CERN: Accelerators updates en Superconducting magnets of the future in the making at CERN <span>Superconducting magnets of the future in the making at CERN</span> <span><span lang="" about="/user/146" typeof="schema:Person" property="schema:name" datatype="">cmenard</span></span> <span>Thu, 05/21/2020 - 21:06</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>Over the past thirty years, the exploration of the infinitely small has gone hand-in-hand with advances in superconducting magnets. The increasingly powerful hadron colliders, from the Tevatron, commissioned in 1983, to the LHC in 2008, have led to spectacular discoveries thanks to superconducting magnets used on an unprecedented scale. Accelerator experiments, pioneering the use of superconducting magnets, have also benefited from superconductivity, while stimulating their developments.</p> <p>The experiments and accelerators have so far used the niobium-titanium composite material, whose performance limits have been reached with the LHC. Increasing the luminosity or energy of the colliders requires higher magnetic fields and, therefore, new superconductors. This is the path that CERN has embarked on with the High-Luminosity LHC, developing magnets based on the niobium-tin compound that generate stronger fields.</p> <p>The May/June issue of the <em>CERN Courier </em>devotes its cover and a <a href="">feature article</a> to developments in superconducting magnets. Luca Bottura, Head of CERN's Magnets, Superconductors and Cryostats Group, reports on the progress of superconductor technology, the promises and challenges of niobium-tin for the HL-LHC and the FCC, and, beyond that, the potential of high-temperature superconductors. With several niobium-tin magnets undergoing tests or ready for installation, and major developments in progress, CERN is a pioneering laboratory in this technological adventure.</p> <p><em>Read the feature article: <a class="bulletin" href="">Taming the superconductors of tomorrow</a>.<a href=""> </a></em></p> </div> Thu, 21 May 2020 19:06:44 +0000 cmenard 154872 at Lucio Rossi receives a prize from the European Physical Society <span>Lucio Rossi receives a prize from the European Physical Society</span> <div class="field field--name-field-p-news-display-byline field--type-entity-reference field--label-hidden field--items"> <div class="field--item">Corinne Pralavorio</div> </div> <span><span lang="" about="/user/146" typeof="schema:Person" property="schema:name" datatype="">cmenard</span></span> <span>Wed, 05/20/2020 - 17:02</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>The accelerator group of the European Physical Society (EPS-AG) announced the winners of its 2020 prizes during the International Particle Accelerator Conference (<a href="">IPAC’20</a>), organised by the GANIL laboratory in Caen, France, which took place remotely.</p> <p>Lucio Rossi, the leader of the High-Luminosity (HL-LHC) project, was awarded the EPS-AG Rolf Widerøe Prize for his outstanding contributions to the accelerator field. The jury recognised his “pioneering role in the development of superconducting magnet technology for accelerators and experiments, its application to complex projects in High Energy Physics, including strongly driving industrial capability, and for his tireless effort in promoting the field of accelerator science and technology”.</p> <p>Having begun his career in plasma physics, Lucio Rossi moved into the field of applied superconductivity for accelerators in the early 1990s. He contributed to the development of the superconducting magnets for the superconducting cyclotron at INFN Catania, the solenoid magnet of the ZEUS experiment at DESY’s HERA accelerator and the ATLAS superconducting toroid magnet. He headed the INFN-LASA team, which in 1990 began work on the first prototype superconducting dipole magnet for the LHC, which was delivered to CERN in 1994.</p> <p>In 2001, he became the leader of CERN’s Superconducting Magnets and Cryostats group, which was responsible for developing and launching the industrial production of the superconducting magnets needed for the LHC. No less than 300 000 km of superconducting wire had to be produced for the 1700 or so main superconducting dipole and quadrupole magnets and for the several thousand corrector magnets, whose manufacture involved the transfer of complex technology to industry. With tireless energy, unfailing optimism and contagious passion, he led his team to meet that challenge, surely one of the most epic feats in CERN’s history.</p> <p>Since 2012, Lucio Rossi has been the leader of the High-Luminosity LHC project, where the complex implementation of niobium-tin superconducting technology poses a fresh challenge for the field. He is also a tireless promoter of science and technology, as the EPS jury recognised in its award citation.</p> <p><em>To find out about the other EPS-AG 2020 winners, see <a class="bulletin" href="">the article in the CERN Courier</a>.</em></p> </div> Wed, 20 May 2020 15:02:47 +0000 cmenard 154867 at Adolf Minten (1931 – 2020) <span>Adolf Minten (1931 – 2020)</span> <span><span lang="" about="/user/151" typeof="schema:Person" property="schema:name" datatype="">anschaef</span></span> <span>Wed, 04/29/2020 - 10:25</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>Adolf Minten graduated from the University of Bonn, where he worked in the team of Wolfgang Paul on the 500 MeV electron synchrotron, one of the first strong-focusing accelerators. This early work provided him with wide experience in magnet, spectrometer and beamline design, as well as electron scattering and hadron production. In 1962, Adolf joined the CERN Track Chamber division under Charles Peyrou, setting up beamlines for the 2m Bubble Chamber and actively participating in its broad physics programme. Another important milestone of his career was the year that he spent as a visiting scientist at SLAC from 1966 to 1967, where he took part in the early experiments on hadron electro-production and electron scattering at the new two-mile accelerator.</p> <p>He returned to CERN at a time of decisive developments in accelerator and detector technologies. In parallel to his continued participation in bubble-chamber experiments, he became interested in the physics programme of the Intersecting Storage Rings, the world’s first proton–proton collider, which started operation in 1971. To cope with the high interaction rates expected at this new machine, the development of track detectors focused on the Multi-Wire Proportional Chamber (MWPC) developed by Georges Charpak. One of the designs was a large multi-purpose spectrometer called the Split Field Magnet (SFM). At that time, a large-scale application of the revolutionary MWPC technology, hitherto available only in single-wire devices or small-surface detectors, presented a formidable challenge. In 1969, Adolf became responsible for the construction of the SFM facility, which covered the full solid angle with an unprecedented 300 m2 detector surface, and 70 000 wires and electronics channels. Major detector, electronics and software developments were needed to bring this project into operation in 1974.</p> <p>In 1975, to prepare for the next generation of experiments at the new SPS machine, the CERN Management proposed the creation of a new Experimental Facilities (EF) division. Adolf played a major role in the restructuring of the previous Nuclear Physics and Track Chamber divisions. He was elected to lead the new EF division, a position that required a combination of strong scientific and technical authority, and in which he commanded the unreserved respect of his collaborators. Following support provided to the major facilities for the SPS fixed-target programme, such as BEBC, the Omega spectrometer and the neutrino, muon and other experiments, his new division soon became involved in the successful experiments at the SPS proton–antiproton collider.</p> <p>In 1984, Adolf stepped down from his position as EF division leader and joined the ALEPH experiment at LEP. The LEP experiments were a quantum leap in size and complexity when compared to previous experiments and demanded new organisational structures. As head of the ALEPH steering committee, Adolf was instrumental in setting up an organisation whose role he compared to an “orchestra, where it is not sufficient that all the instruments be properly tuned, they must also harmonise”. However, his true role of an “elder statesman” went far beyond organisational responsibilities; equally important were his human qualities, which were remarkable indeed and for which he was respected by young and old.</p> <p>Adolf maintained a constant interest in DESY, where he was highly appreciated. In early 1981, Bjorn Wiik’s study group had finished the HERA design report, and the DESY Scientific Council set up an international evaluation committee to analyse it in detail. Adolf was invited to chair this committee. Its positive recommendation was a significant step towards the approval of the HERA project. He chaired the DESY Scientific Council from 1987 until 1990, during the main construction phase of the storage rings and the H1 and ZEUS multi-purpose detectors.</p> <p>Adolf retired from CERN in 1996. We remember him as a supremely well-organised scientist of deep and incisive intelligence, unafraid to challenge and question preconceived ideas, and always inspiring others to do the same. At the same time, he was a modest person who cared profoundly for all people around him, and for their families.</p> <p>Our sympathy goes to Adolf’s wife Waltrud, and to his children and their families.</p> <p class="text-align-right"><em>His friends and colleagues</em></p> </div> Wed, 29 Apr 2020 08:25:37 +0000 anschaef 154619 at HL-LHC equipment installed on both sides of the ALICE experiment <span>HL-LHC equipment installed on both sides of the ALICE experiment</span> <div class="field field--name-field-p-news-display-byline field--type-entity-reference field--label-hidden field--items"> <div class="field--item">Anaïs Schaeffer</div> </div> <span><span lang="" about="/user/151" typeof="schema:Person" property="schema:name" datatype="">anschaef</span></span> <span>Mon, 04/20/2020 - 14:49</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>The upgrades performed during Long Shutdown 2 (LS2) will allow the <a href="">ALICE</a> experiment to operate at higher luminosities than before, starting from the next run of the LHC. A higher luminosity means a higher number of collisions in the detector every instant. Yet, during heavy-ion collisions, which is the speciality of the ALICE experiment, a wider variety of particles are generated than in proton collisions. And some of these particles escape from the detector and fly alongside the beam trajectory. Two additional collimators must therefore be installed around the experiment, one for each exiting beam, to remove the particles deviating from the beam trajectory before they can reach the superconducting magnets. Indeed, particles hitting a magnet cooled down at 1.9 K (-271°C) cause it to heat up, resulting in a loss of its superconducting state.</p> <p>To host these collimators, two innovative cryostat units have been inserted along the continuous cryostats of the LHC, on both sides of LHC Point 2, where the ALICE experiment is located. These units allow a collimator that has to operate at room temperature to be inserted along the beam lines, while still ensuring continuity of all the other lines of the magnets system: that is why they are called <em>bypass</em> cryostats. This upgrade is part of the High-Luminosity LHC (<a href="">HL-LHC</a>) project, whose first components have already been put in place in the LHC tunnel during the first part of LS2.</p> <p>“These new bypass cryostats have been designed to host a TCLD (Target Collimator Long Dispersion suppressor) collimator, while connecting two adjacent cryostats to ensure the continuity of the vacuum, the cryogenic lines and the superconducting electrical cables,” explains Délio Ramos of the TE department, project engineer responsible for the magnet cryostats. The same type of bypass units will be used around LHC Point 7 for the installation of two TCLD collimators: in this case, they will be housed between two new <a href="">11-Tesla superconducting dipole magnets</a>, which are among the most innovative equipment to be installed for HL-LHC during LS2.</p> <p>At the beginning of the year, both the bypass cryostat units have been installed and interconnected and the first collimator has been installed on one side of ALICE; the second one will take up residence later this year. These collimators, which were developed alongside the new bypass cryostats, are much more compact than standard collimators. Nonetheless, a pre-existing 13-metre-long LHC cryostat unit, a so called <em>connection</em> cryostat as it ensures continuity between adjacent magnets, had to be replaced by two new ones, of a new design. These new connection cryostats are shorter (around 5 m long each) so that they can be placed, with the bypass cryostat in between, within the original 13-metre allocated slot.</p> <figure class="cds-image" id="CERN-PHOTO-201911-371-17"><a href="//" title="View on CDS"><img alt="LHC,High-Luminosity LHC,connection,cryostats,bypass,cmi" src="//" /></a> <figcaption>This new connection cryostat is around 5 m long. It has been designed to be connected to a bypass cryostat <span>(Image: CERN)</span></figcaption></figure><p>Like every connection cryostat, these new short connection cryostats ensure the continuity of electrical powering, cooling and vacuum in the magnet system, though they do not contain magnets. “As for the previous connection cryostats, the new short ones also have to ensure a beamline support and alignment which guarantee a positioning accuracy of within 0.5 mm over the cryostat’s length,” explains Arnaud Vande Craen, the TE department’s engineer-in-charge of connection cryostats. “We had to develop a smaller version of these connection cryostats fitted with an interface that is compatible with the bypass.” The new short connection cryostats have been developed and manufactured in three years.</p> <p>This project has been carried out thanks to collaboration between various teams in the Accelerators and Technology sector, which comprises the BE, EN and TE departments.</p> </div> Mon, 20 Apr 2020 12:49:10 +0000 anschaef 154553 at LHC Physics at Ten: Entering Uncharted Waters <div class="layout layout__region featured-story-page-node-layout-content"> <div class="field--items"> <div class="field--item"> <div class="component-row component-row__display__fluid section-navigation component-row__has-header effect_none is_full_height"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="cern-component-header-blocks component-header"> <div id="header-blocks--4" class="owl-carousel owl-theme component-header__carousel header-carousel"> <div class="header-block"> <div class="header-block__title"> <h3 class="header-block__name" > <span>LHC Physics at Ten: Entering Uncharted Waters</span> <span class="header-block__name__underline"></span> </h3> <span class="header-block__subhead" ><p class="text-align-center">By: <a href="/authors/achintya-rao"><span class="cern-tag">Achintya Rao</span></a></p> <p class="text-align-center">30 MARCH, 2020 · <i>Voir en <a href="/fr/news/series/lhc-physics-ten/lhc-physics-ten-entering-uncharted-waters">français</a></i></p> <hr /><p class="text-align-center">We start our <span class="cern-tag">LHC Physics at Ten</span> series with a trip down memory lane to the day when it all began</p> </span> </div> <div class="background__veil"></div> <div class="background-component background__cds_media" style="height: 100%;"> <figure class="cds-image" data-record-id="1255406" data-filename="" id="CERN-AC-1003061-112"> <a href="//" title="View on CDS"> <img alt="CERN Control Centre on 30 March 2010" src="//"/> </a> <figcaption> <span> (Image: CERN)</span> </figcaption> </figure> </div> </div> </div> <span class="component-header__scroll"></span> </div> <a class="endof-cern-header-blocks"></a> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluidcenter section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="component-margin component-margin-small" ></div> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p class="column-left image-breakout">On 30 March 2010, <strong>exactly ten years ago</strong>, a metaphorical champagne bottle was smashed across the bow of the <a href="/science/accelerators/large-hadron-collider">Large Hadron Collider</a> (and several non-metaphorical ones were popped) as CERN’s flagship accelerator embarked upon its record-breaking journey to explore strange new worlds at the high-energy frontier: <a href="/news/press-release/cern/lhc-research-programme-gets-underway">it collided protons at an energy of <strong>3.5 teraelectronvolts (TeV) per beam</strong> for the first time</a>. Since then, the largest scientific instrument ever built has enabled scientists to study a variety of physics phenomena, with its crowning achievement being the <a href="/news/press-release/cern/cern-experiments-observe-particle-consistent-long-sought-higgs-boson">discovery of the Higgs boson in 2012</a>.</p> <figure class="cds-image breakout-right" id="CERN-HOMEWEB-PHO-2010-001-1"><img alt="A screenshot of a control screen showing the LHC’s status at 13:30 on 30 March 2010. The text on top says 'Proton Physics: Stable Beams' and the image shows a graph for two proton beams at 3.5 teraelectronvolts each." src="//" /><figcaption>LHC Page 1 shortly after first high-energy collisions in the accelerator (Image: CERN)</figcaption></figure><p class="column-left image-breakout">The LHC wasn’t built just to find the Higgs boson – or prove that it didn’t exist! Over the last ten years, it has allowed scientists to test the <strong><a href="/science/physics/standard-model">Standard Model of particle physics</a></strong> with higher precision than ever before, demonstrating the theory’s robustness. In addition to the proton–proton collisions that are the LHC’s staple, scientists have used collisions of lead nuclei to recreate and examine the <strong>conditions that prevailed in the very early universe</strong>, when quarks and gluons existed freely. And the Higgs boson itself has brought entirely new perspectives to physics – an elementary particle with no intrinsic angular momentum, the first of its kind.</p> <p class="column-left image-breakout">The path to proton–proton collisions at the teraelectronvolt scale – whose story goes as far back as 1977, when such a machine was first conceived – was fraught with challenges. No hadron collider <strong>of this size and energy</strong> had been built before, and technical and scientific expertise had to be cultivated to bring it to fruition. Global collaborations were formed to design and build the detectors at each of the four collision points around the ring.</p> <p class="column-left image-breakout"><a href="/news/press-release/cern/first-beam-lhc-accelerating-science">Proton beams flew through the machine for the first time</a> on <strong>10 September 2008</strong>, but an electrical fault only nine days later put the accelerator out of action for over a year. The first low-energy collisions were achieved on 23 November 2009. A week later, the LHC <a href="/news/press-release/cern/lhc-sets-new-world-record">took over the mantle from Fermilab’s Tevatron as the world’s highest-energy collider</a>, achieving <strong>1.18 TeV in each beam</strong>. The following March, it left the shallow waters and entered uncharted territory by colliding beams at an energy of 3.5 TeV per beam. Tears of joy and relief accompanied thunderous applause in the CERN Control Centre and the experiments’ control rooms. That Tuesday, when all four of the LHC’s big detectors – <a href="/science/experiments/alice">ALICE</a>, <a href="/science/experiments/atlas">ATLAS</a>, <a href="/science/experiments/cms">CMS</a> and <a href="/science/experiments/lhcb">LHCb</a> – saw high-energy collision debris for the first time, was the culmination of <strong>over 30 years of dreams, plans and dedication</strong>. The first papers showing early results were presented days later and, within a few months, the LHC had helped “rediscover” Standard-Model particles that had originally taken decades to find.</p> <figure class="breakout-right"><div style="position: relative; padding-top: 56.25%;"><iframe allowfullscreen="" frameborder="0" src=";hl=en&amp;cc_lang_pref=en&amp;cc_load_policy=1" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></div> <figcaption>Relive the moments leading up to the first high-energy collisions at the LHC (Credit: CERN)</figcaption></figure><p class="column-left image-breakout">In the ten years since, we have witnessed the awesome capabilities of not only the LHC but also the detectors that collect data from the collisions. While the accelerator has performed <strong>beyond expectations</strong>, so too have these experimental apparatuses, receiving far greater collisions every instant than they had been designed for and filtering out the interesting ones for analysis. The collaborations operating them have published <strong>hundreds of scientific papers</strong> using data that are unique in every sense.</p> <p class="column-left image-breakout">The LHC’s saga, though, has just begun. The machine is expected to operate until the end of the ’30s and nearly 95% of the LHC’s promised data volume is still to come. However, the analysis of the data collected thus far – in particular phenomena associated with the Higgs boson – has already begun to show where a future accelerator should point its bow.</p> <p class="column-left image-breakout">In the coming weeks, to mark the first ten years of one of <strong>humanity’s greatest scientific endeavours</strong>, we will publish a series of features on covering the physics results that have shaped our understanding of the universe – from probing the Standard Model and the early universe, to the new vistas that the Higgs boson has opened up, to the mysteries of dark matter and more. Celebrate <strong>ten years of LHC physics</strong> with us.</p> </div> </div> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <hr class="column-left image-breakout" /><p class="column-left image-breakout"><i>Meanwhile, the celebrations have already begun: the latest issue of the </i><strong>CERN Courier</strong><i> has several stories that might interest you. <i><a href="">Bang, beam, bump, boson</a><i> describes life at the helm of the LHC; </i><a href="">A labour of love</a><i> focuses on the lives of the experimentalists operating the gigantic detectors; and </i><a href="">LHC at 10: the physics legacy</a><i> provides an in-depth look at the new knowledge we have gained from theory and experiment.</i></i></i></p> <p><i><i> </i></i></p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> The Large Hadron Collider began its physics programme on this day a decade ago </div> </div> </div> Mon, 30 Mar 2020 11:43:23 +0000 achintya 153509 at A demonstrator magnet produces a record magnet field <span>A demonstrator magnet produces a record magnet field</span> <div class="field field--name-field-p-news-display-byline field--type-entity-reference field--label-hidden field--items"> <div class="field--item">Corinne Pralavorio</div> </div> <span><span lang="" about="/user/146" typeof="schema:Person" property="schema:name" datatype="">cmenard</span></span> <span>Wed, 03/25/2020 - 10:06</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>One of the keys to pushing the energy limits of accelerators is being able to reach higher magnetic fields. CERN and several other laboratories around the world have launched R&amp;D programmes aimed at improving existing magnet technology. In February, a demonstrator magnet using superconducting niobium-tin, cooled to 1.9 kelvins, achieved a peak magnetic field of 16.5 tesla on the conductor, exceeding the <a href="">previous record of 16.2 tesla in 2015</a>.</p> <p>The demonstrator, known as an enhanced Racetrack Model Coil (eRMC) magnet, consists of two superimposed flat coils in the shape of a racetrack, hence its name. The coils are produced using a cable composed of multifilament composite wire made of niobium-tin, a superconductor that can reach higher magnetic fields than the niobium-titanium superconductor currently used for the magnets of the <a href="">Large Hadron Collider</a> (LHC). The dipole magnets in the LHC operate at a nominal field of 8.3 tesla.</p> <p>Niobium-tin is the material being used for some of the new magnets in the <a href="">High-Luminosity LHC</a>, the successor to the LHC, which will make use of dipole and quadrupole magnets generating a magnetic field of around 12 tesla. This increase is already significant in comparison with what can be achieved with niobium-titanium, but niobium-tin will allow even higher magnetic fields to be produced. This potential is now being explored further, notably as part of the <a href="">Future Circular Collider (FCC) study</a>. To reach a collision energy of 100 TeV using a ring with a circumference of 100 km, dipole magnets generating magnetic fields of 16 tesla are needed.</p> <p>Even though the eRMC demonstrator isn’t an accelerator magnet, its configuration allows the performance of niobium-tin conductors to be tested. During the tests, the eRMC magnet, cooled to 1.9 kelvins (the LHC’s operating temperature), reached a peak magnetic field on the conductor of 16.5 tesla. At 4.5 kelvins, this field peaked at 16.3 tesla, which corresponds to 98% of the maximum estimated performance of the superconducting cable.</p> <p>“These results and recent advances with niobium-tin magnets demonstrate the potential of this technology for a next-generation hadron collider,” emphasises Luca Bottura, leader of the Magnets, Superconductors and Cryostats (TE-MSC) group at CERN. This record is just one of many promising advances at several laboratories. Another magnet, FRESCA2, which has a 100 mm aperture, <a href="">reached a magnetic field of 14.6 tesla in 2018</a> at CERN. FRESCA2 was developed for integration into a test station for superconducting cables. Last year, Fermilab in the United States tested an accelerator-type short model dipole magnet, with a 60 mm aperture, which <a href="">reached a field of 14.1 tesla</a> at 4.5 kelvins.</p> <p>The CERN teams will continue their work to develop an accelerator magnet configuration. The eRMC demonstrator will therefore be dismantled and reassembled with a third coil on the median plane to create a 50 mm cavity.</p> </div> Wed, 25 Mar 2020 09:06:13 +0000 cmenard 153373 at LS2 Report: Consolidation of the LHC’s external beam dumps <span>LS2 Report: Consolidation of the LHC’s external beam dumps</span> <div class="field field--name-field-p-news-display-byline field--type-entity-reference field--label-hidden field--items"> <div class="field--item">Anaïs Schaeffer</div> </div> <span><span lang="" about="/user/151" typeof="schema:Person" property="schema:name" datatype="">anschaef</span></span> <span>Wed, 03/11/2020 - 10:25</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>During operation, each beam of the LHC contains about 2500 particle bunches, each in turn containing roughly 100 billion protons. The energy stored in one of these beams, 320 megajoules (MJ), is considerable, the equivalent of a TGV train travelling at 150 km/h. After the current long shutdown (LS2), in Run 3 (2021–2024), it will reach 555 MJ.</p> <p>But when these beams need to be stopped, such high energy levels are a real challenge. “To stop a beam, we need to direct it to a beam dump, a device that absorbs particle beams,” explains Marco Calviani, leader of the Targets, Collimators and Dumps section in the EN-STI group. “At the LHC, there is an external absorber for each of the two beams. They are located in two purpose-built underground caverns at Point 6 of the accelerator.”</p> <p>During Run 2, the internal peak temperature of the absorbers reached up to 1000 °C in just 100 microseconds after each beam dump. After LS2, when the LHC beams will be even more intense, the temperature could rise to 1500 °C. To cope with this, the LHC’s beam dumps consist of an 8-metre-long graphite absorber contained in a 12-mm-thick stainless-steel tube. The whole assembly, which is encased in an iron shielding structure, weighs around 7 tonnes and is filled with nitrogen gas.</p> <p>After ten years of loyal service, however, the LHC absorbers are showing signs of wear and tear. “We have detected nitrogen leaks caused by movement of the steel tube: each time a beam impacts it, the tube receives a large fraction of the energy released by the particle shower, which results in a rapid thermal expansion and vibrations,” explains Marco Calviani. “Comparing computer simulation models with instrumentation data gathered during Run 2 has given us a better understanding of the behaviour of the absorber during impact and the origin of the vibrations.”</p> <p>An upgrade of the LHC beam dumps was therefore added to the menu for LS2. One of the main modifications being made is to the support system of the absorber, which will now be suspended by high-resistance steel cables to allow better shock absorption. The transfer line from the LHC will also be physically disconnected from the absorber – beams will travel through the air for around ten metres – to avoid the propagation of vibrations to the vacuum beam tube leading from the accelerator. The upgrade work also includes the installation of new titanium-alloy beam “windows” to enclose the graphite part of the absorber in its nitrogen atmosphere.</p> <p>But there’s a problem: after ten years of use, the LHC’s main absorbers have reached a level of radioactivity that prevents teams from working in close proximity to them for long periods. “As we cannot work on the used absorbers, we have decided to upgrade the two spare absorbers, which will now become the main absorbers,” explains Marco Calviani.</p> <p>The upgrade work began at the start of February and should be finished by August, just in time for the start of the cool down of the accelerator. Instrumentation attached to the upgraded absorbers will collect data during the next run with a view to guiding the design of the absorbers for the HL-LHC, since these will need to absorb beams with an energy of 710 MJ. “This work would not be possible without the strong commitment of all involved groups and departments within the ATS Sector and HSE,” concludes Marco Calviani.</p> </div> Wed, 11 Mar 2020 09:25:22 +0000 anschaef 153285 at LS2 Report: innovation to stop protons in their tracks <span>LS2 Report: innovation to stop protons in their tracks</span> <div class="field field--name-field-p-news-display-byline field--type-entity-reference field--label-hidden field--items"> <div class="field--item">Thomas Hortala</div> </div> <span><span lang="" about="/user/21331" typeof="schema:Person" property="schema:name" datatype="">thortala</span></span> <span>Fri, 02/21/2020 - 14:08</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>The old <a href="">Proton Synchrotron (PS)</a> is being decked out with ultra-modern equipment. As part of the LHC Injectors Upgrade (LIU) project, two novel beam dumps will be installed in the PS during the <a href="">Long shutdown 2</a>, in April, with a third waiting in the wings as a spare. Two of the three dumps are almost ready and will be commissioned following metrology checks and acceptance tests for the ultra-high vacuum. This equipment will enable the PS operators to stop any type of beam circulating in the machine when necessary and thus contributes to the safe operation of the accelerator.</p> <p>This innovating beam dump is made of two materials, the second denser than the first, which absorb the energy of the particle beam. A first isostatic graphite block is used for its excellent resistance to thermal shock. The beam then meets a block made of copper, chromium and zirconium alloy, hot isostatically-pressed on three stainless steel tubes where the cooling water circulates. This last block efficiently evacuates the energy from the beam.</p> <p>The new beam dump works differently to those normally used at CERN, where particles are deflected by a kicker magnet towards a static dump. Instead, the PS’s new beam dump moves to meet the beams, oscillating to block the vacuum chamber so that the particles’ trajectory does not need to be deflected.</p> <p>The dump block oscillates up and down, gradually stopping all the beam particles. This technique is being used due to space constraints in the Proton Synchrotron: installing a static dump would have also required the addition of a beam extraction system which would take up too much room.</p> <p>For François-Xavier Nuiry, the project leader, this is the culmination of more than four years spent developing a highly complex piece of equipment. “From the very beginning, the team’s commitment has amazed me. These beam dumps would not be here if it weren’t for their collective effort. It was also a great opportunity to train students and fellows in highly technical fields.”</p> </div> Fri, 21 Feb 2020 13:08:23 +0000 thortala 153162 at How to simulate particle transport with Geant4 <span>How to simulate particle transport with Geant4</span> <span><span lang="" about="/user/151" typeof="schema:Person" property="schema:name" datatype="">anschaef</span></span> <span>Wed, 11/27/2019 - 12:14</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>CERN will host training courses on the Geant4 toolkit for the simulation of particle transport in January and March 2020. The courses will cover diverse aspects of detector simulation for experiments in High-Energy Physics or Nuclear physics, and diverse other applications.</p> <p>The course “First Steps with Geant4”, held on 21-23 January 2020, will provide an overview of the capabilities of the Geant4 simulation toolkit, and its applications in HEP detectors and beyond. Its focus will be on how to create a simple Geant4 application from scratch. Each key capability will be explained and incorporated into the application, from creating a geometry and material of the setup to selecting between the available physics options.</p> <p>Seats for this course will be available exclusively to those affiliated with CERN to register via the <a href=";TEACHREVIEW=N&amp;PTX=&amp;CID=EKP000043251&amp;TX=FORMAT1&amp;LANGUAGE_TAG=en&amp;DECORATEPAGE=N">Learning Hub</a> until 6 December. After this date, the remaining spots will be made available to anyone else.</p> <p>A second course, “Geant4 Advanced Course”, for existing Geant4 users interested to improve their understanding and usage of Geant4 will be held on 24-26 March 2020. It will cover capabilities of Geant4 relevant for creating intermediate and advanced applications in any domain, with emphasis on topics most relevant to experiments in High-Energy or Nuclear Physics. Capabilities of Geant4 related to geometry description and optimisation, propagation of tracks in electromagnetic and other fields, the simulation of optical photons and exotic particles, and the use of speedup techniques including fast simulation and event biasing will be covered.</p> <p>Registration for the Advanced course <a href=";TEACHREVIEW=N&amp;CID=EKP000040345&amp;TX=FORMAT1&amp;LANGUAGE_TAG=en&amp;DECORATEPAGE=N">is already open</a> and will be exclusive for those affiliated with CERN, until 1 February.</p> <p>The courses are mainly targeted to experimental physicists involved in High-Energy Physics or Nuclear Physics experiments. They may also be of interest to those contemplating creating or extending applications in diverse fields from medical physics (medical imaging or particle therapy), or assessing the effects of the space radiation environment on satellites.</p> <p>Please do not hesitate to contact Technical Training ( if you have further questions.</p> </div> Wed, 27 Nov 2019 11:14:42 +0000 anschaef 14235 at LS2 Report: Proton Synchrotron prepared for higher injection energies <span>LS2 Report: Proton Synchrotron prepared for higher injection energies</span> <div class="field field--name-field-p-news-display-byline field--type-entity-reference field--label-hidden field--items"> <div class="field--item">Achintya Rao</div> </div> <span><span lang="" about="/user/34" typeof="schema:Person" property="schema:name" datatype="">achintya</span></span> <span>Tue, 02/11/2020 - 10:27</span> <div class="field field--name-field-p-news-display-list-cds field--type-cerncdsmedia field--label-hidden field--item"><figure class="cds-image" data-record-id="2708037" data-filename="202001-028_23" id="CERN-PHOTO-202001-028-23"> <a href="//" title="View on CDS"> <img alt="New Kicker magnet installation in PS 2020" src="//"/> </a> <figcaption> New Kicker magnet installation in PS 2020 <span> (Image: CERN)</span> </figcaption> </figure></div> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>Proton beams entering the <a href="/science/accelerators/proton-synchrotron">Proton Synchrotron</a> (PS) from the PS Booster have to be deflected into a circulating orbit before they can be accelerated. This is done by two specialised beam-line elements: a strong magnetic septum and a fast injection-kicker magnet. The latter is a precisely synchronised electromagnet that can be switched on and off in about 100 ns, providing a stable and uniform kick that only affects the injected beam batches, while leaving the already circulating beam unperturbed.</p> <p>After the ongoing <a href="/tags/long-shutdown-2">second long shutdown of CERN’s accelerator complex</a> (LS2), the <a href="/science/accelerators/proton-synchrotron-booster">PS Booster</a> will accelerate particles to 2 GeV, almost 50% higher than the pre-LS2 value of 1.4 GeV. The PS therefore needed a new septum and a new kicker capable of coping with this increased injection energy. On 31 January, as part of the LHC Injectors Upgrade (LIU) project, the new kicker magnet was installed, replacing the kicker that had operated since 1979. The magnet will soon be aligned, connected to the vacuum system and then connected to the power and control cables.</p> <p>Like the magnet it replaced, the PS’s new kicker is made of four identical modules sitting in a 1-metre-long vacuum tank. Each module receives power from a separate pulse generator that consists of two high-power electrical switches – a main switch and a dump switch to control the pulse length – and around 280 metres of a so-called “pulse-forming line”, wound and stored on gigantic drums. These lines are thick, coaxial cables filled with sulphur hexafluoride (SF<sub>6</sub>) at a pressure of 10 bars, to provide the necessary insulation for the charging voltage of 80 kV. Since SF<sub>6</sub> is a strong greenhouse gas, special care has to be taken to ensure that it is safely manipulated and recuperated, and that the system has no leaks.</p> <p>In order to reduce the dependence on the SF<sub>6</sub>-based cables, part of the transmission line between the pulse generator and the magnet was replaced with conventional cables. “Disconnecting the SF<sub>6</sub> cables from the magnet to connect the reserves was a two-person job, and required time-consuming gas-handling procedures to be followed,” explains Thomas Kramer from the TE-ABT (Accelerator Beam Transfer) group. “On the other hand, the new conventional cables have quick-release connectors and can be operated by one person fairly quickly.”</p> <p>Kramer and colleagues also replaced the old analogue control system for the kicker, parts of which had been in place since the system was constructed in the 1970s. “Things made back then still work reliably,” smiles Kramer, while noting that the new digital systems make it possible to monitor the situation remotely.</p> <p>One element that remains to be installed is the new septum. This is a delicate device used in the injection system, composed of two cavities separated by a thin wall: one cavity allows the beams from the PS Booster to enter the PS while the second is meant for the circulating beams. The new septum, which required construction of a novel power converter, will be installed upstream of the magnet in the coming weeks.</p> <hr /><p>More photos <a class="bulletin" href="">on CDS</a>.</p> <figure><iframe allowfullscreen="" frameborder="0" height="360" scrolling="no" src=";ln=en&amp;captions=true" width="480"></iframe> <figcaption>The PS’s new kicker magnet being installed in the accelerator (<a href="">Photos: Julien Ordan/CERN</a>)</figcaption></figure></div> Tue, 11 Feb 2020 09:27:53 +0000 achintya 147898 at