CERN Accelerating science

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”.

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.

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

Daniela Antonio (CERN)
The future of communication and outreach for accelerators
10 Dec 2018

The future of communication and outreach for accelerators

Members from the accelerator communication community gathered at CERN for a workshop.

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 [@] before 31 August 2019.

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

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.

Panagiotis Charitos (CERN)
Interview with Jorgen D'Hondt
10 Dec 2018

Interview with Jorgen D'Hondt

Jorgen D'Hondt is the chairperson of the ECFA.

Marco Zanetti (INFN & Univ. Padua), Frank Zimmermann (CERN)
Workshop shines Light on Photon-Beam Interactions
7 Dec 2017

Workshop shines Light on Photon-Beam Interactions

The ARIES Photon Beams 2017 Workshop was held in Padua, Italy in late November 2017.

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:

Romain Muller (CERN)
More bang from your beam: reimagining X-ray conversion
20 Jun 2018

More bang from your beam: reimagining X-ray conversion

A solution live from the Medtech:Hack @ CERN

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.

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.

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:

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

Joseph Piergrossi (European XFEL)
New solutions for challenges among complementary light sources
8 Oct 2018

New solutions for challenges among complementary light sources

EUCALL developed strategies for laser-based and accelerator-based sources of UV/X-ray light.

Panos Charitos (CERN)
Interview with Mariana Mazzucato: Bridging Research with Innovation
25 Mar 2019

Interview with Mariana Mazzucato: Bridging Research with Innovation

Prof. Mariana Mazzucato on innovation and the concept of "missions".

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.


  • [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:
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., “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.”

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)

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.

Vitaliy Goryashko (Uppsala University), Georgii Shamuilov (Uppsala University), Peter Salén (Uppsala University), David Dunning (Cockcroft Institute, STFC), Neil Thompson (Cockcroft Institute, STFC), Brian W. J. McNeil (STFC , UPA Strathclyde)
Towards single-cycle attosecond light from accelerators
21 Mar 2019

Towards single-cycle attosecond light from accelerators

New concepts build upon a strong link between linear accelerators, FELs and quantum lasers.

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! 

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:

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.

Amy Bilton (CERN)
ATS-KT Innovation Days
10 Dec 2018

ATS-KT Innovation Days

The Accelerator and Technology sector (ATS) and the Knowledge Transfer (KT) group jointly hosted the first ATS-KT Innovation Day.

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

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.

Marlene Turner and Karl Rieger
How to slice a proton beam
20 Mar 2019

How to slice a proton beam

First clear evidence of proton bunch self-modulation and excitation of high amplitude wakefields in plasma acceleration.

Amy Bilton (CERN)
ATS-KT Innovation Days
10 Dec 2018

ATS-KT Innovation Days

The Accelerator and Technology sector (ATS) and the Knowledge Transfer (KT) group jointly hosted the first ATS-KT Innovation Day.

Alessandro Bertarelli (CERN)
Workshop for extreme thermal management materials
8 Dec 2017

Workshop for extreme thermal management materials

Researchers gathered in Turin, Italy to discuss current and future work.

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:

Martin Bellwood (University of Liverpool)
AVA – Training (anti)matters
6 Mar 2018

AVA – Training (anti)matters

Early stage AVA researchers benefit from established and bespoke training events

Sabrina El yacoubi
How to access free of charge state-of-the-art accelerator testing facilities across Europe?
Romain Muller (CERN)
More bang from your beam: reimagining X-ray conversion
20 Jun 2018

More bang from your beam: reimagining X-ray conversion

A solution live from the Medtech:Hack @ CERN

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.  

Several authors
CLIC technology lights the way to compact accelerators
5 Mar 2018

CLIC technology lights the way to compact accelerators

What if accelerators could be more compact and more cost-effective?

Alessandro Bertarelli (CERN)
Workshop for extreme thermal management materials
8 Dec 2017

Workshop for extreme thermal management materials

Researchers gathered in Turin, Italy to discuss current and future work.

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.

Marie Skłodowska-Curie's legacy inspires young scientists

“I think Marie Skłodowska-Curie represents courage; she was able to overcome all these challenges and to pursue something fearlessly. It's because of her legacy that people like me are able to come overseas and pursue our own dreams,” says Jacinta Yap, a Marie Skłodowska-Curie research Fellow.

On 7th November 2017, the twice Nobel Prize winner’s 150th birth anniversary was celebrated along with the many successes made possible by the European Union’s Marie Skłodowska-Curie Actions (MSCA) over the past 20 years, with a particular focus on accelerator science. This was done through simultaneous events at CERN in Geneva, at Ludwig Maximilian University in Munich and at the University of Liverpool.

Marie Skłodowska-Curie conducted pioneering work in radioactivity. She was the first woman to be awarded a Nobel Prize and to win two of them in different fields of science. Born in Poland, but having to resettle in France to pursue her career, she ultimately became the first woman to be a professor at the University of Paris. Her interests included medical applications of her work: during World War I she developed mobile radiography units to provide X-ray services to field hospitals.

The Marie Skłodowska-Curie Actions (MSCA) have supported the training of more than 100,000 researchers at all careers stages over the past two decades. There have been several innovative training networks in accelerator science and technology. Professor Carsten Welsch, Head of Physics at the University of Liverpool and based at the Cockcroft Institute, has initiated and coordinated five of these Pan-European networks and organised the Marie Curie day. Current and past Fellows presented their research results in the form of posters at CERN, in Munich and Liverpool to a diverse audience.

Poster session at CERN for the Marie Curie Day 2017- Image credit Sabrina El yacoubi

In Liverpool, almost 100 local high school students attended a series of activities at the University. They started their day with an introduction by Madame Curie herself (played by an actress) and a live connection to CERN for a talk by Dr Marco Silari about the “international impact of Marie Skłodowska Curie Actions on research at CERN”. The students then moved to the Central Teaching Laboratory, where they enjoyed hands-on activities on radioactivity and a poster session about MSCA-funded research and training activities.

Students taking part in hands-on activities during Marie Curie Day at the University of Liverpool. Image credit QUASAR Group.

They also participated in a poster competition about “Women in Science”. Their activities finished with a talk by Prof Welsch about “Accelerating Researcher Training” that was also live-streamed at CERN. A film contributed by the European Commission’s DG EAC, Martine Reicherts, provided additional background information and the view of the EU. Finally, the evening saw a live-streamed talk by Prof Katia Parodi about the “impact of MSCAs on education and research in ion beam cancer therapy”.

On the afternoon of the same day, a poster session hosted at CERN offered the opportunity to young researches to present their work spanning different fields from searches of new physics to the application of advanced accelerator technology. Since 2004, more than 490 fellows pursued their research at CERN while presently about 134 participants in the programme benefit for the international academic environment offered by CERN. Following past year's success, in 2018, CERN will coordinate two new MSCA actions: EASITrain that aims to advance the fields of superconductivity and cryogenics and RADSAGA focusing on electronics exposed to raditation. 
Both projects, brings together ten academic institutes and research centres of excellence and the leading European companies to advance these fields and provide training for 15 Early-Stage Researchers each. Finally, it should be noted that CERN is a beneficiary, in two other new MSCA ITN networks, namely CLOUD-MOTION related to the CLOUD experimnet and INSIGHTS  that aims to develop advanced statistical methods and apply them to current research in particle physics and beyond!

Poster Session at LMU Munich for the Marie Curie Day 2017. Image credit QUASAR Group.

Prof Welsch says: “Marie Sklodowska-Curie herself is still an inspiration to us all on so many levels. The European funding programmes that carries her name has provided fantastic support for accelerator science and offered great career opportunities for enquiring minds.”

This view is shared by research Fellows Jacinta Yap and Bianca Veglia.

Jacinta Yap is a Marie Curie research fellow from Australia, now doing her PhD in Physics at the University of Liverpool. She is part of the Optimisation of Medical Accelerators (OMA) European training programme. She says:

“I didn’t really know what I wanted to do at university. Then I came across medical physics. It’s got everything that I’m interested in and what motivates me: science, medicine, physics and all the technical aspects from engineering.

Jacinta Yap, Marie Curie Fellow. Image credit QUASAR Group.

“As a medical physicist, I will work in a hospital and interact with patients, doctors and machines, seeing first-hand the difference I am making.

“Being a woman in this field can be valuable. I find that sometimes I can think of different areas or different ideas that other people have not thought of before. It brings another perspective to a lot of things.”

Bianca Veglia is also a Marie Curie Fellow, based at the Cockcroft Institute in the UK. She is involved in the Accelerators Validating Antimatter physics (AVA) project, which is studying the properties of antiparticles. After graduating she used her knowledge of physics to provide credit risk assessment for a large consulting company before her love of science took her back to research.

“I easily found a position at a big credit risk management company because they hire lots of physicists. The work wasn’t bad but it was routine and I missed physics too much. I needed to feel part of something important.

Bianca Veglia, Marie Curie Fellow during a secondment to CERN. Image credit QUASAR Group.

“I am involved in this project about the low energy antiproton ring (ELENA) at CERN.

The ELENA ring was designed to avoid the use of thin foils to get low energy antiprotons, as thin foils lead to a lot of particles being lost. This is thrilling because it means ELENA will increase the availability of very low energy antiprotons for many different experiments.

“Because the energy is low, particles with the same charge repulse each other, creating effects within the beam. I'm studying this and also how an electron cooler can be used to keep the beam in the right shape. When it’s decelerated the particles spread so the electron cooler helps keep a slim beam inside of the machine.

“I read that Marie Curie couldn’t teach in Poland because she was a woman. But in France they created a position just to let her teach. I see so many different possible paths in front of me. I would like to share this enthusiasm, so like Marie Curie perhaps teaching would be something I would like to do in the future.”

Anna Stakia has been a Marie Skłodowska-Curie fellow in CERN’s Experimental Physics department since May 2016. She is currently working on New Physics searches and Machine Learning.

“Marie Skłodowska-Curie is without a doubt one of the most eminent figures in physics, and in science in general. I feel honoured to be part of a programme that carries her name and I am personally incredibly inspired by it.

To me, the strongest aspect of the Marie Skłodowska-Curie Programme is that it offers a broad variety of sub-academic and training options through which a fellow can navigate. In this way, any strict academic barriers are overcome. At the same time, the mobility opportunities enhance the fruitful interaction of students not only with researchers and working environments in foreign countries, but also among themselves, thus creating a fertile field for collaboration, which expands their research horizons, accelerates their progress and boosts their career potential.”

Prof Welsch concludes: “This event was an enormous success. We had hundreds of school children, students and researchers participate across the three sites, as well as more than half a Million people who read about our event via internet and social media on the day.”

Further information about Fellows and their projects, as well as all talks from Marie Curie Day 2017 can be found at


Header image: Marie Curie Day – 7th November 2017. Image credit QUASAR Group.

Chris Edmonds (University of Liverpool)
Tactile Collider
13 Mar 2018

Tactile Collider

Sensory exploration of LHC science for children with visual impairment

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.

Mauro Taborelli (CERN)
EVC-15 conference held in Geneva
8 Oct 2018

EVC-15 conference held in Geneva

The European Vacuum Conference (EVC) assembled experts from all over the world to discuss the latest developments in the field.