The LHC relies on the injector complex to deliver beam with well-defined bunch populations and the necessary transverse and longitudinal characteristics – all of which fold directly into luminosity performance. There are several processes taking place in the PS Booster (PSB) and the Proton Synchrotron (PS) acting on the beam structure in order to obtain the LHC beam characteristics. Two processes are mainly responsible for the beam brightness: the PSB multi-turn injection and the PS radio-frequency (RF) gymnastics. The total number of protons in a bunch and the transverse emittances are mostly determined by the multi-turn Booster injection, while the number of bunches and their time spacing come from the PS RF gymnastics. The emittance of a bunch is a combined measure of the transverse size and the angular divergence of the protons in a bunch. Smaller emittance means smaller beam size and, in this particular case, smaller beam sizes at the interaction points of the LHC and thus higher luminosity.

In providing beams to the LHC, the injectors have demonstrated remarkable flexibility, and on Saturday_, 16 July the LHC made use of an imaginative beam production scheme called Batch Compression Merging and Splitting (BCMS), which offers significantly lower transverse beam size with respect to the nominal production scheme. Despite some blow-up in the LHC during the ramp, the BCMS beam gave an increase in peak luminosity of around 20% and a new record of 1.2 x 10³⁴ cm^-2s^-1.

The multi-turn injection

The beam coming from Linac 2 is continuous and is injected sequentially into each of the four PSB rings. For each ring, the injection time can be longer than the proton revolution time. It is by choosing for how many turns beam is injected from Linac 2 into the PSB that the total beam intensity per ring is controlled. To inject more than one turn of continuous beam, the process relies on varying parameters during injection, such as the position of the beam at the injection point or the field in the main bending magnets. The aim is to put the newly injected and circulating beam in a different region of the transverse phase-space (Figure 1). One consequence of such a process is that the more protons are injected, the larger the transverse emittance.

RF gymnastics and LHC bunch spacing

In order to obtain the 25-ns bunch spacing, a multiple of this value has to be found with the available PS RF harmonics: the PS has a length of 628 meters, giving a revolution time for the protons at 26 GeV of about 2.1 µs. The key harmonic to be reached is therefore H21. On H21, the bunch spacing will be 100 ns. Different RF harmonics are produced by the impressive range of RF cavities in the PS.

The nominal beam

Until recently, the nominal scheme to obtain the LHC production beam has used batches of two PSB cycles injected in a single PS cycle. Six PSB bunches are injected in the PS RF harmonic 7 (H7). The empty bucket is necessary for the PS and SPS kickers rise times. These six bunches are each longitudinally split into three to reach H21 (Figure 2), then split in two, and again in two. This results in 72 bunches spaced by 25 ns.

The Batch Compression Merging and Splitting scheme

From the discussion of multi-turn injection into the PSB, it can be seen that to reduce the emittance it would be good to inject fewer turns into the PSB rings. So, instead of taking six PSB bunches into H7, the PS takes eight bunches into H9. The total intensity needed is then equalised between all eight slots available in the two PSB cycles. Accordingly, the injected intensity per ring is reduced. Therefore, a new scheme had to be invented by the PS RF team to obtain the required LHC beam parameters from eight bunches instead of six: the BCMS injection scheme.

First, a compression is performed by incrementing the harmonic number from H9 to H14. Then, a bunch merging puts the harmonic number back to seven. From this point, the RF gymnastics are similar to the nominal beam, with the bunches split in three (Figure 3), then two and two again. The number of bunches produced is different from the normal scheme: eight bunches are merged into four, multiplied by three, two and two again. The result is 48 bunches spaced by 25 ns, which is less than the nominal 72 bunches. Therefore, the PS and SPS have to perform more cycles to fill the entire LHC, but the gain in transverse emittance leads to higher beam brightness.

Extraordinary research needs extraordinary machines: the upgrade project of the LHC, the High-Luminosity LHC (HL-LHC), has the goal of achieving instantaneous luminosities a factor of five larger than the LHC nominal value, and it relies on magnetic fields reaching the level of 12 Tesla. The superconducting niobium-titanium (NbTi) used in the LHC magnets can only bear magnetic fields of up to 9-10 Tesla. Therefore, an alternative solution for the superconducting magnets materials was needed. The key innovative technology to develop superconducting magnets beyond 10 Tesla has been found in the niobium-tin (Nb₃Sn)  compound.

This compound was actually discovered in 1954, eight years before NbTi, but when the LHC was built, the greater availability and ductility of the NbTi alloy and its excellent electrical and mechanical properties led scientists to choose it over Nb₃Sn.

The renewed interest in Nb₃Sn relies on the fact that it can produce stronger magnetic fields. In the HL-LHC, it will be used in the form of cables to produce strong 11 T main dipole magnets and the inner triplet quadrupole magnets that will be located at the ATLAS (Point 1) and CMS (Point 5) interaction points.   

The Nb₃Sn wires that will be used in the coils of the HL-LHC magnets are made up of a copper matrix, within which there are several filaments of about 0.05 mm in diameter. These filaments are not initially superconducting, as they would be too brittle to withstand the cabling process and would lose their superconducting properties Therefore, the unreacted, not-yet-superconducting Nb₃Sn wires must first be assembled into cables and the cables then wound into a coil. Finally the coil must be heat-treated at about 650 ^oC for several days to make it superconducting via a complex reaction and diffusion process.

The cabling of the strands is done in the superconducting laboratory in Building 163 using a machine, which cables together 40 unreacted strands of Nb₃Sn into what is known as a Rutherford cable. The Rutherford cable is so far the only type of superconducting cable used in accelerator magnets. It consists of several wires that are highly compacted in a trapezoidal cross section to obtain high current density.

“The Nb₃Sn cables for the 11 T dipole magnet series and for the insertion quadrupole magnets have been developed by our section here at CERN,” says Amalia Ballarino, head of the Superconductor and Superconducting Devices (SCD) section of the Magnets, Superconductors and Cryostats (MSC) group in the Technology department. “In the superconducting laboratory, in Building 163, we are now producing the series of cables for the new magnets that will be part of the HL-LHC.”

There are several challenges connected to the cabling of the wires. First of all, the mechanical deformation due to the cabling must have a negligible influence on the shape, and therefore on the electrical performance, of the internal filaments. The deformed wire must be able to cope with the heat treatment without its performance deteriorating. To assure field quality, all the wires must be cabled, with the same tension, into a precise geometry across the whole cable length.   

“With the HL-LHC, for the first time there will be Nb₃Sn magnets in an accelerator, it’s a big responsibility”, adds Ballarino. “For HL-LHC, we are not in an R&D phase anymore, and this means that we have reached the highest possible level of performance associated with the present state-of-the-art generation of Nb₃Sn wires,” points out Ballarino. “Future higher-energy accelerators will require fundamental research on Nb₃Sn wire to produce even stronger magnetic fields,” she concludes.

Since the start-up of the LHC in 2008 and the discovery of the Higgs boson in 2012, CERN’s visitor numbers have gone through the roof. On 15 July, we hit a record number of 755 visitors in one day (the average is around 400 per day). “This peak can partly be explained by the presence of participants in the International Physics Olympiad,” says Bernard Pellequer, head of the Visitors and Local Engagement section. “A tour of CERN was part of their excursion programme and it was a great pleasure for us to show them around the Laboratory.”

But CERN tours are not just for physics buffs: CERN has been listed on the TripAdvisor site since 2012, and at present tops the charts of both the 24 tours and the 28 museums listed for Geneva. CERN has also just received a 2016 Certificate of Excellence from TripAdvisor in recognition of the quality of its tours and the service it provides to visitors.

“Over 760 comments have been posted on the TripAdvisor site, mostly with a rating of ‘Excellent’ or ‘Very good’,” enthuses Bernard Pellequer. “These comments are a very useful tool for the Visits Service, as they help us to identify our audience and to respond to their expectations.” With this in mind, the Visits Service has introduced individual guided tours, which are proving to be a great success: every morning the tour slots are fully booked in less than 5 minutes.

Have you already joined the hype surrounding the No. 1 iOS and Android app “Pokémon GO” and started hunting for wild virtual Pokémon while walking through the real world? Have fun and catch them all!!! But also take some physical and digital care!

If you haven’t heard of “Pokémon GO”, it is an iOS and Android game in which your virtual avatar has to hunt for cute and sometimes less cute little monsters, so-called Pokémon (if you are as old as me or have kids, yes, those GameBoy, TV Series, card-game Pokémon!). The ultimate goal is to find and collect all 150 different Pokémon species. Your smartphone’s location information displayed on a Google map lookalike provides you with hints as to where to find them. Augmented reality is employed to project virtual Pokémon in your vicinity onto your smartphone’s camera picture so that you can catch them by throwing “Poké Balls” at them. These items can be found at other locations, known as “Poké Stops”. The more Pokémon you collect, the more powerful you become (see here for details). No harm in that, eh?

True, from a health perspective, “Pokémon GO” is great as it encourages you to walk around, which is good for all of us. But there is a snag: the app does not know about places you must not go! Walking around while staring at your smartphone’s screen already poses a safety risk. So watch where you are going! Roads. Stairs. Ditches. Open manholes. Ponds! Playing the app while riding a bike or driving(!) is stupid: it goes without saying. In addition, the app just embeds Pokémon where its algorithm deems them best suited. Arlington Cemetery, close to Washington D.C., has already asked players to refrain from playing the game on its premises. The same might be true for hospital wards. And, of course, for CERN: some buildings, caverns, tunnels and other locations on the CERN sites are definitely off limits for gaming. Don’t hunt Pokémon in these locations as it might be dangerous to your health. Some other locations might be off limits as they are private property… Worse, some criminals have used the game to lure people to deserted places, to rob them of their belongings. Think of your safety first! Watch your surroundings, be sensible and don’t get too immersed.

Digitally, there are also risks: “Pokémon GO” has not been made available in all countries, so you might think of downloading the app from dubious sources… But “dubious” already implies that you might get more that you asked for: a full compromise of your smartphone due to the app you downloaded being malicious (see “Android’s Armageddon” for examples). Better to wait to download it from the legitimate and official iOS app store or Google Play! Furthermore, as with many other apps, the “Pokémon GO” app is constantly recording your location, which has an impact on your privacy. Finally, some particularly nefarious people have also jumped on the bandwagon. Malicious e-mails are flooding the Internet all the time and now the first “phishing” e-mails have appeared, luring players to click on fraudulent links (learn here how to identify “bad” e-mails).

For further information, questions or help, check our website or contact us at Computer.Security@cern.ch.

Do you want to learn more about computer security incidents and issues at CERN? Follow our Monthly Report. 

Access the entire collection of Computer Security articles here.

by Stefan Lueders, Computer Security Team

The activities under way in the framework of the CERN Neutrino Platform are multiple and restless. Along with the refurbishment of ICARUS, another project is making great strides towards its completion: WA105. In spite of the not-so-expressive name, the technology being tested in this prototype is unprecedented.

WA105, presently at an advanced state of assembly at CERN, is a 3x1x1-metre, 25-tonne “dual-phase” liquid argon time projection chamber (DLAr-TPC) demonstrator. It has been conceived in the quest to solve the technological problems related to the next generation of neutrino detectors, whose dimensions need to be gigantic in order to thoroughly study the phenomenon of neutrino oscillations. Indeed, a major new international project called DUNE (Deep Underground Neutrino Experiment), will be made up of four such detectors, each one measuring approximatively 60x12x12 metres – that is, 50 times the size of ICARUS.

The dual-phase technology was developed by the European LAGUNA-LBNO consortium, with R&D efforts led byETH Zurichfor more than a decade. In a DLAr chamber, a region of gaseous argon resides above the usual liquid phase. Ionisation electrons drift up through the detector volume and are accelerated into the gaseous region near the top of the cryostat by a strong electric field. Here, large electron multipliers (LEM) amplify the signals by a factor of about 20 (that is, for every drifted electron, 20 electrons are produced), while a multilayer anode plane collects the charged particles and provides the spatial read-out. This type of detector has several technical advantages over the ICARUS-like, single-phase liquid argon TPC: the electrons can be drifted over a longer distance, the chamber is robust against sources of environmental electronic noise, and the efficiency of the three-dimensional reconstruction of the event is enhanced because the amplified charge signals can be shared between two independent charge collection planes.

The second demanding engineering task is connected to the cryostats of giant next-generation neutrino detectors. The solution has been found in the technology of tank ships transporting liquefied natural gas (LNG carriers). CERNis collaborating with the French enterprise Gaztransport & Technigaz (GTT), which owns the patent for a membrane-type containment system, whereby two cryogenic liners support and insulate the LNG cargo. The advantage of this system is that it’s modular and it can be assembled to encase a large volume.

“For the cryogenic system, we also took advantage of CERN’s long-standing know-how on the subject and close cooperation between the cryogenics teams at CERN and Fermilab,” says André Rubbia, spokesperson of the WA105 project and co-spokesperson of the DUNE collaboration. “In order for the TPC to operate properly and drift electrons over long distances, an extreme degree of purity better than 0.1 parts-per-billion of the liquid argon is required,” he continues. “The membrane cryostat is vital to insulate the volume from external air penetration and an effective cryogenic purification system is needed to prevent contamination from internal material.”

The WA105 demonstrator has recently been inserted into the cryostat and the plan is to have it ready for operation in October 2016. This milestone will be a very important step for the DLAr-TPC, which so far has only been demonstrated on prototypes up to 250 litres. The next step will be to test a larger (300-tonne), full-scale engineering prototype for DUNE in the EHN1 test facility extension currently under construction in the North Area at CERN.

“After a decade of R&D efforts, the CERN Neutrino Platform is playing a very important role,” Rubbia underlines. “It enabled the speeding up of the activities, also by attracting the manpower needed, and finally permitted the transition from laboratory R&D to the industrial-scale production needed for the next generation of long-baseline neutrino experiments,” he concludes.

The BBC will broadcast a new TV programme this evening, as the 2016 ICHEP conference, held in Chicago, USA, draws to a close.

Over the past week particle physicists from around the globe have showcased a wealth of brand new data and findings at the conference, including more than 100 new results from the Large Hadron Collider experiments at CERN.

The programme, Inside CERN, (broadcast on BBC2 at 8pm GMT) follows the scientists as they see if an intriguing hint from the 2015 data reappeared in the much larger 2016 data set, presented at ICHEP this year.

The process of making a discovery (follow the link to read our 12 step guide to making a discovery) is a long one, with many stages from building an experiment to collecting and analysing the data. To cover as many of these stages as possible, the BBC has been shadowing CERN scientists' progress on analysing these results since June 2015, when the LHC began running at the highest energy of an accelerator ever – 13 TeV.

Find out more about Inside CERN here 

CERN had a major presence at the ESOF2016 conference this week, largely in collaboration with our partners in EIROforum. A keynote session featuring CERN Director General, Fabiola Gianotti, EMBL Director General, Iain Mattaj, and ESO Director for Science, Rob Ivison, chaired by BBC science correspondent, Pallab Ghosh, debated the value of European collaboration in science. A double session covered the science of the EIROs, with ATLAS physicist, Claire Lee, representing CERN, and there was a session exploring the ways that the EIROforum organisations create business value locally, with Knowledge Transfer Group Leader, Giovanni Anelli, representing CERN.

The focal point of EIROforum’s presence was a stand highlighting the societal benefit of EIROforum science. Side events linked to the stand discussed subjects such as working at the EIROs, business opportunities with the EIROs, and technological innovation at the EIROs. During her day in Manchester, the Director General took time out for Pi(e) with the Prof, a chance for young researchers at the start of their careers to meet leading researchers in an informal setting.

SESAME was also present at ESOF. With the SESAME main ring nearing completion in Jordan, the laboratory is on the verge of starting its research programme. The main ring magnets and power supplies were provided under the EC-funded CESSAMag project coordinated by CERN. A keynote session discussed the scientific and diplomatic opportunities that SESAME opens up for the region and its neighbouring countries.

This summer, CERN’s outreach efforts took a step in a completely new direction as the group participated at various festivals.

Following an invitation from the European Science Open Forum 2016 held in Manchester, UK, to be part of the Bluedot Festival, we produced an hour-long musical presentation with a physics theme. This featured the “Cosmic Piano”, created by Arturo Fernandez Tellez and Guillermo Tejeda Muñoz of ALICE, and a piece created from the sonification of LHC data by Domenico Vicinanza and Genevieve Williams, of Anglia Ruskin University.

On a much bigger scale, we (the CERN outreach team) collaborated with the WOMAD Festival, to host its first World of Physics in the middle of the English countryside. The result was a three-day programme of talks including “What’s the Matter with Anti-Matter?” by Lars Joergensen, and activities such as a “Build Your Own Cloud Chamber” workshop led by Alex Brown.

Altogether, the pioneering Physics Pavilion, run in collaboration with the University of Lancaster, the IOP and the STFC and curated by Professor Roger Jones of the University of Lancaster, received over 3600 visitors, and the organisers ended up turning people away as the Pavilion reached capacity. It generated considerable media attention, including news items on the BBC, ITV and German public radio, and much enthusiastic feedback from festival-goers, many of whom asked for it to return in 2017.

One member of the public told the BBC: "Sometimes there's a feeling that science is a bit dry and separate from the rest of life. They're making it really accessible to us. It's interesting, understandable and quite beautiful."

By going to the festivals, CERN’s outreach programme succeeded in engaging people who had never been interested in physics before. I knew we’d got something right when a little girl raised her hand at the end of one session and asked the speaker “How old were you when you knew you wanted to be a physicist?”

The LHC has been in great shape over the last few months, delivering over 20 fb-1 of integrated luminosity before the ICHEP conference in Chicago at the beginning of August. This is not much below the 25 fb-1 target for the whole of 2016. With this success in mind, a break in luminosity production was taken for six days, starting on 26 July 2016, for a machine development period.

This year, 20 days of the LHC schedule are devoted to machine development with the aim of carrying out detailed studies of the accelerator. The 20 days are divided over five different periods, called MD blocks. They can be seen as an investment in the future, so the machine can produce collisions more efficiently in the months and years to come. A detailed programme is worked out for each MD block, whereby different specialist teams are assigned periods of four to twelve hours, depending on the topic, to perform their previously approved tests. The MD program continues 24 hours per day, as in normal physics operation.

One way of increasing the collision rate is to change the size of the beam at the interaction points in the centre of the experiments by changing the quadrupole settings on either side of a given experiment. During the first MD block, a novel way of doing this, known as ATS optics, was explored. This approach means that ever smaller beam sizes can be obtained in the future. The more the size of the proton bunches that make up the beam is reduced, the higher the chance of collisions.

Another area being studied is beam instability, a familiar operational problem. When beam intensity is increased, or a change is made to the way the accelerator is filled, the operations team has to adjust different machine parameters to prevent the beams becoming unstable. When instabilities arise, they can cause beam loss, which is automatically detected and can cause a beam dump to avoid any damage to the LHC. The relationship between the angle at which the beams collide in the centre of the experiments and beam stability is also being studied. The smaller the crossing angle, the better the chances for collisions and so higher instantaneous luminosities.

Another aspect of the current tests concerns the optimisation of the process for injecting proton bunches. This concerns both the beam instabilities at injection and the blow-up of the beam during the injection process.

After six days of study, the LHC resumed normal operation on 1 August 2016. Following the end of the MD period, the LHC resumed normal luminosity production. The last couple of weeks have, however, been interrupted by some technical problems in both the LHC and the injectors. Of note in the LHC are issues with the injection kickers and a potential inter-turn short in the one of the main bending magnets. Nonetheless, good performance is being delivered, with the total number of bunches per beam now at 2220 – a high for the year.

From Monday, 22 August another four days of machine development are on the programme, to study the longitudinal behaviour of the beam, gain a deeper insight into beam stability and explore different means of increasing the luminosity.

From 22-25 August 2016 CERN is hosting the CERN-BINP workshop for young scientists in e⁺e^- colliders. This year some 30 scientists from Budker Institute and 20 scientists from CERN, as well as 10 further participants from Austria, China, France, Germany and Turkey, get together to present and discuss their research on electron-positron colliders.

The workshop includes lectures by prominent scientists on accelerator design, particle detectors and physics studies. The program also foresees numerous site visits all around CERN.

Since the conference will discuss future colliders, it emphasises involving young people in the projects.

“In a sense, this workshop can be considered a showcase of the team of physicists, which will have to implement future projects,” says Evgeni Levitchev, deputy director of the Budker Institute of Nuclear Physics.

The workshop is organised in the framework of the EU-funded Cremlin project (Connecting Russian and European Measures for Large-scale Research Infrastructures), which aims at strengthening science cooperation between six Russian mega-science facilities and related research infrastructure counterparts in Europe. BINP and CERN are each engaged in the design of future state-of-the art electron positron colliders. BINP is preparing for a future Super Charm-Tau factory (SCT), which aims at producing e⁺e^- collisions up to 5 GeV centre-of-mass energy at very high intensity. In parallel CERN is hosting design studies for two different e⁺e^- colliders, FCC-ee and CLIC, with very high centre-of-mass energies ranging from 90 GeV to 3 TeV. The BINP and CERN designs address overlapping technological and scientific challenges.

“It is a great honour and pleasure for CERN to organise the CERN-BINP workshop and to exchange views and experiences with such a large delegation of young experts from Novosibirsk,” says CERN's Linear Collider Detector project leader, Lucie Linssen.

CERN is under attack. Permanently. Even right now. In particular, the CERN web environment, with its thousands of websites and millions of webpages, is a popular target for evil-doers as well as for security researchers. Usually, their attacks are unsuccessful and fade away over time. Sometimes, however, they are successful and manage to break into a CERN website or web server… It is imperative that we learn about our weaknesses before others do – and fix them!

Hackers with bad intentions are usually named “black hats” as they misuse their power to cause destruction or downtime via any weakness they can find. “Grey hats” are more moderate and might just have some fun with the weaknesses they find, for example by putting naked teddy bears or a personal message (such as “I hacked U”) on the compromised website. Last but not least, “white hats” report their findings directly to us and suggest that we take action (see https://cern.ch/security/home/en/kudos.shtml for a few examples) – and we quickly comply! We want more white hats, so in 2015 we teamed up with a number of universities worldwide and created the CERN WhiteHat Challenge (https://cern.ch/security/services/en/whitehats.shtml). Following dedicated lectures on ethics and security assessment techniques, students of those universities studying cyber security are entitled to perform penetration tests on CERN’s websites. It is a triple win as the students get to practise on live production systems, their professors don’t need to create an artificial testing environment, and CERN learns early on about vulnerabilities and weaknesses in its webpages. This has worked out well so far: students from the Universities of Rotterdam, Kent and FH St. Pölten have already reported their findings to us. Other universities are preparing for their students to take part this semester.

You might be wondering why we limit this programme to external people. We don’t! The CERN WhiteHat Challenge is also open to CERN employees and users who want to develop their penetration testing and vulnerability scanning skills. No in-depth technical expertise is needed – all you need is motivation. However, it is mandatory to take dedicated training courses covering ethics, web technologies, and an introduction to penetration testing and exploitation. This initial training cycle is complemented by in-depth courses on different subjects (e.g. cross-site scripting, command line injection) given at regular intervals.

If you are a member of CERN’s personnel and want to help us secure our web environment by becoming an official CERN white hat, please subscribe to this e-group (https://e-groups.cern.ch/e-groups/EgroupsSubscription.do?egroupName=White-Hats-Future-Candidates) and we will invite you to one of the next white hat courses in autumn 2016.

For further information, questions or help, check our website or contact us at Computer.Security@cern.ch.

Do you want to learn more about computer security incidents and issues at CERN? Follow our Monthly Report. 

Access the entire collection of Computer Security articles here.

by Stefan Lueders, Computer Security Team

The Global Innovation Index 2016 report is a leading reference on innovation and uses CERN as an example of a highly successful regional initiative. Read more here.

CERN and the University of Bath have released a new toolbox for fast, accurate 3D X-ray image reconstruction with applications in medical imaging and cancer diagnosis.

The software offers a very simple and affordable way to improve imaging and potentially reduce radiation doses for patients.

The toolbox is based on Cone Beam Computed Tomography (CBCT), a type of scanning process that takes a series of 2D X-ray pictures and that then processes them into a 3D image. As part of the collaborative project between CERN and the University of Bath, Ander Biguri, a PhD student at Bath, has reviewed a broad range of published CBCT algorithms and adapted them to be faster. Ander Biguri modified the algorithms to run on a laptop fitted with a GPU – the same graphic processor found inside video game consoles.

The new software means the medical imaging processing can run around 1000 times faster. Another strong point of the toolbox is that it makes it easier to compare reconstructions using different algorithms. The project was coordinated by Dr. Manuchehr Soleimani, from the University of Bath, and on the CERN side, by Dr. Steven Hancock and Prof. Manjit Dosanjh.

“Things that took days to process can be done in minutes on the laptop,” explains Steve Hancock.  “But it is not just about raw speed,” he adds.  “Using some of the other algorithms we can make an image to match the quality of current CT scanners but with fewer projections as input, and that means that we can potentially reduce the patient’s radiation dose by a factor of 10.”

The new software is collected in a repository called the Tomographic Iterative GPU-based Reconstruction (TIGRE) Toolbox, and is available open source. The collaboration hopes their open source approach will create a meeting point for academics and clinicians that will lead to the technology being adopted more widely and further developed.

The software creators benefited from the assistance of CERN’s Knowledge Transfer group – known as KT - dedicated to accelerating the transfer of CERN related innovation and whose aim is to maximise CERN’s positive impact on society.

“The Knowledge Transfer group helped bring the toolbox to its key stakeholders with a range of activities, from legal advice, licensing, management of the intellectual property, to the dissemination strategy,” says Tiago Araujo, KT Officer at CERN, who has been supporting the TIGRE team during the development phase with others.

“The team working on the TIGRE toolbox wanted it to be open source. In the Knowledge Transfer group, we strongly supported this idea, because it could help maximise the impact of their work on society,” says Charlyne Rabe, legal advisor in the KT group. “At CERN, we worked together with the University of Bath to ensure that the legal aspects were all in order before release,” she adds.

In addition, the TIGRE team was selected for CERN’s competitive Knowledge Transfer fund, receiving £58’000, which contributed to the funding and training of a Ph.D. student based in the UK. 

“The support and backing by the research departments at CERN and University of Bath are equally important to make sure this new technology gets out there,” says Dr. Paul Collier, head of the Beams department at CERN. The Beams department and the University of Bath contributed £25’000 and £66’000 respectively.

The new toolbox is available under an open software license on GitHub. PhD student Ander Biguri presented the recent results of the TIGRE toolbox during the CERNEarly-Career Researchers in Medical Applications talks.

For further information:

TIGRE toolbox on github.
CERN Early-Career Researchers in Medical Applications Talks
CERN tomography website
CERN Knowledge Transfer website
CERN Knowledge Transfer Fund
UK at CERN newsletter

On Monday, 5 September, the Romanian flag was raised in front of CERN for the first time, marking the country’s accession to Membership of the Organization. 

Read the article about the flag-raising ceremony for Romania.

Tuesday, 30 August was just a regular day for the 2016 LHC run. However,  on that day, the integrated luminosity delivered to ATLAS and CMS reached 25 fb^-1– the target for the whole year! 

How did we get here? A large group of committed scientists and technical experts work behind the scenes at the LHC, ready to adapt to the quirks of this truly impressive machine. After the push to produce as many proton-proton collisions as possible before the summer conferences, several new ideas and production techniques (such as Bunch Compression Multiple Splitting, BCMS) have been incorporated in the operation of LHC in order to boost its performance even further.

Thanks to these improvements, the LHC was routinely operated with peak luminosities 10%-15% above the design value of 10³⁴ cm^-2 s^-1 in July and August. This is an astounding success, also considering the fact that temporary limitations of the injectors only allow the injection of 2220 bunches per beam instead of the foreseen 2750, and that the LHC’s energy is for the moment still limited to 6.5 TeV instead of the nominal 7 TeV.

One of the main reasons behind this wonderful result is the excellent availability of all the elements of the LHC. In July and August, the average availability was of the order of 80%, with almost 50% of the time spent colliding protons in stable beam conditions.

On 18 August, the ATLAS experiment had to ramp down its magnets due to a control fault in the cryogenics plant, requiring five days to get back to normal conditions. The data recorded without magnetic field is of much less value for the physics analysis, and so the other experiments agreed to reshuffle the LHC schedule and bring forward several machine studies planned for the following week. 

The accelerator team is now very busy gearing up for the season finale, where forward proton-proton physics and proton-lead physics will replace the familiar proton-proton physics.

Before switching to proton-lead however, there are six weeks of proton-proton physics still ahead and we can look forward to a very successful year for the LHC and its experiments.

Last week CERN was visited by almost seventy participants of the Virgin Galactic space programme. They were joined by Sir Richard Branson, the famous explorer who founded the Virgin group.

 The Virgin Galactic programme is building the world’s first commercial spacecraft, and offers individuals the chance to purchase a ticket to become a space tourist. 

“CERN has created a place scientists can come and use incredible machinery to discover things and push barriers forward. It’s only through the exploration of the unknown that we can continue to grow and evolve,” Branson explained – something many of CERN’s community understand, as they strive to answer fundamental questions about our universe.

The ‘future astronauts’ were taken on a tour of SM18, the AMS control room and the CCC.

“To have an opportunity to visit CERN is a once in a lifetime opportunity so there’s no way we were going to miss it. We’re all, obviously, interested in once in a lifetime chances,” laughs Michael Gamerl, a future astronaut for the Virgin Galactic programme, who visited from California.

The group chose to come on this tour as part of this programme, after several of the future astronauts told the organising team that visiting CERN featured highly on their ‘bucket lists’.

“I find it fascinating, exploring, whether in a laboratory or going on an adventure – that’s how you want to live life,” says Gamerl.

Watch the video below to see more highlights from the Virgin Galactic visit:

Seventy-five students from around the African continent, chosen from 439 applicants, were hosted in the University of Rwanda’s College of Sciences and Technology for about 3 weeks.

The school received financial support from CERN and 19 other institutions in total, including the International Centre for Theoretical Physics (ICTP), Brookhaven National Laboratory, the South African National Research Foundation and Department of Technology, the Rwandan Ministry of Education, INFN, and other major particle physics laboratories, as well as governmental institutions in Africa, Europe and the United States.

Forty lecturers from various different fields in physics flew in from CERN and many other parts of the world to give lectures and mentor students. “What makes this programme unique is that we tailor each programme to whichever area of physics is interesting to the host country,” says Ketevi Assamagan, a physicist at Brookhaven National Laboratory in New York and a member of the international organising committee of the school. “The ultimate goal is to host the school in as many countries on the continent as possible, with the help of the host country governments.”

The biennial summer school, originally launched in South Africa in 2010, has also been hosted by Ghana in 2012 and by Senegal in 2014. The programme has grown in leaps and bounds, with each school seeing an increase in the number of applications from interested students. “The summer school was born out of a need to see African scholars represented in some of the world’s major research labs,” explains Assamagan. “Imparting STEM skills is key to making sure that our young people graduating from universities and research institutions will be going on to create jobs instead of relying on governments or private-sector salaried employment.”

In 2018 the African School of Fundamental Physics and Applications will be hosted in Namibia and promises to have an even bigger number of applications and interest from learners across Africa.

The African School of Fundamental Physics and Applications is a non-profit organisation that is passionate about increasing capacity development in fundamental physics and related applications in Africa. It was founded in 2010 with the aim of fostering collaboration through education.For more information visit the ASP website: www.africanschoolofphysics.org

Twenty-five nominations were submitted and considered by the committee, and five prizes were awarded to teams or individuals for work that had a significant impact within the last year.

The recipients of the award are:

• Roel Aaij, Sean Benson, Conor Fitzpatrick, Rosen Matev and Sascha Stahl, for having implemented and commissioned the revolutionary changes to the LHC Run-2 high-level trigger, including the first widespread deployment of real-time analysis techniques in high-energy physics;
• Kevin Dungs and Tim Head, for having launched the Starterkit initiative, a new style of software tutorial based on modern programming methods. “Starterkit is a group of physicists who want to improve the working lives of young researchers working on the LHCb experiment” (https://lhcb.github.io/starterkit/);
• Manuel Schiller, for speed improvements in the tracking of LHCb, enabling the full event reconstruction in the HLT. Manuel used advanced numerical methods to provide mathematical tools that speed up the tracking by large factors;
• Claire Prouvé, for the development of the automated RICH mirror alignment within the online framework. Claire's work has ultimately lead to RICH mirror alignment taking just 20 minutes to complete, whereas it took several days before;
• Paolo Durante, for the development of the PCIe40 board, the cornerstone of the LHCb upgrade. Paolo's contributions were crucial to demonstrate the overall superiority of the PCIe40 based-architecture, which made the LHCb upgrade technically possible, using a solution that is significantly less expensive than the original plan.

Today, at the INPC2016 conference for nuclear physics in Adelaide, Australia, two researchers were awarded the International Union of Pure and Applied Physics (IUPAP) Young Scientist Prize. Two of the three winners were awarded the prize for research either conducted at ISOLDE or closely linked to research and using data from the facility.

Dr Kara Marie Lynch, a CERN research fellow, was awarded the prize for her research using sensitive laser spectroscopy measurements.

“I’m delighted to have won this award for the work that I'm involved in at the CRIS experiment. It would not have been possible without the support and encouragement of my PhD supervisor, Kieran Flanagan, and the enthusiasm and dedication of the CRIS collaboration. ISOLDE provides an inspirational place to carry out your research, and I feel very lucky to work there,” she exclaims.

The second of the three awards went to Andreas Ekström, Chalmers University in Gothenburg, whose PhD thesis was based on research from ISOLDE.

He says: “Since 2010 I have shifted the focus of my research from 

ISOLDE experiments to theoretical nuclear physics. However, my current work is of course highly relevant for nuclear physics experiments. In particular for low-energy nuclear physics studies, such as those carried out at ISOLDE.”

"It is an honor to receive this prize. It is an international recognition and it means that the work that my colleagues and I do will have even further impact.” he says.  

Have you ever received an e-mail from a friend or someone you know and been surprised or appalled by its contents? Or, worse, have you have received a response to an e-mail that wasn’t written by you? Maybe with similarly surprising or appalling contents? If yes, welcome to the insecurity of the mail protocol, where nothing is as it seems…

No, this time we are not talking about “phishing” or malicious attachments but the very basics of the e-mail protocol. “SMTP” aka the “Simple Mail Transfer Protocol” is exactly what it says: very simple! In many respects, e-mails are identical to physical hand-written letters: you cannot deduce from the sender’s address nor from the message text whether it has really been sent by that person. Impersonation has never been as easy as with the SMTP protocol. Due to its simple design, I can pretend to be Mickey Mouse, Harry Potter or anyone else, and send you text messages resembling or contradicting Mickey’s opinion and thinking, deeply offend Hermione, bluntly lie to you, or try to lure you into disclosing secrets to me like your password (“Phishing”, you may recall). But the risk is not only that you are spammed with unwanted messages, the bigger risk is that I can diminish your reputation by sending offensive, weird or embarrassing e-mails in your name…

And there is not much we can do on the mail service or security protection side*. E-mail address spoofing is permitted by the protocol. Technically, we cannot block or filter legitimate, but misused, sender addresses – that would deeply affect the free communication of legitimate users with/to/from CERN. For the same reason, we cannot just block certain mail server addresses. And we shouldn’t, if we value the academic freedom of CERN (see our Bulletin article on “WWW Censorship? Not at CERN”). In order to combat malicious e-mails, we will soon deploy an advanced filtering engine, which will dynamically analyse all e-mails for malicious content and reject any problematic messages. But this will not cover e-mails that arrive with somehow legitimate and valid content – even if this content is wrong, offensive, contradictory, etc.

This implies that we all have to live with this kind of SPAM. And that we have to live with the fact of someone writing in our name… And hope for the recipients that they contact you to inform you of the nonsense they’ve received so that you can rectify the problem. Conversely, if you really want to be sure that the mail you just received is legitimate and comes from the person who it claims to be coming from, use common sense. Are you expecting such a mail from him/her? Do the content and context make sense? Could you call him/her to cross-check? Or, for the more technophile among you, digitally sign your mails so that the recipient can verify its real origin - you: for Microsoft Outlook, for the Mac OS mail client and for Thunderbird. Dedicated instructions for using S/MIME at CERN can be found here.

* The mail industry is trying to solve this issue with new restrictions like the SPF, DKIM and DMARC initiatives. However, as mailing lists can be incompatible with these new security features, none of them have been widely deployed, so far at least...

For further information, questions or help, check our website or contact us at Computer.Security@cern.ch.

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