great addition to the region’s research infrastructure, allowing scientists from the region access to the kind of facility that they previously had to travel to Europe or the US to use.”

 

 

 

First light for pioneering SESAME light source

Thu, 11/23/2017 - 11:07

SESAME XAFS/XRF beamline scientist, Messaoud Harfouche, points out SESAME’s first monochromatic light. (Image: SESAME)

At 10:50 yesterday morning scientists at the pioneering SESAME light source saw First Monochromatic Light through the XAFS/XRF (X-ray absorption fine structure/X-ray fluorescence) spectroscopy beamline, signalling the start of the laboratory’s experimental programme. This beamline, SESAME’s first to come on stream, delivers X-ray light that will be used to carry out research in areas ranging from solid state physics to environmental science and archaeology.

“After years of preparation, it’s great to see light on target,” said XAFS/XRF beamline scientist Messaoud Harfouche. “We have a fantastic experimental programme ahead of us, starting with an experiment to investigate heavy metals contaminating soils in the region.”

The initial research programme will be carried out at two beamlines, the XAFS/XRF beamline and the Infrared (IR) spectromicroscopy beamline that is scheduled to join the XAFS/XRF beamline this year. Both have specific characteristics that make them appropriate for various areas of research. A third beamline, devoted to materials science, will come on stream in 2018.


Inside SESAME's ring (Image: Noemi Caraban/CERN)

“Our first three beamlines already give SESAME a wide range of research options to fulfil the needs of our research community,” said SESAME Scientific Director Giorgio Paolucci, “the future for light source research in the Middle East and neighbouring countries is looking very bright!”

First Light is an important step in the commissioning process of a new synchrotron light source, but it is nevertheless just one step on the way to full operation. The SESAME synchrotron is currently operating with a beam current of just over 80 milliamps, while the design value is 400 milliamps. Over the coming weeks and months as experiments get underway, the current will be gradually increased.

“SESAME is a major scientific and technological addition to research and education in the Middle East and beyond,” said Director of SESAME, Khaled Toukan. “Jordan supported the project financially and politically since its inception in 2004 for the benefit of science and peace in the region. The young scientists, physicists, engineers and administrators who have built SESAME, come for the first time from this part of the world.”

Among the subjects likely to be studied in early experiments are environmental pollution with a view to improving public health, as well as studies aimed at identifying new drugs for cancer therapy, and cultural heritage studies ranging from bioarcheology – the study of our ancestors – to investigations of ancient manuscripts.

“On behalf of the SESAME Council, I’d like to congratulate the SESAME staff on this wonderful milestone,” said President of the Council, Rolf Heuer. “SESAME is a great addition to the region’s research infrastructure, allowing scientists from the region access to the kind of facility that they previously had to travel to Europe or the US to use.”

 

 

 

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