CERN Accelerating science

Proton Synchrotron prepared for higher injection energies

The new kicker for the PS being installed in the accelerator (Image: Julien Ordan/CERN)

 

Proton beams entering the Proton Synchrotron (PS) from the PS Booster have to be deflected into a circulating orbit before they can be accelerated. This is done by two specialised beam-line elements: a strong magnetic septum and a fast injection-kicker magnet. The latter is a precisely synchronised electromagnet that can be switched on and off in about 100 ns, providing a stable and uniform kick that only affects the injected beam batches, while leaving the already circulating beam unperturbed.

After the ongoing second long shutdown of CERN’s accelerator complex (LS2), the PS Booster will accelerate particles to 2 GeV, almost 50% higher than the pre-LS2 value of 1.4 GeV. The PS therefore needed a new septum and a new kicker capable of coping with this increased injection energy. On 31 January, as part of the LHC Injectors Upgrade (LIU) project, the new kicker magnet was installed, replacing the kicker that had operated since 1979. The magnet will soon be aligned, connected to the vacuum system and then connected to the power and control cables.

Like the magnet it replaced, the PS’s new kicker is made of four identical modules sitting in a 1-metre-long vacuum tank. Each module receives power from a separate pulse generator that consists of two high-power electrical switches – a main switch and a dump switch to control the pulse length – and around 280 metres of a so-called “pulse-forming line”, wound and stored on gigantic drums. These lines are thick, coaxial cables filled with sulphur hexafluoride (SF6) at a pressure of 10 bars, to provide the necessary insulation for the charging voltage of 80 kV. Since SF6 is a strong greenhouse gas, special care has to be taken to ensure that it is safely manipulated and recuperated, and that the system has no leaks.

In order to reduce the dependence on the SF6-based cables, part of the transmission line between the pulse generator and the magnet was replaced with conventional cables. “Disconnecting the SF6 cables from the magnet to connect the reserves was a two-person job, and required time-consuming gas-handling procedures to be followed,” explains Thomas Kramer from the TE-ABT (Accelerator Beam Transfer) group. “On the other hand, the new conventional cables have quick-release connectors and can be operated by one person fairly quickly.”

Kramer and colleagues also replaced the old analogue control system for the kicker, parts of which had been in place since the system was constructed in the 1970s. “Things made back then still work reliably,” smiles Kramer, while noting that the new digital systems make it possible to monitor the situation remotely.

One element that remains to be installed is the new septum. This is a delicate device used in the injection system, composed of two cavities separated by a thin wall: one cavity allows the beams from the PS Booster to enter the PS while the second is meant for the circulating beams. The new septum, which required construction of a novel power converter, will be installed upstream of the magnet in the coming weeks.

This news first appeared at home.cern

Shane Koscielniak (TRIUMF), Tor Raubenheimer (SLAC)
IPAC 18: Vancouver welcomes the world of accelerator physics!
28 Jun 2018

IPAC 18: Vancouver welcomes the world of accelerator physics!

IPAC18 brought together accelerator scientists and industrial vendors from across the globe to share ideas on the cutting edge of accelerator science and technology.

L. Bottura, A. Devred, S. Izquierdo Bermudez, J.C. Perez and D. Tommasini (CERN)
Demonstrator racetrack dipole magnet produces record peak field
25 Mar 2020

Demonstrator racetrack dipole magnet produces record peak field

A magnetic field record has been broken at CERN by the first racetrack demonstrator magnet developed in the framework of the FCC Study.

Mike Barnes (CERN)
First workshop on Pulse Power for Kicker Systems held at CERN
28 Jun 2018

First workshop on Pulse Power for Kicker Systems held at CERN

The PULPOKS 2018 workshop brought more than 40 participants to discuss the latest developments in the field of pulsed power for particle accelerators

HL-LHC superconducting quadrupole successfully tested

The quadrupole magnet being prepared for a test at Brookhaven National Laboratory. (Image: Brookhaven National Laboratory)

 

A quadrupole magnet for the high-luminosity LHC (HL-LHC) has been tested successfully in the US, attaining a conductor peak field of 11.4 T – a record for a focusing magnet ready for installation in an accelerator. The 4.2 m-long, 150-mm-single-aperture device is based on the superconductor niobium tin (Nb3Sn) and is one of several quadrupoles being built by US labs and CERN for the HL-LHC, where they will squeeze the proton beams more tightly within the ATLAS and CMS experiments to produce a higher luminosity. The result follows successful tests carried out last year at CERN of the first accelerator-ready Nb3Sn dipole magnet, and both of these milestones are soon to be followed by tests of other 7.2 m and 4.2 m quadrupole magnets at CERN and the US.

“This copious harvest comes after significant recent R&D on niobium-tin superconducting magnet technology and is the best answer to the question if HL-LHC is on time: it is,” says HL-LHC project leader Lucio Rossi of CERN. “We should also underline that this full-length, accelerator-ready magnet performance record is a real textbook case for international collaboration in the accelerator domain: since the very beginning the three US labs and CERN teamed up and managed to have a common and very synergic R&D, particularly for the quadrupole magnet that is the cornerstone of the upgrade. This has resulted in substantial savings and improved output.”

The current LHC magnets, which have been tested to a bore field of 8.3 T and are currently operated at 7.7 T at 1.9 K for 6.5 TeV operation, are made from the superconductor niobium-titanium (Nb-Ti). As the transport properties of Nb-Ti are limited for fields beyond 10-11 T at 1.9 K, HL-LHC magnets call for a move to Nb3Sn, which remain superconducting for much higher fields. Although Nb3Sn has been studied for decades and is already in widespread use in solenoids for NMR — not to mention underpinning the large coils, presently being manufactured, that will be used to contain and control the plasma in the ITER fusion experiment – it is more challenging than Nb-Ti to work with: once formed, the Nb3Sn compound becomes brittle and strain sensitive and therefore much harder than niobium-titanium alloy to process into cables to be wound with the accuracy required to achieve the performance and field quality of state-of-the-art accelerator magnets.

Researchers at Fermilab, Brookhaven National Laboratory and Lawrence Berkeley National Laboratory are to provide a total of 16 quadrupole magnets for the interactions regions of the HL-LHC, which is due to operate from 2027. The purpose of a quadrupole magnet is to produce a field gradient in the radial direction with respect to the beam, allowing charged-particle beams to be focused. A test was carried out at Brookhaven in January, when the team operated the 8-tonne quadrupole magnet continuously at a nominal field gradient of around 130 T/m and a temperature of 1.9 K for five hours. Eight longer quadrupole magnets (each providing an equivalent “cold mass” as two US quadrupole magnets) are being produced by CERN.

“We’ve demonstrated that this first quadrupole magnet behaves successfully and according to design, based on the multiyear development effort made possible by DOE investments in this new technology,” said Fermilab’s Giorgio Apollinari, head of the US Accelerator Upgrade Project in a Fermilab press release. “It’s a very cutting-edge magnet,” added Kathleen Amm, who is Brookhaven’s representative for the project.

Dipole tests at CERN

In addition to stronger focusing magnets, the HL-LHC requires new dipole magnets positioned on either side of a collimator to correct off-momentum protons in the high-intensity beam. To gain the required space in the magnetic lattice, Nb3Sn dipole magnets of shorter length and higher field than the current LHC dipole magnets are needed. In July 2019 the CERN magnet group successfully tested a full-length, 5.3-m, 60-mm-twin-aperture dipole magnet – the longest Nb3Sn magnet tested so far – and achieved a nominal bore field of 11.2 T at 1.9 K (corresponding to a conductor peak field of 11.8 T).

“This multi-year effort on Nb3Sn, which we are running together with the US, and our partner laboratories in Europe, is leading to a major breakthrough in accelerator magnet technology, from which CERN, and the whole particle physics community, will profit for the years to come,” says Luca Bottura, head of the CERN magnet group.

The dipole- and quadrupole-magnet milestones also send a positive signal about the viability of future hadron colliders beyond the LHC, which are expected to rely on Nb3Sn magnets with fields of up to 16 T. To this end, CERN and the US labs are achieving impressive results in the performance of Nb3Sn conductor in various demonstrator magnets. In February, the CERN magnet group produced a record field of 16.36 T at 1.9 K (16.5 T conductor peak field) in the centre of a short “enhanced racetrack model coil” demonstrator, with no useful aperture, which was developed in the framework of the Future Circular Collider study. In June 2019, as part of the US Magnet Development Programme, a short “cos-theta” dipole magnet with an aperture of 60 mm reached a bore field of 14.1 T at 4.5 K at Fermilab. Beyond magnets, says Rossi, the HL-LHC is also breaking new ground in superconducting-RF crab cavities, advanced material collimators and 120 kA links based on novel MgB2 superconductors.

Next steps

Before they can constitute fully operational accelerator magnets which could be installed in the HL-LHC, both these quadrupole magnets and the dipole magnets must be connected in pairs (the longer CERN quadrupole magnets are single units). Each magnet in a pair has the same winding, and differs only in its mechanical interfaces and details of its electrical circuitry. Tests of the remaining halves of the quadrupole- and dipole-magnet pairs were scheduled to take place in the US and at CERN during the coming months, with the dipole magnet pairs to be installed in the LHC tunnel this year. Given the current global situation, this plan will have to be reviewed, which is now the high-priority discussion within the HL-LHC project.

This news appeared first at the CERN Courier

This news was also featured at Fermilab

Livia Lapadatescu
Simon van der Meer Award
24 Mar 2019

Simon van der Meer Award

Apply now to Simon van der Meer Early Career Award in Novel Accelerators! Deadline: 27 May 2019

Philippe Lebrun, JUAS Director
25th edition of Joint Universities Accelerator School
13 Mar 2018

25th edition of Joint Universities Accelerator School

Twenty-five years of training accelerator scientists and going from strength to strength

Panos Charitos (CERN)
EASITrain gears up following mid-term review
12 Dec 2018

EASITrain gears up following mid-term review

The meeting offered the opportunity to young researchers to present their latest work.

Synchrotrons on the frontline

Representation of the 3D structure of the main SARS-CoV-2 protease, obtained using Diamond Light Source. The coils represent “alpha” helices and the flatter arrows are “beta sheets”, with loops connecting them together. The organisation of alpha helices and beta sheets is often referred to as the secondary structure of the protein (with the primary sequence being the amino acid sequence and the tertiary structure being the overall 3D shape of the protein). (Image: D Owen/Diamond Light Source.)

 

At a time when many countries are locking down borders, limiting public gatherings, and encouraging isolation, the Diamond Light Source in Oxfordshire, UK, has been ramping up its intensity, albeit in an organised and controlled manner. The reason: these scientists are working tirelessly on drug-discovery efforts to quell COVID-19.

It is a story that requires fast detectors, reliable robotics and powerful computing infrastructures, artificial intelligence, and one of the brightest X-ray sources in the world. And it is made possible by international collaboration, dedication, determination and perseverance.

Synchrotron light sources are particle accelerators capable of producing incredibly bright X-rays, by forcing relativistic electrons to accelerate on curved trajectories. Around 50 facilities exist worldwide, enabling studies over a vast range of topics. Fanning out tangentially from Diamond’s 562-m circumference storage ring are more than 30 beamlines equipped with instrumentation to serve a multitude of user experiments. The intensely bright X-rays (corresponding to flux of around 9 × 1012 photons per second) are necessary for determining the atomic structure of proteins, including the proteins which make up viruses. As such, synchrotron light sources around the world are interrupting their usual operations to work on mapping the structure of the SARS-CoV-2 virus.

Knowing the atomic structure of the virus is like knowing how the enemy thinks. A 3D visualisation of the building blocks of the structure at an atomic level would allow scientists to understand how the virus functions. Enzymes, the molecular machines that allow the virus to replicate, are key to this process. Scientists at Diamond are exploring the binding site of the main SARS-CoV-2 protease. A drug that binds to this enzyme’s active site would throw a chemical spanner in the works, blocking the virus’ ability to replicate and limiting the spread of the disease.

By way of reminder: Coronavirus is the family of viruses responsible for the common cold, MERS, SARS, etc. Novel coronavirus, aka SARS-CoV-2, is the newly discovered type of coronavirus, and COVID-19 is the disease which it causes.

Call to arms

On 26 January, Diamond’s life-sciences director, Dave Stuart, received a phone call from structural biologist Zihe Rao of ShanghaiTech University in China. Rao, along with his colleague Haitao Yang, had solved the structure of the main SARS-CoV-2 protease with a covalent inhibitor using the Shanghai Synchrotron Radiation Facility (SSRF) in China. Furthermore, they had made the solution freely and publicly available on the worldwide Protein Data Bank.

During the phone call, Rao informed Stuart that their work had been halted by a scheduled shutdown of the SSRF. The Diamond team rapidly mobilised. Since shipping biological samples from Shanghai at the height of the coronavirus in China was expected to be problematic, the team at Diamond ordered the synthetic gene. A synthetic gene can be generated provided the ordering of T, A, C and G nucleotides in the DNA sequence is known. That synthetic gene can be genetically engineered into a bacterium, in this case Escherichia. coli, which reads the sequence and generates the coronavirus protease in large enough quantities for the researchers at Diamond to determine its structure and screen for potential inhibitors.

Eleven days later on 10 February, the synthetic gene arrived. At this point, Martin Walsh, Diamond’s deputy director of life sciences, and his team (consisting of Claire Strain-Damerell, Petra Lukacik, and David Owen) dropped everything. With the gene in hand, the group immediately set up experimental trials to try to generate protein crystals. In order to determine the atomic structure, they needed a crystal containing millions of proteins in an ordered grid-like structure.

Diamond Light Source, the UK

Diamond Light Source, the UK’s national synchrotron facility, located at the Harwell Science and Innovation Campus in Oxfordshire. (Image: Diamond Light Source.)

X-ray radiation bright enough for the rapid analysis of protein structures can only be produced by a synchrotron light source. The X-rays are directed and focused down a beamline onto a crystal and, as they pass through it, they diffract. From the diffraction pattern, researchers can work backwards to determine the 3D electron density maps and the structure of the protein. The result is a complex curled ribbon-like structure with an intricate mess of twists and turns of the protein chain.

The Diamond team set up numerous trials trying to find the optimum conditions for crystallization of the SARS-CoV-2 protease to occur. They modified the pH, the precipitating compounds, chemical composition, protein to solution ratio… every parameter they could vary, they did. Every day they would produce a few thousand trials, of which only a few hundred would produce crystals, and even fewer would produce crystals of sufficient quality. Within a few days of receiving the gene, the first crystals were being produced. They were paltry and thin crystals but large enough to be tested on one of Diamond’s macromolecular crystallography beamlines.

Watching the results come through, Diamond postdoc David Owen described it as the first moment of intense excitement. With crystals that appeared to be “flat like a car wind shield,” he was dubious as to whether they would diffract at all. Nevertheless, the team placed the crystals in the beamline with a resignation that quickly turned into intense curiosity as the results started appearing before them. At that moment Owen remembers his doubts fading, as he thought, “this might just work!” And work it did. In fact, Owen recalls, “they diffracted beautifully.” These first diffraction patterns of the SARS-CoV-2 virus were recorded with a resolution of 1.9 Angstrom (1.9 × 10−10 m) — high enough resolution to see the position of all of the chemical groups that allow the protease to do its work.

By 19 February, through constant adjustments and learning, the team knew they could grow good-quality crystals quickly. It was time to bring in more colleagues. The XChem team at Diamond joined the mission to set up fragment-based screening – whereby a vast library of small molecules (“fragments”) are soaked into crystals of the viral protease. These fragments are significantly smaller and functionally simpler than most drug molecules and are a powerful approach to selecting candidates for early drug discovery. By 26 February, 600 crystals had been mounted and the first fragment screen launched. In parallel, the team had been making a series of sample to send to company in Oxford called Exscientia, which has set up an AI platform designed to expediate candidates in drug discovery.

Drug-discovery potential

As of early March, 1500 crystals and fragments have been analysed. Owen attributes the team’s success so far to the incredible amounts of data they could collect and analyse quickly. With huge numbers of data sets, they could pin down the parameters of the viral protease with a high degree of confidence. And with the synchrotron light source they were able to create and analyse the diffraction patterns rapidly. The same amount of data collected with a lab-based X-ray source would have taken approximately 10 years. At Diamond, they were able to collect the data in a few days of accumulated beamtime.

Synchrotron light sources all over the world have been granting priority and rapid access to researchers to support their efforts in discovering more about the virus. Researchers at the Advanced Photon Source in Argonne, US, and at Elettra Sincrotrone in Trieste, Italy are also trying to identify molecules effective against COVID-19, in an attempt to bring us closer to an effective vaccine or treatment. This week, the ESRF in Grenoble, France, announced that it will make its cryo-electron microscope facility available for use. The community has a platform called www.lightsources.org offering an overview of access and calls for proposals.

In addition to allowing the structure of tens of thousands of biological structures to be elucidated – such as that of the ribosome, which was recognised by the 2009 Nobel Prize in Chemistry — light sources have a strong pedigree in elucidating the structure of viruses. Development of common anti-viral medication that blocks the actions of virus in the body, such as Tamiflu or Relenza, also relied upon synchrotrons to reveal their atomic structure.

Mapping the SARS-CoV-2 protease structures bound to small chemical fragments, the Diamond team demonstrated a crystallography- and fragmentation-screen tour de force. The resulting and ongoing work is a crucial first step in developing a drug. Forgoing the usual academic root of peer-review, the Diamond team have made all of their results openly and freely available to help inform public heath response, limit the spread of the virus with the hope that this can fast-track effective treatment options.

This news first appeared on the CERN Courier

Isabel Bejar Alonso (CERN) , Panagiotis Charitos (CERN)
A bright future for HL-LHC
7 Dec 2017

A bright future for HL-LHC

The 7th HL-LHC annual collaboration meeting in Madrid reviewed the current progress and set the goals for next year.

Federico Carra (CERN)
A novel composite for HL-LHC collimators
12 Jul 2019

A novel composite for HL-LHC collimators

During the LS2, the LHC collimation system will be upgraded with new primary collimators for halo cleaning and in the dispersion suppression region.

Stéphanie Vandergooten
Apply now to the Joint Universities Accelerator School
23 Sep 2019

Apply now to the Joint Universities Accelerator School

Interested to learn more about Particle Accelerators? Apply now to the 2020 JUAS School in Archamps to follow 5-week courses on particle accelerators.

Game-changing plasma accelerator

Ultra-compact, powerful particle accelerators for research, healthcare, and industry have come a step closer with the completion of the EuPRAXIA design study, showing that plasma acceleration provides a viable alternative to established accelerator technologies.

Currently, the size and cost of accelerator facilities restrict access to this powerful technology, as EuPRAXIA Coordinator Dr. Ralph Assmann from DESY in Germany explains:

“In addition to their important role in fundamental research, particle accelerators are used throughout medicine and industry for cancer therapy, the production of radioisotopes for medical diagnostics, for cargo inspection, food sterilization, and for facilitating advances in the electronics industry. However, the energy achievable with the existing technology is limited by the physical size of the accelerator. Few organisations have the space or budget for a high-energy accelerator because of the size and cost.”

The accelerator designed by EuPRAXIA will use lasers or electron beams to propel electrons forward on a plasma wave. The result will be a much smaller, affordable accelerator that uses accelerating gradients up to 1,000 times higher than what can be achieved with RF technology.


Simulation of a plasma wakefield with ALaDyn PIC code. (Image credit A. Marocchino, INFN-LNF)

Professor Carsten P Welsch, EuPRAXIA’s Communication Lead and Head of Physics at The University of Liverpool, continues: “EuPRAXIA is a game-changer with the potential to offer accelerators for everyone, everywhere. It can make existing applications more accessible and affordable so that future accelerators could be installed in university campuses, hospitals, and factories and offer the opportunity for new applications that we can currently only dream about.”

The design of EuPRAXIA includes a facility for pilot users so that researchers can explore the full potential of the accelerator for the first time. The foreseen electron energy range of 1-5 GeV and its performance goals will enable versatile applications in various domains, e.g. as a compact free-electron laser (FEL), compact sources for positron generation, table-top test beams for particle detectors, as well as deeply penetrating X-ray and gamma-ray sources for material testing. An area of particular interest is to be able to produce ultra-fast electron and photon pulses that are highly relevant for studying biological and chemical processes.

Over the last four years, scientists have evaluated nine different scenarios for creating high-quality beams using plasma acceleration. In the end, several highly performing accelerator designs have been found as an optimal way forward and will be integrated into multiple beamlines using laser- and electron-beam-driven plasma wakefield acceleration.

Once a factor-3 reduction in facility size has been demonstrated by EuPRAXIA, a miniaturization process towards even more compact designs will be pursued. A reduction factor of 10 and even 20 for the accelerator itself seems feasible at high beam energy. 


Rendering of the two-stage, very low energy spread plasma accelerator developed for the EuPRAXIA facility. The open tubes show the paths of the laser pulses (red lines) that drive the plasma wakefields in the vacuum chambers. (Image credit: EuPRAXIA)

The EuPRAXIA design is the result of four years of work by leading scientists from 16 laboratories and universities from five European countries, with a further 25 partners globally. It has been coordinated by DESY and funded by the EU’s Horizon 2020 programme. Participation in EuPRAXIA provides a unique opportunity to be at the forefront of research, which will revolutionise the use of accelerators.

The publication of the conceptual design report is an important milestone towards the realisation of the world’s first plasma accelerator with superior beam quality. Dr. Assmann explains: “EuPRAXIA has involved, amongst others, the international laser community and industry to build links and bridges with accelerator science. The proposed EuPRAXIA infrastructure aims at the construction of an innovative electron accelerator using laser- and electron-beam-driven plasma wakefield acceleration that offers a significant reduction in size and possible savings in cost over current state-of-the-art RF-based accelerators. Our CDR presents a fascinating concept for a next-generation facility.”

More information about EuPRAXIA and the Conceptual Design Report can be found on the project website: http://www.eupraxia-project.eu.

Isabel Bejar Alonso (CERN)
QUACO Phase-3 starts now
10 Dec 2018

QUACO Phase-3 starts now

Following the competitive tender for phase-3, only two solutions could be awarded a work order. Three were evaluated and considered promising.

Ricardo Torres and Alexandra Welsch (University of Liverpool)
Accelerators for Science and Society
11 Jul 2019

Accelerators for Science and Society

International event in Liverpool showcases benefits of accelerator R&D and engages the next generation of researchers.

Athena Papageorgiou Koufidou, Livia Lapadatescu (CERN)
HIE-ISOLDE: challenges and future plans
15 Dec 2017

HIE-ISOLDE: challenges and future plans

HIE-ISOLDE advances the high energy frontier of the facility.

EASISchool Grenoble

Cryogenics and its applications took central stage during the EASISchool 2 that was held from the 30th of September to the 4th of October in two CEA sites, Paris-Saclay and Grenoble, France. Advancements in cryogenic technology has handed scientists and engineers the unique tools paving new ways in our study of the Universe but also finding applications that have revolutionized our way of living. Today, cryogenics finds its application in almost all modern accelerators for research in particle physics and in a broad range of domains including medical instruments, rocket and satellite science, electronics,  manufacturing and food industry among others.

EASISchool 2 offered an intensive training program for the early-stage career researchers, following last year’s EASITrain’s summer school on superconductivity. The school provided training at doctoral level for about 40 students and researchers from all over the world. This is what really happened during the EASISchool autumn school. The scientific and technical topics of the school were selected to give the students the capacity to use, develop, and design the cryogenic instruments, needed for both research and industrial applications. The school focused on open R&D topics that offer the opportunity for collaboration between the academia and the industry while offering to EASITrain early-stage researchers a broad exposure to several companies.

The first day was devoted to cryogenics in the medical instruments, Magnetic Resonance Imaging (MRI) and proton-therapy, and to accelerator applications with presentations from experts on the challenges for superconducting magnets, and RF cavities. Speakers from CEA-Saclay, Varian Medical Systems, ZANON, Institut de Physique Nucléaire d’Orsay, and Research Instruments presented a broad spectrum of applications and lessons learned in the field. The importance of cryogenics for superconducting magnets not limited to particle physics was in the main focus during the second day. The increase of energy in accelerators over the past decades has led to challenging design of superconducting magnets for both accelerators and the associated detectors with LHC pushing accelerator magnet technology to its limits Superconducting magnets are under construction for the International Thermonuclear Experimental Reactor Programme (ITER) built in Cadarache, France. In both cases cryogenics is essential to reach the desired operating temperatures and maximize the performance of these machines. Moreover, ongoing R&D on high-temperature superconductivity, pulsating heat pipe, LNG transport (Gaztransport & Technigaz), and levitation were discussed. Finally, more innovative applications of cryogenics; from quantum computation (Oxford Instruments) to deep-space missions were covered on the afternoon of the second day. The visits of the world-largest MRI magnet (11.7T) at the Neuro-science laboratory and of the accelerator and cryo-magnetism laboratories at CEA-Saclay perfectly illustrated the school lectures.

The world-largest MRI magnet in its final location at the Neurospin laboratory, CEA Paris-Saclay

In the following days in Grenoble, EASISchool 2 took a deeper look into the space and aerospace applications of cryogenics with presentations from ESA, CEA-Grenoble, CNRS, Absolut System, and Air Liquide on different technologies developed to tackle the specific challenges of the space missions. The Planck mission that offered in 2013 the most precise map of the Cosmic Microwave Background radiation, and the MeteoSat satellite were two of the examples discussed during the sessions. The discussion continued in the afternoon with presentations from Air Liquide, Thales Alenia Space, and Ariane Group. Finally, the school covered large-scale cryogenic refrigeration and liquefaction domains, and finished with an inspiring talk on the management of research and innovation at Air Liquide.

 

EASISchool 2 participants at the top of the beautiful site of the Bastille summit, Grenoble.

During the school in Grenoble, participants also had a unique chance to visit Air Liquide Advanced Technologies headquarters and take a guided tour in the space application clean room, the turbo-expanders test facility and the large helium liquefier/refrigerator/cryolines construction workshop. Moreover, participants had a chance to visit the Cryogenic Laboratories of CEA-Grenoble, France’s National High Magnetic Field laboratory and the European Synchrotron Radiation Facility in Grenoble, learning about the diverse research programs in condensed and living matter using the world's most intense X-ray source.

 

Visit to the turbo-expander test bench at Air Liquide Advanced Technologies factory

EASISchool 2 also featured satellite public events including the opening of the public travelling exhibition “The Code of the Universe”, installed for three months at the MINATEC site at Grenoble, France. The photographic exhibition opened on the 18th of September followed by a public lecture of the FCC-ee co-leader, Prof. Alain Blondel (University of Geneva) who discussed the challenges of designing the Future Circular Collider as humanity’s next adventure. The exhibition was also part of the “Grenoble Fête de la Science 2019” giving the opportunity to thousands of visitors to visit it and learn more about the technologies needed to progress in fundamental physics. Moreover, Jakub Tkaczuk, a MSCA EASITrain fellow working in CEA-Grenoble, offered guided visits for local primary and high schools. A public conference “La cryogénie au service des découvertes scientifiques” (Cryogenics for scientific discoveries) concluded this EASITrain animation at the “Grenoble Fête de la Science 2019”.

 

EASITrain animation around the exhibition “The Code of the Universe” at the French “Fête de la Science 2019”on the 10th and 12th of October 2019 at MINATEC, Grenoble. Jakub Tkaczuk (MSCA Early Stage Researcher) initiated more than 400 students from primary and high schools to discover the superconducting and cryogenic applications.

The scientific and social program of the school offered valuable insights into novel approaches in cryogenics, and valuable networking with experts from different fields. Constructive discussions during the school proved that challenges become manageable from different angles and creative solutions sometimes emerge. Stay tuned for the next EASISchool that will take place in September 2020 in Genova, Italy.

 

Interview by Romain Muller (CERN)
Behind the scenes at the Big Science Business Forum (BSBF): New procurement practices can support large research organisations
3 Jul 2018

Behind the scenes at the Big Science Business Forum (BSBF): New procurement practices can support large research organisations

An interview with Anders Unnervik, Head of the Procurement and Industrial Services Group at CERN

Panagiotis Charitos
FCC Week 2019 accelerates progress towards post-LHC colliders
12 Jul 2019

FCC Week 2019 accelerates progress towards post-LHC colliders

Academic and research institutes, industrial partners and funding agencies met in Brussels for the Future Circular Collider (FCC) study annual meeting.

Shane Koscielniak (TRIUMF), Tor Raubenheimer (SLAC)
Highlights from IPAC ’18
28 Jun 2018

Highlights from IPAC ’18

A selection of highlights from the results presented during IPAC18

International HiRadMat Workshop

The much anticipated International HiRadMat Workshop took place in the summer of 2019 at CERN, Geneva, Switzerland with great success.  

In brief, the HiRadMat (High Radiation to Materials) facility was initially designed as a test bed for collimator related issues linked with thermal shock investigations.  However, with the experience and knowledge gained over the years since its commissioning the research topics have gradually been extended to other areas of accelerator technologies, for example testing of beam diagnostic systems, materials examination and prototype validation; all supported by granting beam time to external users.  HiRadMat is a unique user facility at CERN designed to provide high energy, high-intensity, pulsed beams to a multitude of experiments where the beam is extracted from the CERN SPS (Super Proton Synchrotron) with up to a few 1013 protons/pulse at a momentum of 440 GeV/c.

Since commissioning in 2012, HiRadMat has completed over 40 experiments and thanks to the past EuCARD, and EuCARD-2 co-fund, and more recently with the ARIES European Programme, several user teams could take advantage of the facility through Transnational Access support.  Researchers primarily from Europe, but also from the US and Japan, gained access to the facility amounting to more than 4500 Transnational Access hours since the start of operation.

Credit: Athina Papageorgiou Koufidou 

The International HiRadMat Workshop was held from 10th – 12th July 2019 at CERN.  The mandate of the workshop was to determine the future needs of HiRadMat beyond LS2.  The workshop brought together a range of scientific communities to exchange ideas on current and future projects with objectives linked to the experimental goals of HiRadMat, i.e. High Radiation to Materials research.  81 attendees participated in the event which included 37 presentations from 12 different scientific topic areas including spallation sources, targetry, fusion, materials science and engineering.  The workshop concluded with an extensive discussion session followed by a tour of the HiRadMat experimental area and a guided CERN tour of the ATLAS visitor centre and the CERN Synchrocyclotron.

International Hiradmat workshop global attendee distribution

Global spread of attendees at International HiRadMat Workshop.

From the range of presentations at the event there was a clear interest in the future operation of the facility.  HiRadMat has been identified by not only the accelerator physics and targetry communities, but by materials scientists, engineers and theorists as a unique facility offering the opportunity to perform controlled experiments with specialised beam parameters, not found elsewhere.  Similarly, with already 12 letters of interest for future experiments submitted prior to the workshop, and several more expected, there is undoubtedly support for experimental campaigns beyond LS2.

Full details including abstracts and presentations can be found on the workshop indico page: https://indico.cern.ch/event/767689/overview

Credit group picture: Julien Marius Ordan

Alexandra Welsch (University of Liverpool)
Physics of Star Wars: Science or Fiction?
7 Dec 2017

Physics of Star Wars: Science or Fiction?

Accelerator experts bring the Force to life.

Ricardo Torres (University of Liverpool)
EuPRAXIA marks two years of research into plasma accelerators
11 Dec 2017

EuPRAXIA marks two years of research into plasma accelerators

EuPRAXIA is designing the world’s first multi-GeV user-ready plasma accelerator

Francisco Sanchez Galan
P8 towards HL-LHC thanks to a new absorber
20 Oct 2019

P8 towards HL-LHC thanks to a new absorber

The first definitive component of the High-Luminosity LHC has been installed, in a prime example of collaboration across different groups.

Bringing particle accelerators on ships

The captain of the Orkāns on the bridge

The captain of the Latvian tugboat Orkāns (“storm” in Latvian) could not believe his eyes when he saw a dozen physicists, engineers and technicians from four different European countries hastily working on the funnel of his vessel moored at the Riga Shipyard on the Baltic Sea. They were connecting a long pipe to a strange truck installed on shore. The reason for this turmoil is the choice of old and rusty Orkāns as a test-bed for the first futuristic experiment of cleaning the exhaust gas of a ship diesel engine, using a particle accelerator, with the goal of reducing the content of harmful pollutants.

The tugboat Orkāns. (Image: ARIES)

Maritime traffic is the largest contributor to air pollution at planetary level – a single cruise ship emits as much particulates as one million cars. To reduce its impact on the environment, stringent regulations will be implemented in the near future. Several technologies are being explored to reduce the content of sulphur and nitrogen oxides and of particulate matter in the exhausts of maritime diesel engines.

The solution proposed by accelerator scientists consists in a hybrid technology combining irradiation by an electron beam accelerator of a few hundred kilovolts, and subsequent purification in a “wet scrubber”. The electrons induce molecular excitation, ionization and dissociation, thus breaking the larger NOx and SOx molecules, and easing their removal in a small scrubber placed after the accelerator. The scrubber washes out the polluting molecules using water.

The test area, with the tugboat on the right, the accelerator truck in the center and the scrubber on the left. (Image: ARIES)

The Institute of Nuclear Chemistry and Technology (INCT) of Warsaw (Poland) is at the origin of this technology, which was immediately adopted by the ARIES (Accelerator Research and Innovation for European Science and Society) Horizon 2020 Integrating Activity Project for Research Infrastructures. It is a remarkable example of how society could profit from particle accelerator technologies. A collaboration was formed within the Project, aiming at the real-scale test of the technology, profiting from the different competences of the ARIES partners and of the collaborative ecosystem created by the Project.

The Riga Technical University (Latvia) organized the experiment and secured the ship, the Institute of Nuclear Chemistry and Technology (Poland) designed and procured the scrubber and the closed water system and performed the tests, the Fraunhofer FEP of Dresden (Germany) made available a movable electron beam accelerator on truck routinely used to sterilize crops and contributed to the tests and to the integration. CERN, the European Organization for Nuclear Research, based in Geneva (Switzerland), provided support and consultancy.

The old and rusty Orkāns, built in Soviet times, turned out to be the perfect test bench. It is a small tugboat with a powerful, but old engine that could easily be made available for the duration of the tests. A long pipe, equipped with several detectors, connected the tugboat – moored at the Riga Shipyard – to the accelerator on-a-truck, where a specially built chamber allowed the treatment of the exhausts, which then  passed through the small scrubber, before being finally released into air.

The connecting pipe and the accelerator on truck. (Image: ARIES)

The first measurements confirmed the expected reduction in pollutants. The final results will be made available only after a full analysis of the measurements done at different engine powers and operating conditions. The data collected by this experiment will be used to finalize the proposal for the next step in the progress of this technology. A dedicated project will be submitted to a Horizon 2020 call for Societal Challenges, with the goal of installing and testing a specially designed accelerator on a real cargo ship, to be made available by the Italian Grimaldi shipping company. 

Measurement of exhaust composition. (Image: ARIES)

Toms Torims of the Riga Technical University, who supervised the test, declared, “We have to consider that this long rusty pipe actually connects two worlds, the world of shipping and the world of scientific particle accelerators. Their technologies and their languages are entirely different, but if we succeed in having them working together, we have the potential for a great advance in this technology”.

Maurizio Vretenar of CERN, coordinator of the ARIES project, added, “Technological leaps always appear at the boundary between technologies. Here, thanks to the ARIES project, we join accelerator physics, chemistry and engineering. All the conditions are there for a substantial progress towards the preservation of our environment. On top of that, we have seen people from four different European countries working together for a common goal, showing that Europeans, when united, can make great achievements”.

Stéphanie Vandergooten
Apply now to the Joint Universities Accelerator School
23 Sep 2019

Apply now to the Joint Universities Accelerator School

Interested to learn more about Particle Accelerators? Apply now to the 2020 JUAS School in Archamps to follow 5-week courses on particle accelerators.

Panagiotis Charitos (CERN)
Taking accelerators on board: Exploring unchartered waters with ARIES
11 Dec 2017

Taking accelerators on board: Exploring unchartered waters with ARIES

ARIES-Industry event brings together experts on accelerator applications for ship exhaust gas treatment.

Isabel Bejar Alonso & Francisco Sanchez Galan (CERN)
A new JTT shielding adapting ATLAS to Hilumi configuration
20 Mar 2019

A new JTT shielding adapting ATLAS to Hilumi configuration

A report/word from HL-LHC Collider-Experiment Interface Work Package

Shaping the future of accelerators: the new innovation pilot project

In the last 16 years, the particle accelerator community has been consolidated through EU support from a series of four Integrating Activities: CARE, EuCARD, EuCARD-2 and ARIES.  With the last Horizon2020 calls, the European Commission has reassessed the support for its four super-advanced communities (accelerators, lasers, synchrotron lightsources, detectors), developed and consolidated through Integrating Activities, in order to boost their innovation potential.

After consulting these communities, the EC has launched an Innovation Pilot, a different type of action from the previous Integrating Activities. The Innovation Pilot will be centred on innovation and development of new technologies, in partnership with industry. If successful, this pilot could pave the way for a long-term programme (flagship project) within the new Horizon Europe Framework Programme.

Due to the high level of integration reached by the accelerator community and the quality of the previous Integrating Activities, the EC has selected “Innovation in Accelerator Technologies” as one of the priority domains for the Innovation Pilot call INFRAINNOV-04-2020, expected to be opened in November 2019 with a deadline of 17 March 2020.

The new Accelerator Innovation Pilot Project will be structured around:

  1. Strategies/technological roadmaps in partnership with industry
  2. Initial development of accelerator technologies (low TRL = Technology Readiness Level)
  3. Prototyping for more developed technologies (higher TRL)

As was the case before, the submission of the new project will be coordinated by the TIARA (Test Infrastructure and Accelerator Research Area) Collaboration Council and the ongoing ARIES (Accelerator Research and Innovation for European Science and Society) Integrating Activity. With the goal of preparing a coherent and ambition proposal, TIARA and ARIES have launched a bottom-up call for actions to become part of the new project.

Types of actions expected for the bottom-up call:

Type of ActionPartnersExamplesBudget
Strategies/roadmaps to develop designs, technologies or applicationsSmall consortia of institutions, in partnership with industryStrategies for new accelerators and acceleration techniques, for reaching extreme performance, for extending accelerator applications, for improving accelerator components, for improving sustainability of accelerator technologies etc.300,000 EC funding + matching funds
Developments of technologies to develop an idea, component, application with long-term use (TRL 2,3,4)Small number of partners, preferably with industrial participationNew ideas or technologies that need initial validation100,000 EC funding + matching funds
Prototypes of technologies or instrumentation (TRL 4,5,6)Appropriate number of partners with industrial participationAdvanced developments of critical components, resulting from a previous preliminary development or feasibility study500,000 EC funding + matching funds

 

The proposals should be prepared following the guidelines of the letter to the accelerator community and using this template, and sent to accelerator.innovation [@] cern.ch before 31 August 2019.

They will then be evaluated by a committee nominated by the Directors of the institutions members of TIARA.

Frederick Savary (CERN)
Full length prototype of an 11T dipole magnet
27 Jun 2018

Full length prototype of an 11T dipole magnet

The construction of the 5.5-m long 11T dipole prototype was completed in May this year after several years of intense work.

Panos Charitos (CERN)
EASITrain gears up following mid-term review
12 Dec 2018

EASITrain gears up following mid-term review

The meeting offered the opportunity to young researchers to present their latest work.

Isabel Bejar Alonso (CERN) , Rama Calaga (CERN), Ofelia Capatina (CERN)
From first concept to the SPS: the challenge of the HL-LHC crab cavities cryomodules
13 Dec 2017

From first concept to the SPS: the challenge of the HL-LHC crab cavities cryomodules

Crab cavities will help increase the luminosity of collisions in the High-Luminosity upgrade of the LHC.

3D mapping of electrostatic fields

In high energy accelerators, where particles are travelling in the relativistic regime, beam bending and focusing is usually achieved by magnets. However, at kinetic energies below 100 keV, magnets become less effective for beam control. This is where electrostatic fields offer a number of distinct advantages.

Low energy antimatter and ion beam facilities rely on electrostatic beam transfer lines, as well as electrostatic elements existing in storage rings. To date, there was no analogon to the commonly used Hall probe that could precisely map the field created by electrostatic ion optics. Therefore, one had to rely on simulations like the one exemplified below to study the effects from grounded shields, manufacturing tolerances or misplacements.

Electrostatic quadrupole with grounded shield in in simulation.
(Image copyright: Physical Review Letters and Volodymyr Rodin, University of Liverpool)

 

A paper by A. Kainz et al. that was recently published in Physical Review Letters, describes a new method to precisely map the electrostatic field in an arbitrary 3D volume, with a microsensor. In a collaboration between researchers from Vienna, CERN and the University of Liverpool/Cockcroft Institute, the sensor was extensively tested to characterize an electrostatic quadrupole magnet from one of the ELENA beam transfer lines.

The functioning principle of the sensor is based on the electrostatic induction occurring inside a conducting body. The charged surfaces of the polarized conductor are, due to the external field E, subject to an electrostatic force Fe = Q E. This force is used to deflect a spring-suspended proof mass of a microelectromechanical sensor (MEMS). The deflection is recorded in an optical way, and compared to a reference system etched on the chip.

For the purpose of probing the quadrupole field, the MEMS chip was fixed inside a 3D-printed dielectric holder and connected via optical fibres to the readout electronics, placed at a remote location from the assembly. Except for the silicon part of the MEMS chip, only dielectric materials are used in the probe to minimize the sensor’s influence. The light is guided through the chip and reflected by a small right-angle prism and fed back to the fibre.

A photograph of the experimental setup us shown below:

Sensor test stand using ELENA quadrupole. ELENA is a compact ring for cooling and further deceleration of 5.3 MeV antiprotons delivered by the CERN Antiproton Decelerator. The ultimate physics goal is to perform spectroscopy on antihydrogen atoms at rest and to investigate the effect of the gravitational force on matter and antimatter. (Image: Wilfried Hortshitz, Danube University Krems)

 

Experimental results have shown that a remarkable spatial resolution can be achieved for fields with sufficiently low curvature. Measurements have also confirmed that electrostatic elements behave largely like numerical simulations predict.

Future accelerator projects, such as a storage ring to measure the electric dipole moment, will depend on the use of electrostatic elements. A field homogeneity of 1⋅10-4 or better will be required, which corresponds to extreme mechanical fabrication tolerances of only a few micrometres. A precise field measurement technique as this 3D mapping of electrostatic fields offers an interesting opportunity to relax these requirements. It offers a powerful method to mitigate any effects from tolerances, by sorting electrostatic elements or even the active compensation of unwanted effects.

The collaboration now plans to research and develop a combined sensor that can measure all three field axes at once, as well as strategies to completely eliminated effects from spatial offset.

Further reading:

Alexandra Welsch (University of Liverpool) , Panagiotis Charitos (CERN)
Marie Skłodowska-Curie's legacy inspires young scientists
11 Dec 2017

Marie Skłodowska-Curie's legacy inspires young scientists

A multi-site event to celebrate twice Nobel Prize winner’s 150th birth anniversary held in Geneva, Munich and Liverpool

Philippe Lebrun, JUAS Director
25th edition of Joint Universities Accelerator School
13 Mar 2018

25th edition of Joint Universities Accelerator School

Twenty-five years of training accelerator scientists and going from strength to strength

Ricardo Torres (University of Liverpool)
Game-changing plasma accelerator
5 Dec 2019

Game-changing plasma accelerator

EuPRAXIA project concludes its conceptual design for a powerful, small-footprint accelerator, showing that plasma acceleration provides a viable alternative to established accelerator technologies.

How fundamental science is changing our world

Fundamental science benefits society in many ways, from generating knowledge about how our universe works, to enabling unexpected and often transformative applications. Particle accelerators have been at the centre of many of the most advanced research infrastructures for decades. They have enabled many discoveries, such as the Higgs boson, and also led to the development of technologies that have changed our lives.

Future particle accelerators are expected to have a similarly bold impact on science and society. To showcase and the discuss the technologies that are currently being developed within the global Future Circular Collider (FCC) study, almost 1,000 researchers and industrialists from across Europe, university and high school students participated in “Particle Colliders – Accelerating Innovation”, an international science Symposium that took place in Liverpool on Friday 22nd March 2019.

The event, which was co-hosted by the University of Liverpool and CERN together with partners from the Future Circular Collider and EuroCirCol projects and the support of the EASITRain and AVA MSCA training networks, investigated the opportunities that a next generation of colliders can offer to industry, scientists and society.

In January 2019, CERN published the conceptual design report for the Future Circular Collider (FCC), a potential successor to the Large Hadron Collider (LHC), which aims to expand our current understanding of nature beyond the established physical model of the universe.

Professor Carsten P. Welsch, Head of the University of Liverpool Physics Department and organizer of the event, explains why fundamental research is key to advancing a knowledge-based society: “Fundamental research enables discoveries that push the boundaries of our understanding of the universe. This requires highly advanced experiments, made possible through a true global effort. Developing the design concept for future research infrastructures is not just about the science they would enable; it also requires us to drive technological progress that can benefit our everyday lives.”

The keynote talks from the Symposium were live-streamed to institutions across Europe and are now available to watch via the event website. Dozens of companies from across the UK and other EU countries showcased their latest products in an industry exhibition which followed the morning talks. The exhibition also served university students as a careers fair. They had their normal modules replaced by this unique event and found an ideal opportunity to discuss employment opportunities in different sectors. A wide range of high tech companies joined the event and provided insight into where their physics degree might take the students to next.

Image 1. Part of the outreach exhibition with the LHC interactive tunnel in the front. (Image: University of Liverpool)

More than a dozen different outreach activities, each one offered several times in parallel, were available to high school students. This included the Plasmatron, an interactive game explaining the physics behind plasma accelerators, salad bowl accelerators showing how high voltages can be generated, the augmented reality accelerator acceleratAR that turns paper cubes into components of a particle accelerator, and cryo-experiments that turned flowers into glass-like objects…which were then smashed into pieces by the children, as can be seen on the photo below.

Image 2. Part of the outreach exhibition with the LHC interactive tunnel in the front. (Image: University of Liverpool)

The entire hall was full of physics, in fact, there was even physics in the way that activities were set up as they were arranged along the spectral colours of the rainbow. A leaflet was made available to all participants and explained the link between each individual activity and ongoing accelerator science R&D.

A highlight for the hundreds of visually impaired and sighted students attending was a demonstration of the world’s first interactive ‘Tactile Collider’, which uses touch together with real sounds from the LHC to create an immersive experience. This unique experience was developed by experts from the Cockcroft Institute and has been touring the UK over the past 2 years. The event was made inclusive for VI children: in addition to tactile collider, all talks were supported by a narrator who explained the slides on display via Bluetooth headset to them. RNIB Connect Radio's Simon Pauley spoke with Dr Chris Edmonds and Professor Carsten Welsch the day before the event and you can listen to the interview here.

Finally, delegates also had the chance to play proton football and interact with visualisations of themselves in two different universes within CERN’s interactive Large Hadron Collider Tunnel, which made its UK premiere at the Symposium.

The “Particle Colliders: Accelerating Innovation” Symposium was co-hosted by the University of Liverpool and CERN, together with partners from the Future Circular Collider and EuroCirCol projects, on Friday 22 March 2019 at the ACC Liverpool. All talks and further information are available via the event website: indico.cern.ch/event/747618

Panagiotis Charitos (CERN)
Science transcends boundaries
8 Dec 2017

Science transcends boundaries

European and Japanese collaboration in the framework of the FCC study was highlighted during Science Agora 2017

Panagiotis Charitos
FCC collaboration publishes its Conceptual Design Report
28 Mar 2019

FCC collaboration publishes its Conceptual Design Report

FCC study publishes a conceptual design report demonstrating the feasibility of the different options explored for post-LHC circular colliders.

Steinar Stapnes (CERN)
Updates to the CLIC performance studies
12 Dec 2019

Updates to the CLIC performance studies

The CLIC study collaboration proposes new ways of increasing the luminosity performance at 380 GeV at modest additional cost and power consumption. These updates are summarized in a recent CLIC note.

Towards single-cycle attosecond light from accelerators

Header image (Figure 1): Technological breakthroughs in light generation and selected applications enabled by qualitatively new light source capabilities (for image sources see below*).

Methods for generating light pulses that are much shorter and brighter than currently available has been set out in a new paper by an international collaboration of accelerator scientists [1]. Figure 1 shows how throughout history the breakthroughs in light generation have revolutionized our ability to study smaller and smaller objects, from microcrystals to viruses and even to individual atoms. The discovery of X-rays at the end of the 19th century enabled diffraction imaging at the atomic scale while, with the invention of synchrotrons in the 1940’s, the photon flux became sufficient to capture the diffraction patterns of nanocrystals in the 1970’s. The time resolution at the atomic scale from these X-ray sources was, however, severely lacking.  Meanwhile, the progress in conventional laser technology, born in the 1960’s, together with the invention of chirped pulse amplification (CPA) developed in the 1980’s, now enables lasers to generate sufficient intensity to drive High-Harmonic Generation (HHG) in gases which can output attosecond duration pulses of light. However, while the femtosecond barrier was broken by laser technology and HHG, the spatial and temporal resolution potentially offered by accelerator-based X-ray sources, remains beyond their reach.

The Free-Electron Laser (FEL) is a cutting-edge, accelerator-based instrument that has the potential to provide simultaneous access to the spatial and temporal resolution of the atomic world. In a FEL, ultra-short electron bunches from an accelerator are passed through a long undulator magnet to generate coherent light. Recently, scientists from SLAC demonstrated the first generation of attosecond hard X-ray pulses, using the Linac Coherent Light Source. Now, as described in the review article by Alan Mak et al. [1], researchers are proposing developments that will make the FEL a fully coherent, single-cycle (attosecond) X-ray laser. The new concepts build upon a strong nexus between linear accelerators, FELs and quantum lasers, to produce extreme attosecond pulses with controllable waveforms.


Figure 2: The left plot in the panel (a) shows the minimum pulse duration attained over time with various demonstrated (blue) and potential (red) technologies while the right plot of the same panel depicts typical temporal waveforms. For simplicity, the period of the carrier is taken to be the same. The panel (b) presents the state-of-the-art of the pulse energy achievable by short-pulse light sources. The HHG and novel undulator concepts deliver few-cycle light pulses whereas the FEL sources shown in the figure deliver light pulses of significantly more than a few cycles. Adapted from [1].

The need for the development of a new attosecond technology is motivated by the diminishing progress in the generation of short pulses with conventional lasers, as depicted in Fig. 2a. The combination of CPA and HHG in gas allowed laser technology to break the femtosecond barrier in the 2000’s, but the initial rapid progress in pulse duration reduction has since levelled off. Another issue with conventional lasers, is that the pulse energies, critical in attosecond science, decrease rapidly as the pulses get shorter as shown in Fig. 2b. On the other hand, the attosecond regime is shown in simulations to be accessible via methods based on coherent radiation from undulators [1]. Moreover, it is seen that the pulse energy of undulator-based attosecond sources may exceed the pulse energy of the equivalent conventional laser sources by three orders of magnitude for the same pulse duration. The sub 50-attosecond, high-energy light pulse generation predicted from undulator-based technology, can therefore open up and provide access to the uncharted territory of the fastest time scales in atoms. 
 


Figure 3: Sudden radiation damage upon ionization in bio-relevant molecules and in DNA, in particular, is related to the electron-hole dynamics occurring on the sub-femtosecond scale. 

An important scientific application of such intense attosecond pulses is the study of electron flow from one region of a molecule to another, so called charge migration, which is a fundamental process in biology. As illustrated in Fig. 3, intense radiation can induce charge migration that leads to DNA and cell damage. Detailed investigations of the mechanism of charge migration are essential for understanding the processes that result in biological malfunction. Such knowledge can be obtained using the high temporal and spatial resolution offered by the proposed developments in undulator attosecond technology.

The authors of the review article have recently expanded their collaboration to form the LUSIA consortium (Towards Attosecond SIngle-cycle Undulator Light). The objectives of the consortium are to shift the paradigm of FEL pulses from long multi-cycle output, towards tailored single-cycle pulses. They aim to conduct proof-of-principle experiments leading to the development of a new enabling technology for attosecond science.


References

  • [1] Alan Mak et al “Attosecond single-cycle undulator light: a review.” Reports on Progress in Physics 82 (2019) 025901

 

* Copyright of images used in Figure 1 from left to right.

Top row:

1. Wikipedia article “Laser,” credits to David Monniaux - Kastler-Brossel Laboratory at Paris VI: Pierre et Marie Curie; 
2. Wikipedia article “Synchrotron,” credits to EPSIM 3D/JF Santarelli, Synchrotron Soleill
3. The Eurpean XFEL: https://www.xfel.eu/facility/overview/index_eng.html
4. Own artistic work
5. Own artistic work

Bottom row:

1. Google Commons.
2. Janos Hajdu “Diffraction before destruction,” talk at the Nobel Symposium on Free Electron Laser Research, 2015.
3. https://lcls.slac.stanford.edu/multimedia, “LCLS: The Linac Coherent Light Source at SLAC.”
4. N. Saito et al. "Attosecond streaking measurement of extreme ultraviolet pulses using a long-wavelength electric field." Scientific reports 6 (2016): 35594. Licensed under a Creative Commons Attribution 4.0 International License.
5. Wikipedia Commons: category “atomic orbitals.”

Editorial Team
Accelerating News Readers Survey
25 Mar 2019

Accelerating News Readers Survey

With this survey we are trying to learn more about our audience and how we can improve in the future. It should take less than 5 minutes. Thank you!

Athena Papageorgiou Koufidou, Livia Lapadatescu (CERN)
HIE-ISOLDE: challenges and future plans
15 Dec 2017

HIE-ISOLDE: challenges and future plans

HIE-ISOLDE advances the high energy frontier of the facility.

Daniela Antonio
How many points to direct the particle beam to collision?
20 Oct 2019

How many points to direct the particle beam to collision?

Developed specifically for the CERN Open Days, the activity aimed to explain the role of power converters in particle accelerators in a fun way.

Ultrafast heating of atomic clusters

Gemini amplifier. (Image: STFC, Clear Laser Facility)

Technological advances in high-power laser systems have given rise to the fast-growing and dynamic research field of laser-driven accelerators and radiation sources. Experimental and theoretical work on these topics advanced rapidly with the development of chirped-pulse amplification for lasers, which shared the 2018 Nobel Prize in Physics. This allowed for short duration laser pulses to be amplified and focused to such high intensities that electrons are stripped from their parent nuclei and oscillate at close to the speed of light in the laser fields.

At such high intensities, interactions are highly non-linear, meaning that small changes to the initial conditions can produce dramatically different results, often in ways which are difficult to predict or fully model. In experiments of this kind, there are many parameters in the laser system and interaction geometry that can be tuned to change the performance. Many of these can be also interdependent, adding to the complexity of interpretation. With so many dimensions to explore it is unlikely that the correct set of initial parameters will be chosen by chance, and so optimisation becomes very slow. In this situation it is advantageous to borrow from the on-going machine learning revolution and let computers do the hard work for us.

This is what an international team of researchers did in an experiment at the Central Laser Facility in the UK. 

Firstly, they developed the technological capability to perform high intensity laser interactions at a relatively high repetition rate (5 shots per second). Then they gave a genetic algorithm control of the laser pulse shape and programmed it to optimise the x-ray source. After 30 minutes the algorithm had more than doubled the x-ray yield from the experiment, by optimising the heating process in a target of clustered argon gas. Following the experiment, it took significantly longer to figure out what the algorithm had done and why! 

OverviewExpLayout.png
Overview of the experimental layout. (Image: Imperial College London)

 

The results of this experiment, just published in Applied Physics Letters, show that the algorithm converged towards a laser pulse temporal shape with an initially gradually rising intensity ending with a sharp peak in intensity and rapid drop. In this experiment, the laser pulse was focused onto a jet of clustered argon, which are very efficient absorbers of laser radiation, once they have expanded. However, this expansion process requires some time and so a gradual rising edge allows for this. Then, once the conditions are optimal for laser absorption, the high-intensity spike arrives and rapidly heats the plasma and leads to increased x-ray production. 

This work is the first attempt at applying machine learning techniques to such high intensity laser interactions, building on previous work with lower power but higher repetition rate laser systems. This approach allows for rapid exploration of a high-dimensional parameter space, without requiring prior understanding of what combination of parameters might be advantageous. As well as increasing the performance of the system, it also gives a new tool for understanding the physics of these systems by analysing the reasons behind the improved performance. Furthermore, active feedback techniques can also be used to stabilise performance of some system to a nominal level, adjusting laser parameters to compensate for changes in environmental conditions or aging of components. It is clear that use of such techniques will be of key importance in future experiments of this kind, and in much larger scale projects to build national and international scale facilities based on laser-plasma acceleration.

Further information: http://aip.scitation.org/doi/10.1063/1.5027297

Alessandro Bertarelli (CERN)
High thermal performance materials
8 Oct 2018

High thermal performance materials

ARIES has launched an extensive characterization campaign of a broad range of high thermal performance materials for applications in future particle accelerators and the industry.

Ch. Bracco, D. Carbajo Perez and A. Perillo Marcone
Ensuring safer operation at higher luminosities
12 Mar 2018

Ensuring safer operation at higher luminosities

The higher bunch intensities and smaller beam emittances expected in HL-LHC call for a novel design of the Target Dump Injection (TDI)

Luis Antonio González (CERN)
A novel beam screen technology for FCC-hh
25 Mar 2020

A novel beam screen technology for FCC-hh

EuroCirCol project delivers an overall integrated design for the cryogenic beam vacuum system for the challenging environment of a future 100 TeV circular proton collider.

High thermal performance materials

Figure 1. (CERN)

CERN, GSI, POLITO and POLIMI  carry out an extensive characterization campaign of a broad range of advanced materials for applications in future particle accelerators, as well as high-technology industrial domains. The collaboration characterized both novel materials, currently under development, as well as commercially available carbon-based materials, including thin-film coatings. This work has been developed in the context of the H2020 project ARIES.

The development and use of high thermal performance materials, with low mass density and excellent resistance to thermal shocks, is increasingly becoming an enabling technology in a broad range of industrial and research applications.

In industry, these materials are appealing in a number of fields, such as high power electronics, avionics, energy production, aerospace, nuclear engineering, and luxury sports automotive. Researchers and engineers working in these domains require materials with efficient thermal management, high temperature resistance and mechanical robustness. In the field of fundamental research, some components of the high-energy particle accelerators largely share these requirements. In fact, beam-intercepting devices (BID), such as collimators, beam absorbers, catchers, dumps and targets, are routinely exposed to the impact of highly energetic and intense particle beams, making the selection of key materials extremely important.

This is especially true for the next-generation of accelerator facilities like the High-Luminosity upgrade of LHC (HL-LHC) at CERN, the Facility for Antiproton and Ion Research (FAIR) at GSI, or the proposed Future Circular Collider (FCC). They will exhibit increased beam intensities (in some cases by orders of magnitude). In combination with the shorter pulse lengths and greater particle densities requested by physics experiments, this leads to significantly higher transient thermo-mechanical loads in all beam-intercepting devices. Additionally, materials for some of these components must possess high electric conductivity to limit the destabilizing effects they may induce on particle beams circulating in their close vicinity.

Unfortunately, no existing material possesses the combination of physical, thermal, electrical and mechanical properties, imposed by such extreme working conditions. For instance, the material currently employed for the absorbers of LHC Collimator jaws (a two-dimensional carbon-fibre-reinforced carbon composite – CFC – ) is predicted not to satisfy the full set of requirements imposed by the severe working conditions expected in the HL-LHC from 2026. In particular, numerical simulations indicate that the limited electrical conductivity of CFC may induce electro-magnetic instabilities in the particle beam.

In recent years, CERN has collaborated with international laboratories, universities and industries to address these issues. After having commenced in the framework of EuCARD and EuCARD-2 projects, this partnership is continuing within H2020 ARIES collaboration, Work Package 17 (PowerMat), a Joint Research Activity, in cooperation with Work Package 14 (Promoting Innovation).

Carbon-based materials have a long history of applications in beam intercepting devices and their harsh radiation environments, thanks to their low activation, high radiation-hardness, thermal stability in combination with improved strength at high temperatures and low density. PowerMat focuses on the exploration of advanced types of carbons, such as various grades of isotropic graphite, thermal pyrolytic graphite, CFC and carbon foams. It has also targeted the development of novel composite materials based on the combination of graphite and diamond with metals or high performance ceramics.

In this context, a family of new graphite-matrix composites, reinforced with molybdenum carbides (Molybdenum Carbide – Graphite, MoGr) has been co-developed by CERN and Brevetti Bizz, an Italian SME, with the goal of increasing the electrical conductivity of the materials for the primary and secondary collimator jaws, while maintaining or improving the beam impact robustness of CFC. To further enhance the electrical conductivity of the jaw surface exposed to the beam, a thin film of electrically conductive metals or ceramics can be applied to the MoGr bulk material. Solutions under development are, for example, molybdenum, copper and titanium nitride coatings.

In order to assess the performance of these materials and gain a deeper understanding of their response to beam-induced dynamic thermal shocks, dedicated experiments are carried out at facilities like CERN’s High-Radiation to Materials (HiRadMat), GSI’s UNILAC and SIS 18 accelerators, with short-pulse, high-intensity beams.

 

 

Figure 2. (CERN)

WP17 partners have performed an extensive characterization of both commercially available advanced materials and newly developed composites. The characterization performed included the study of materials morphology and microstructure, the measurement of their thermal, electrical and mechanical properties, as well as their behaviour in ultra-high vacuum, and the study of application of thin films on the surfaces of the bulk materials. This campaign has allowed quantifying the advantages of novel composites, compared to commercial materials and has laid the ground for further optimizations and improvements in the development of advanced thermal management materials. It will be complemented in the course of the projects by additional characterization campaigns, including examination after long-term irradiation and experiments under high intensity particle pulses.

During the course of this work, the ARIES Consortium also plans to engage experts from space, aviation, car and electronic industry to exchange ideas on the latest developments in design, manufacture, testing and applications of novel thermal management materials. These industries could consider the novel materials developed in this WP for advanced engineering solutions, efficient energy solutions and thermal management, given their excellent thermal conductivity and high mechanical and shock resistance.

Ubaldo Iriso (ALBA-CELLS)
Different techniques of emittance measurements for SLS and FELs
2 Mar 2018

Different techniques of emittance measurements for SLS and FELs

The status of different techniques and some new approaches of emittance measurements for SLS and FELs were analyzed in a topical workshop at ALBA.

Alexandra Welsch (University of Liverpool)
Physics of Star Wars: Science or Fiction?
7 Dec 2017

Physics of Star Wars: Science or Fiction?

Accelerator experts bring the Force to life.

Panagiotis Charitos (CERN)
EASIschool '18: A summer to remember
8 Oct 2018

EASIschool '18: A summer to remember

A unique learning experience for the participants of the first school organized by EASITrain, this summer in Vienna.

EuPRAXIA Design Study comes of age

As particle physics demands ever more powerful accelerators, the tendency is to go bigger. Dr Ralph Assmann, a leading scientist at DESY believes a completely different approach is needed. Plasma accelerators can be powerful, yet up to 1,000 smaller than conventional accelerators.

Driven by lasers or particle beams, the density oscillations in a plasma can sustain much larger fields, overcoming the breakdown limit of RF cavities. Any electrons trapped in the wake of the plasma wave, may be accelerated up to several GeV in a few millimeters. The effect is known as wakefield acceleration.

In recent years, the energies accessible to plasma wakefield accelerators have risen sharply. Scientists like Dr Assmann want to increase these energies, but also to improve the stability and quality of the electron beams coming out of the accelerator. This would make plasma accelerators suitable for particle physics but also a host of other applications like drivers for Free Electron Lasers.

Participants at the 3rd EuPRAXIA Collaboration Week. (Credit: QUASAR Group)

Dr Assmann is coordinating the project EuPRAXIA to come up with a design for the world’s first plasma wakefield accelerator with an energy of 5 GeV that can actually be used for research. That may not seem as an impressive energy but as Dr Assmann points out; you have to walk before you can run.

‘Clearly, plasma accelerators are the logical long-term solution for advancing the energy frontier in particle physics,’ he said. ‘But it will require a realistic and sustained approach.’

The EuPRAXIA consortium, comprising 40 laboratories and universities is addressing key questions, like driving the plasma with a laser or a particle beam, accelerating the electrons from the plasma or using an external injector, and employing a single stage or a multi-staged approach. The conceptual design report is expected to be completed towards the end of next year.

In order to produce a fully integrated and coherent report the frequent interaction between the work groups designing the different elements of the facility is essential. Moreover, as the layout of EuPRAXIA starts to take shape, it is time to involve the external stakeholders: the companies which will supply the technology, the scientists who will use the facility, and the students who will run it in the future.

Scientists from across Europe gathered in Liverpool to discuss the future of plasma accelerators. (Credit: QUASAR Group)

The latest of the EuPRAXIA collaboration meetings took place in Liverpool on 4 – 6 July 2018. The last day of the meeting took the form of a public event at the Liverpool Arena and Convention Centre. The Symposium ‘Quantum Leap Towards the Next Generation of Particle Accelerators’ was a special occasion to showcase the progress made within the EuPRAXIA Design Study alongside the future of plasma accelerators, advanced laser technology, and industry opportunities gathering together scientists, students, and representatives from over 40 companies.

Professor Carsten Welsch, EuPRAXIA’s Director of Communication and Head of the Liverpool Physics Department, said: ‘The collaboration week allowed a critical assessment of the research progress made across all of EuPRAXIA’s scientific work packages. On the other hand, the Symposium was ideal to present the aims and opportunities of EuPRAXIA to a much wider audience.’

The morning session of the Symposium featured talks from research leaders about the science and technology of plasma accelerators. Hands-on demonstrations helped to explain students how this new type of accelerators works and how the particle beams can be optimized. A poster session showcased the results from EuPRAXIA research to date.

‘Marshmallow waves’ helped to explain how this new type of plasma wakefield accelerator works. (Credit: QUASAR Group)

Oliver Burns, one of the 120 high school students who attended the Symposium commented: ‘This science is at the forefront of innovation, and it would be incredible to be a part of advancing the world we live in.’

In the later part of the day the event focused more on the importance of industry-academia collaboration for large scale research infrastructures. It included an industry exhibition highlighting the latest technologies and market-ready products, as well as talks about the wide range of applications in which accelerators find use.

Industry exhibition at the Symposium. (Credit: QUASAR Group)

Dr Assmann said: ‘EuPRAXIA represents the next generation of accelerators that will enable fantastic new applications. To pave the way for such a novel facility, we need to work together across research disciplines, countries and sectors.’ Quoting John Lennon, he added: ‘A dream you dream alone, is only a dream. A dream you dream together is reality.’

All the talks from the Symposium are available online and can be watched here:
http://www.eupraxia-project.eu/live-streams.html

Panagiotis Charitos (CERN)
Discussing the next step for circular colliders
12 Dec 2017

Discussing the next step for circular colliders

The 2018 Future Circular Collider collaboration meeting will take place in Amsterdam, the Netherlands (9-13 April 2018).

Constantinos Astreos (University of Liverpool)
Academia-industry collaboration drives innovation
27 Mar 2019

Academia-industry collaboration drives innovation

Co-innovation workshop focused on strategic R&D programme of future collider and the benefits for industry in terms of project involvement and product commercialisation.

L Marco Zanetti (INFN), Frank Zimmermann (CERN)
Discussing a future strategy for muon colliders
8 Oct 2018

Discussing a future strategy for muon colliders

Discussing status and ongoing efforts in light of the upcoming European Strategy update.

Setting up a South-East Europe International Institute for Sustainable Technologies

The Balkan states are joining forces to set up a South-East Europe International Institute for Sustainable Technologies (SEEIIST) with the primary goal of promoting ‘science for peace’ and the development of science and technology. This research infrastructure will be based on the CERN model and is intended to further mitigate tensions between the countries in the region by encouraging scientists and engineers to work together on one common goal.

Two scientific options are currently being discussed: the first is a fourth-generation synchrotron light source with intense beams from infrared to X-ray wavelengths; and the second is a state-of-the-art cancer therapy machine using protons and heavy ions for patient treatment with a strong research programme. Both options will be based on scientific excellence and hence on innovative cutting-edge science and technology. This international collaboration platform is also being designed to educate young scientists and engineers in the region and reverse the brain drain. Studies are currently underway to ensure the facility’s sustainability and a layer of technology transfer is also being included for the technology to be exploited by industry.  

The concept of setting up a science institute promoting ‘science for peace’ in South-East Europe was first proposed by Herwig Schopper in autumn 2016 at a meeting of the World Academy of Art and Science in Dubrovnik, Croatia. At around the same time, the setting up of a regional synchrotron light source or cancer therapy machine was also being discussed in Montenegro by the Minister of Science Sanja Damjanovich and her two international advisors Hans Specht (Heidelberg University & Former DG GSI) and Nicholas Sammut (University of Malta). This was the perfect opportunity to join both ideas together and to propose the setting up of such an institute for the benefit of all the Balkan states.

The idea took traction immediately and on the 25th of October 2017, a Declaration of Intent to establish SEEIIST, was signed at CERN by ministers of science or their representatives, independent of where the final location would be. The initial signatories were Albania, Bosnia and Herzegovina, Bulgaria, Kosovo[1], The Former Yugoslav Republic of Macedonia, Montenegro, Serbia and Slovenia. Croatia also agreed in principle and Greece participated as an observer.   

Just a few months later at the end of January 2018, a scientific forum was organised at the International Centre for Theoretical Physics (ICTP) in Trieste, Italy where the concept studies worked out by two groups of distinguished international specialists were presented and discussed. The forum was supported by the United Nations Educational, Scientific and Cultural Organisation (UNESCO), the International Atomic Energy Agency (IAEA) and the European Physical Society (EPS). Over 100 participants including scientists, engineers and policy makers from universities, industry, government and regional or international organisations attended the meeting. Amongst others, the event was also attended by the European Strategic Forum on Research Infrastructures (ESFRI) and by the European Commission, which was represented by Robert-Jan Smits (DG Research and Innovation, European Commission).

At the Forum, representatives from the IAEA declared an interest in supporting the initiative through training programmes and the European Union representatives also showed favourable support of the project potentially providing resources to support the preparation of the detailed conceptual design.

Just one week after the Trieste forum, the SEEIIST first steering committee meeting took place in Sofia, Bulgaria, which currently holds the EU presidency. The committee consisted of representatives from each of the signatory countries and was initially chaired by the Minister of Science of Montenegro. The meeting was introduced by the Bulgarian president Rumen Radew who showed strong interest and promised support of the initiative. 

With the initiative gaining more and more momentum, the next step is to take a decision on which of the two scientific options to choose to build and to set up the first executive team to be governed by the steering committee.

 

You can read a viewpoint on "Shaping science in South-East Europe" by Herwig Schopper in March's issue of CERN Courier: here

 

[1] This designation is without prejudice to positions on status and is in line with UNSC 1244/1999 and the ICJ opinion on the Kosovo Declaration of Independence.

Header image: Participants at the Trieste Forum.  

Fiona Harden, Yacine Kadi, Nikolaos Charitonidis, Aymeric Bouvard
International HiRadMat Workshop
30 Sep 2019

International HiRadMat Workshop

The much-antecipated event took place in the summer of 2019 at CERN, with great success.

P. Ferracin, E. Todesco (CERN)
Power tests of HL-LHC quadrupole
8 Oct 2018

Power tests of HL-LHC quadrupole

Successful results from the power test of the fourth short model of a Nb3Sn quadrupole for the High Luminosity upgrade.

Stéphanie Vandergooten
Apply now to the Joint Universities Accelerator School
23 Sep 2019

Apply now to the Joint Universities Accelerator School

Interested to learn more about Particle Accelerators? Apply now to the 2020 JUAS School in Archamps to follow 5-week courses on particle accelerators.