CERN: Experiments updates https://home.cern/ en ALICE is “FIT” for Run 3 after last new subdetector installation https://home.cern/news/news/experiments/alice-fit-run-3-after-last-new-subdetector-installation <span>ALICE is “FIT” for Run 3 after last new subdetector installation </span> <span><span lang="" about="/user/21331" typeof="schema:Person" property="schema:name" datatype="">thortala</span></span> <span>Tue, 07/06/2021 - 08:41</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>The ALICE detector is being steadily reassembled after three years of dismantling, building, testing and reinstallation of the subdetectors. This major LHC experiment received its last new subdetector on Monday, 21 June 2021, when the Fast Interaction Trigger (FIT) was lowered into the Point 2 cavern. The 300-kg disk, together with the three other FIT arrays, will serve as an interaction trigger, online luminometer, initial indicator of the vertex position and forward multiplicity counter. It is now secured next to the central tracking detectors inside the L3 magnet.</p> <p>This polyvalent subdetector was conceptualised, reviewed and approved by the ALICE Technical Board in early 2013. It is the fruit of an intense Research and Development effort involving prototype tests at the Proton Synchrotron. Among the 60-plus scientists from 17 institutions who contributed to the FIT design, construction, testing and installation, the Muscovite team at the Russian Institute for Nuclear Research faced major challenges with the design of the new, fully digital, front-end electronics and readout system.</p> <p>FIT relies on three state-of-the-art detector technologies underpinning components grouped into five arrays surrounding the LHC beamline, at -1, +3, +17, and -19 metres from the interaction point. The diversity of the detection techniques and the scattered positions are needed in order to fulfil the subdetector’s many required functionalities. Among the three components that make up the FIT detector, the FT0 is the fastest: comprising 208 optically separated quartz radiators, its expected time resolution for high-multiplicity heavy-ion collisions is about 7 picoseconds, ranking FIT among the fastest detectors in high-energy physics experiments. This impressively precise timing is crucial for online vertex determination and for identifying charged lepton and hadron species using time-of-flight.</p> <p>The second component, a segmented scintillator called FV0, innovates with a novel light-collection scheme designed and manufactured at UNAM, Mexico. The largest of the three components, the FV0 makes use of its size to provide optimal acceptance, which is vital for extracting centrality and determining the event plane – key parameters characterising a heavy-ion collision.</p> <p>Finally, the Forward Diffractive Detector (FDD), consisting of two nearly identical scintillator arrays, can tag photon-induced or diffractive processes by recognising the absence of activity in the forward direction. It also serves as a background monitoring tool.</p> <p>Now that it is soundly wedged inside the ALICE detector, the FIT is expected to stay there until the end of Run 4. Its installation, which comes after that of the <a href="https://home.cern/news/news/experiments/alice-tpc-upgraded">Time Projection Chamber</a>, the <a href="https://home.cern/news/news/accelerators/alice-takes-leap-forward-major-new-installation">Muon Forward Tracker</a> and the <a href="https://home.cern/news/news/experiments/ls2-report-upgraded-inner-tracking-system-joins-alice-detector">Inner Tracking System</a>, brings ALICE one step closer to the end of LS2 activities. The closing of the L3 magnet door and the installation of the final station of the muon spectrometer are scheduled to take place by the end of July and the end of August, respectively. Then a few months of commissioning will take ALICE to the start of Run 3, scheduled for the end of February 2022.</p> </div> Tue, 06 Jul 2021 06:41:33 +0000 thortala 157546 at https://home.cern 2021 LHCb prize winners https://home.cern/news/news/experiments/2021-lhcb-prize-winners <span>2021 LHCb prize winners</span> <div class="field field--name-field-p-news-display-byline field--type-entity-reference field--label-hidden field--items"> <div class="field--item">LHCb collaboration</div> </div> <span><span lang="" about="/user/151" typeof="schema:Person" property="schema:name" datatype="">anschaef</span></span> <span>Fri, 07/02/2021 - 12:21</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>The winners of the <a href="http://lhcb.web.cern.ch/Collaboration_prizes/Thesis_awards.html">2021 LHCb thesis prize</a> are Tom Boettcher (MIT) and Dmitrii Pereima (Kurchatov Institute, Moscow). Tom’s thesis is on the <a href="https://cds.cern.ch/record/2762054">LHCb GPU high-level trigger and measurements of neutral pion and photon production with the LHCb detector</a>, and he was particularly commended for his contributions to the novel GPU-based first-level trigger of LHCb Upgrade I. Dmitrii’s thesis is on the <a href="https://cds.cern.ch/record/2745798">Search for new decays of beauty particles at the LHCb experiment</a>, and he made significant contributions to our understanding of the X(3872) particle and the calibration of the hadronic calorimeter.</p> <p>Five sets of prizes were awarded to <a href="http://lhcb.web.cern.ch/Collaboration_prizes/Early_career_awards.html">early-career scientists</a>: Scott Ely (Syracuse) was recognised for his leadership in the Upstream Tracker project; Preema Rennee Pais (CERN) was recognised for her contributions to the Silicon Tracker and Scintillating Fibre Tracker projects and to the upgrade commissioning; Nicole Skidmore (Manchester) was recognised for her developments of offline software and data preparation; Adam Davis (Manchester) and Benedetto Siddi (INFN, Ferrara) were recognised for their innovative contributions to simulation programs; and Christoph Hasse (CERN), Arthur Hennequin (CERN), Louis Henry (CERN) and Niklas Nolte (MIT) were recognised for their developments of the software trigger in the real time analysis project.</p> <p>Many congratulations to all the winners!</p> </div> Fri, 02 Jul 2021 10:21:00 +0000 anschaef 157534 at https://home.cern From antimatter to heavy isotopes, data-taking in physics facilities is resuming at CERN https://home.cern/news/news/experiments/antimatter-heavy-isotopes-data-taking-physics-facilities-resuming-cern <span>From antimatter to heavy isotopes, data-taking in physics facilities is resuming at CERN</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>Wed, 06/30/2021 - 08:51</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>As the two-year-long shutdown of CERN’s accelerators comes to an end, some of the Laboratory’s many experiments are not waiting for the <a href="https://home.cern/science/accelerators/large-hadron-collider">Large Hadron Collider</a> (LHC) to wake up before starting to take data. The <a href="https://home.cern/science/accelerators/proton-synchrotron">Proton Synchrotron (PS)</a>, CERN’s 60-year-old particle accelerator, and its injector, the <a href="https://home.cern/science/accelerators/proton-synchrotron-booster">Proton Synchrotron Booster</a>, are <a href="https://home.cern/news/news/accelerators/ls2-report-cerns-oldest-accelerator-awakens">back in full roar after a major overhaul</a>. The Booster has begun delivering protons accelerated to 1.4 GeV to the ISOLDE facility (Isotope mass Separator On-Line Detector) and 2 GeV protons to the Proton Synchrotron, which, in turn, feeds its 26 GeV proton beam to the Antiproton Decelerator (AD, the first of the two particle decelerators of the Antimatter Factory). For the many experiments housed in these two world-class facilities, this can only mean one thing – the physics season is about to start, bringing with it the promise of exciting new results in nuclear and antimatter research.</p> <p>“After optimising the experiment when the first proton beam reached the <a href="https://home.cern/science/experiments/isolde">ISOLDE facility’s</a> target on 21 June, physics data-taking started swiftly and the first experiment finished successfully after five days,” explains Gerda Neyens, Physics Group Leader at the ISOLDE facility. At ISOLDE, collisions between the Booster proton beam and heavy targets produce rare radioactive isotopes of elements from across the periodic table, of which specific ones are selected using a combination of lasers and electric and magnetic fields. This season’s first ISOLDE results came from the <a href="https://isolde.cern/cris">CRIS experiment </a>in the form of hyperfine spectra of a series of silver isotopes synthesised within the walls of the facility. The atomic spectra of more than 20 exotic short-lived silver isotopes will reveal how the internal quantum structure, size and shape of the stable 107Ag and 109Ag isotopes change when neutrons are added to or removed from them.</p> <p>For the upcoming physics season, ISOLDE will rely on new target stations to produce the radioisotopes, as well as an upgraded charge breeder (a device that removes electrons from the heavy isotopes) and a <a href="https://home.cern/news/news/accelerators/ls2-report-first-beam-inside-upgraded-hie-isolde-facility">refurbished superconducting linear accelerator</a> to accelerate the produced radioisotopes. The nuclear reactions occurring in the facility, which mimic and help understand those taking place inside stars, can thus be studied with greater precision.</p> <p>Situated a few dozen metres away from ISOLDE, the <a href="https://home.cern/science/accelerators/antiproton-decelerator">Antimatter Factory</a> uses the Proton Synchrotron beams to create its own peculiar substance. This process resumed on 28 June with the return of the beam on the new target: antimatter is being made at CERN again as you read. In this unique factory, antiprotons are synthesised by colliding the proton beams onto a target. The stray particles are then focused back into a beam thanks to a device called a “magnetic horn”, which was completely renovated in recent years, as was the target itself. The new target is an air-cooled piece of iridium placed in a graphite matrix and enclosed in a titanium alloy double shell. It will improve antiproton production, for a reliable and stable antimatter inflow over time.</p> <p>The data-taking period that now awaits antimatter physicists has been given a boost by new machines such as <a href="https://espace.cern.ch/elena-project/SitePages/Home.aspx">ELENA</a> (Extra Low Energy Antiproton deceleration ring), a ring that efficiently decelerates the antiprotons to unprecedented levels before <a href="https://home.cern/news/news/accelerators/ls2-report-waiting-antiprotons">feeding them into the experimental area</a>. There, long-standing collaborations like <a href="https://home.cern/science/experiments/aegis">AEGIS</a>, <a href="https://home.cern/science/experiments/asacusa">ASACUSA</a> and <a href="https://home.cern/science/experiments/alpha">ALPHA</a> stand next to fresh faces like <a href="https://home.cern/news/news/experiments/new-antimatter-gravity-experiments-begin-cern">ALPHA-G</a> and <a href="https://home.cern/science/experiments/gbar">GBAR</a>, an experiment aiming to measure the freefall acceleration of antimatter under gravity. They will soon be joined by the <a href="https://home.cern/news/news/physics/cern-approves-two-new-experiments-transport-antimatter">PUMA and BASE-STEP collaborations</a>, which were recently approved by the CERN Research Board. Both of these experiments will rely on the delicate process of transporting antimatter to neighbouring areas of the CERN site to study its properties.</p> <p>Diversity is a defining characteristic of CERN, and this applies to the Organization’s research programme too. So, although the LHC and its detectors will not start buzzing and whirring for a few more months, there is no shortage of interesting developments: with antimatter and nuclear isotope data-taking and the forthcoming start of the physics season in the <a href="https://home.cern/news/news/accelerators/ls2-report-getting-ready-future-physics-east-area">East</a> and <a href="https://home.cern/news/news/engineering/ls2-report-focus-north-area">North experimental areas</a> as well as at <a href="https://home.cern/science/experiments/n_tof">n_TOF</a>, the next few months will be hectic ones for physics research.</p> <p><iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="" frameborder="0" height="420" src="https://www.youtube.com/embed/InkHaE0sXow" title="YouTube video player" width="560"></iframe><span style="font-size:12px;"><br /><em>A 360° virtual tour through the AD target area at CERN - use the arrows to change your perspective </em></span></p> </div> Wed, 30 Jun 2021 06:51:51 +0000 thortala 157517 at https://home.cern Greening gaseous detectors https://home.cern/news/news/experiments/greening-gaseous-detectors <span>Greening gaseous detectors</span> <div class="field field--name-field-p-news-display-byline field--type-entity-reference field--label-hidden field--items"> <div class="field--item">Mark Rayner</div> </div> <span><span lang="" about="/user/21331" typeof="schema:Person" property="schema:name" datatype="">thortala</span></span> <span>Tue, 06/08/2021 - 15:16</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>When charged high-energy particles crash past noble-gas molecules, they leave a trail of ionisation in their wake. These tiny signals can be amplified using electric fields, and read out by electronics, revealing particle tracks with beautiful precision. This is the time-honoured concept behind the LHC’s gaseous detectors – an indispensable concept, thanks to its ability to instrument large volumes of a detector in an affordable way.</p> <p>Unfortunately, environmentally harmful chlorofluorocarbons known as freons also play an essential role, dampening runaway effects to make sure that the amplified signals aren’t swallowed up by electronics noise. Physicists at the LHC are working on consolidating strategies for eliminating the current risks, and are studying novel “eco-gases” for the next generation of detectors. These were the topics of the <a class="bulletin" href="https://indico.cern.ch/event/1022051/">workshop</a> recently hosted online by CERN. To read more, check out the <a class="bulletin" href="https://cerncourier.com/a/greening-gaseous-detectors/">full report</a> in the <a href="https://cerncourier.com/"><em>CERN Courier </em>magazine</a>.</p> </div> Tue, 08 Jun 2021 13:16:47 +0000 thortala 157164 at https://home.cern First ATLAS New Small Wheel nears completion https://home.cern/news/news/experiments/first-atlas-new-small-wheel-nears-completion <span>First ATLAS New Small Wheel nears completion</span> <div class="field field--name-field-p-news-display-byline field--type-entity-reference field--label-hidden field--items"> <div class="field--item">Katarina Anthony</div> </div> <span><span lang="" about="/user/21331" typeof="schema:Person" property="schema:name" datatype="">thortala</span></span> <span>Mon, 06/07/2021 - 09:32</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>These now-iconic detectors are critical to a new era of exploration for the ATLAS experiment. In the coming years, a major upgrade to the LHC – known as the <a href="https://home.cern/science/accelerators/high-luminosity-lhc">High-Luminosity LHC</a> – aims to crank up the collider's luminosity by a factor of ten beyond its design value. This will generate even more collisions, allowing ATLAS physicists to probe <a href="https://atlas.cern/updates/news/scientific-potential-high-luminosity-lhc">phenomena that are even rarer in nature</a>.</p> <p>A massive upgrade of the ATLAS experiment is underway to prepare for this increased luminosity. The first major system to be upgraded is the muon spectrometer, with the New Small Wheels set to be installed on either end of the experiment in summer and autumn 2021. The wheels use novel small-strip Thin Gap Chambers (sTGC) and Micromegas detectors. These new technologies will give ATLAS much more stringent selection criteria for muons, and better handle high background and pile-up rates – the two main requirements for the High-Luminosity LHC.</p> <p>The New Small Wheels were built in ATLAS institutes around the world and mounted on their support at CERN over the course of several years. Following the installation of the last "wedge" of detectors, the first New Small Wheel is now complete, with just final testing and commissioning pending.</p> <p>Look forward to watching the installation of this “small” behemoth, set to be broadcast live on CERN and ATLAS channels this summer.</p> <p><em>_____</em></p> <p><em>To find out more and view more photos, visit the <a class="bulletin" href="https://atlas.cern/updates/news/NSW-final-slice ">ATLAS website</a>. </em></p> </div> Mon, 07 Jun 2021 07:32:42 +0000 thortala 157149 at https://home.cern LS2 Report: An upgraded Inner Tracking System joins the ALICE detector https://home.cern/news/news/experiments/ls2-report-upgraded-inner-tracking-system-joins-alice-detector <span>LS2 Report: An upgraded Inner Tracking System joins the ALICE detector </span> <span><span lang="" about="/user/21331" typeof="schema:Person" property="schema:name" datatype="">thortala</span></span> <span>Wed, 05/26/2021 - 09:29</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>After two nerve-wracking months dedicated to the installation of the ALICE detector’s new Inner Tracking System (ITS), Corrado Gargiulo’s mechanical engineering team, in charge of the installation, can relax: the delicate procedure has been successfully completed and ALICE’s innermost subdetector is poised to collect its first data in the coming weeks.</p> <p>With its 10 m<sup>2</sup> of active silicon area and nearly 13 billion pixels, the new ITS is the largest pixel detector ever built. The detector lies sandwiched between the beam pipe and the Time Projection Chamber, <a href="https://home.cern/news/news/experiments/alice-tpc-upgraded">which was installed in 2020</a>, deep in the ALICE detector. By reconstructing primary and secondary particle vertices and improving the momentum and angle resolution for particles reconstructed by the Time Projection Chamber, the ITS is instrumental in identifying the particles born out of the powerful lead–lead collisions in the core of the ALICE detector.</p> <p>The upgrade of the ITS will significantly increase the resolution of the vertex reconstruction, making the subdetector fit for future runs with higher luminosity, as part of a comprehensive overhaul of ALICE’s subdetectors striving for this very objective. The current upgrade relies on new pixel sensors called ALPIDE, which also make up <a href="https://home.cern/news/news/accelerators/alice-takes-leap-forward-major-new-installation">the new Muon Forward Tracker</a> (MFT), installed a few months ago. Each of those chips contains more than half a million pixels in an area of 15 × 30 mm<sup>2</sup> and features an impressive resolution of about 5 μm in both directions – the secret to the subdetector’s improved performances. They are organised in seven layers, the innermost three forming the inner barrel, while the outermost four make up the outer barrel. The collected data is then transmitted with a bit rate of up to 1.2 Gb/s to a system of about 200 readout boards located 7 m away from the detector. The data is then aggregated and eventually sent to ALICE’s computing farm, where it is sequenced and processed.</p> <p>The insertion of the heart of the ALICE detector around its beam pipe required surgical-like precision. The installation unfolded in two stages, as the two barrels making up the ITS had to be lowered separately, two months apart. The outer barrel got the ball rolling: it was loaded onto a truck in March and transported from Meyrin to Point 2, where the mating of its two halves and its insertion in the detector were carried out smoothly.</p> <figure class="cds-image" id="ALICE-PHO-ITS-2021-001-13"><a href="//cds.cern.ch/images/ALICE-PHO-ITS-2021-001-13" title="View on CDS"><img alt="ALICE,Inner Tracking System" src="//cds.cern.ch/images/ALICE-PHO-ITS-2021-001-13/file?size=large" /></a> <figcaption>Installation of the Outer Barrel of the new silicon Inner Tracking System of ALICE inside the solenoidal magnet.<span> (Image: CERN)</span></figcaption></figure><p>But the outer barrel was the easy part, at least compared to its inner counterpart whose insertion was complicated by its position right by the beam pipe. Luckily, weeks of rehearsals and careful alignment studies using metrological surveys proved their worth, and after an intense week of insertion and mating of the component’s two halves, which involved a few late-evening sessions for the experts, the delicate manoeuvre was completed in the late evening of 12 May. Preliminary tests showed no damage occurred during the installation, proving that the teams’ hard work paid off.</p> <p>The ITS is now fully ready for stand-alone tests with cosmic rays, in view of joining the MFT for a common commissioning phase. The final steps before taking data at the LHC are the installation scheduled for next month of the Fast Interaction Trigger, the last of the ALICE subdetectors that has yet to join this formidable machine, and an overarching commissioning phase starting in July. With the milestone of the ITS installation now behind them, the ALICE collaboration is looking ahead to Run 3 with growing confidence and excitement.</p> </div> Wed, 26 May 2021 07:29:23 +0000 thortala 157096 at https://home.cern AMS, a decade of cosmic discoveries https://home.cern/news/news/experiments/ams-decade-cosmic-discoveries <span>AMS, a decade of cosmic discoveries</span> <div class="field field--name-field-p-news-display-byline field--type-entity-reference field--label-hidden field--items"> <div class="field--item">Ana Lopes</div> </div> <span><span lang="" about="/user/159" typeof="schema:Person" property="schema:name" datatype="">abelchio</span></span> <span>Tue, 05/18/2021 - 16:57</span> <div class="field field--name-field-p-news-display-caption field--type-string-long field--label-hidden field--item">The AMS detector on the International Space Station (Image: NASA) </div> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>It’s been a decade in space for the <a href="https://home.cern/science/experiments/ams">Alpha Magnetic Spectrometer </a>(AMS) – and a decade of amazing cosmic discoveries. On its final flight on 16 May 2011, space shuttle Endeavour delivered the AMS detector, which was assembled at CERN, to the International Space Station. And by 19 May 2011 the detector was installed and sending data back to Earth – to NASA in Houston and then from NASA to CERN for analysis. Ten years and more than 175 billion <a href="https://home.cern/science/physics/cosmic-rays-particles-outer-space">cosmic rays</a> later, AMS has delivered scientific results that have changed and confounded our understanding of the origin of these particles and how they journey through space at almost the speed of light.</p> <p>Cosmic rays come in many species. They are mainly the atomic nuclei of hydrogen, that is, protons, but also include the nuclei of heavier elements as well as electrons and the <a href="https://home.cern/science/physics/antimatter">antimatter</a> counterparts of protons and electrons. And they fall into two main types: primary and secondary. Primary cosmic rays are mostly produced in supernovae explosions in the Milky Way and beyond, and they can travel for millions of years before reaching AMS. Secondary cosmic rays are created in interactions between the primary cosmic rays and the interstellar medium.</p> <p>AMS measures the properties of the cosmic rays that reach it to try and shed light on the origin of <a href="https://home.cern/science/physics/dark-matter">dark matter</a>, antimatter and cosmic rays as well as to explore new phenomena. Highlights from <a href="https://ams02.space/publications">the many AMS results obtained</a> in its first ten years include a <a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.120.021101">result</a> showing that the numbers, or more precisely the “fluxes”, of several types of secondary cosmic rays are all surprisingly identical to one another and very different from those of primary cosmic rays. AMS also reported an <a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.041102">analysis</a> of the flux of cosmic-ray positrons, the antimatter particles of electrons, indicating that at high energies these cosmic rays predominantly originate either from the annihilation of dark matter particles in space or from other cosmic sources such as fast-spinning stars called pulsars.</p> <p>Other highlights include a <a href="https://home.cern/news/news/physics/cosmic-rays-throw-surprises-again">result</a> showing that, contrary to expectations, primary cosmic rays have at least two distinct classes, one made of light nuclei and the other made of heavy nuclei. Intriguingly, however, a more <a href="https://home.cern/news/news/physics/ams-reveals-properties-iron-cosmic-rays">recent study</a> revealed that iron nuclei – the most abundant primary cosmic rays after silicon nuclei and the heaviest cosmic rays measured by AMS until now – belong unexpectedly not to the same class as the other heavy nuclei but instead to the class of light nuclei.</p> <p>“It’s impossible to do justice to all of the AMS results, but one thing is clear,” says AMS spokesperson Samuel Ting. “Over the past ten years, AMS has challenged time and again conventional theory of cosmic-ray origin and propagation, transforming our understanding of these cosmic particles.”</p> <p>AMS continues to collect data, following the successful completion of a <a href="https://www.youtube.com/watch?v=ogjUtZeoHOo">series of spacewalks</a> – unparalleled in complexity for a space intervention – that have extended its remaining lifetime to match that of the International Space Station. And if the results obtained in the past decade are anything to go by, more cosmic discoveries will no doubt be in store.</p> </div> Tue, 18 May 2021 14:57:40 +0000 abelchio 157053 at https://home.cern LS2 Report: Installation of the CMS beam pipe https://home.cern/news/news/experiments/ls2-report-installation-cms-beam-pipe <span>LS2 Report: Installation of the CMS beam pipe</span> <div class="field field--name-field-p-news-display-byline field--type-entity-reference field--label-hidden field--items"> <div class="field--item">Ali Karaki</div> </div> <span><span lang="" about="/user/151" typeof="schema:Person" property="schema:name" datatype="">anschaef</span></span> <span>Tue, 05/11/2021 - 12:47</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>After several years of complex design, manufacture and planning, the CMS collaboration, in close cooperation with experts from CERN’s Vacuum, Surfaces and Coating group (TE department), have in recent months been installing the new heart of the detector: the beam pipe. This fragile, 36-m-long component, in which the LHC beams collide at the Interaction Point, will be one of the last elements of the experiment to be installed before closing the detector.</p> <p>The design of the new beam pipe has to comply with the numerous demands of physics, vacuum and integration requirements. From either side of the Interaction Point, the cylindrical section of the central chamber, with a diameter of 43.4 mm, has been extended from 1.6 m to 3.1 m to be compatible with the Phase 2 Tracker sub-detector that will be installed during LS3.</p> <p>An important change with respect to the previous layout of the beam pipe consists in a new vacuum pumping group, moved away from the detector at 16 m from the Interaction Point, to facilitate maintenance.</p> <p>Another key motivation behind the beam pipe layout change is the reduction of the radiation dose received by personnel during interventions. The new aluminium alloy used for the beam pipe reduces the induced radioactivity by a factor of 5 compared to the stainless steel used for the old beam pipe. This alloy has been chosen as the main material of the experimental vacuum chambers for Run 3 and the HL-LHC era.</p> <p>After a series of acceptance tests, the vacuum chamber segments were equipped with a set of temperature sensors and then wrapped with heating foils, the so-called “bake-out jackets”, that will be used to heat up the beam pipe from ambient temperature to 230 °C after the installation. The bake-out will activate the non-evaporable getter (NEG) material already coating the inner surface of the vacuum chambers, which will act as a distributed vacuum pump, constantly absorbing any residual gas. This will clean up stray particles and help to achieve the ultra-high vacuum that is essential inside the beamline of any particle collider to prevent collisions between the circulating beam particles and residual gas molecules. Such collisions would scatter the beam, creating a noisy background for the detector and degrading the beam life.</p> <figure class="cds-image" id="CERN-PHOTO-202103-042-8"><a href="//cds.cern.ch/images/CERN-PHOTO-202103-042-8" title="View on CDS"><img alt="CMS,Beampipe,Detectors" src="//cds.cern.ch/images/CERN-PHOTO-202103-042-8/file?size=large" /></a> <figcaption>Installation of the optical fibres for monitoring the central segment of the new CMS vacuum chamber.<span> (Image: CERN)</span></figcaption></figure><p>Following a detailed installation sequence of the vacuum pipe segments, in parallel, at both ends of the experiment, the mechanical installation of the chambers and all their operational and temporary supports was completed at the end of April.</p> <figure class="cds-image" id="CERN-PHOTO-202103-040-39"><a href="//cds.cern.ch/images/CERN-PHOTO-202103-040-39" title="View on CDS"><img alt="Detectors,CMS,Beampipe" src="//cds.cern.ch/images/CERN-PHOTO-202103-040-39/file?size=large" /></a> <figcaption>Insertion of the central vacuum chamber across the CMS Tracker.<span> (Image: CERN)</span></figcaption></figure><p>With the mechanical installation completed, a global leak test will be performed on the chambers, with the aim of reaching an ultimate pressure of 10<sup>−11</sup> millibars. Then, the detector endcaps will be positioned in the bake-out configuration for a duration of 168 hours. A final step of ultra-pure neon injection will complete the activity, readying the new beam pipe for Run 3.</p> <p><iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="" frameborder="0" height="315" src="https://www.youtube.com/embed/vota8OytFuI" title="YouTube video player" width="560"></iframe></p> <p>_______</p> <p><em>This is an extract of an article published on the CMS website. You can read the full version <a class="bulletin" href="https://cms.cern/news/installation-beam-pipe-delicate-surgical-operation-heart-cms-experiment">here</a>.</em></p> </div> Tue, 11 May 2021 10:47:29 +0000 anschaef 157003 at https://home.cern A SciFi moment for the LHCb experiment https://home.cern/news/news/experiments/scifi-moment-lhcb-experiment <span>A SciFi moment for the LHCb 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">Ana Lopes</div> </div> <span><span lang="" about="/user/159" typeof="schema:Person" property="schema:name" datatype="">abelchio</span></span> <span>Thu, 05/06/2021 - 08:28</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>Its name may suggest it is the stuff of science fiction, but it’s not. SciFi – the new scintillating-fibre particle-tracking detector of the <a href="https://home.cern/science/experiments/lhcb">LHCb</a> experiment – is very real, and its first pieces have just journeyed 100 metres down to be installed in the underground cavern that houses the experiment. The construction of the detector and its installation in the LHCb cavern are part of the <a href="https://home.cern/news/news/experiments/transforming-lhcb-whats-store-next-two-years">ongoing upgrade work</a> that is transforming LHCb so it can sustain a fivefold increase in the rate of proton–proton collisions when the <a href="https://home.cern/science/accelerators/large-hadron-collider">Large Hadron Collider</a> starts up again in 2022.</p> <p>The scintillating-fibre detector is no ordinary particle detector. As the name indicates, the detector is made of scintillating fibres – optical fibres that emit light when a particle interacts with them. The fibres also contain additional scintillator dyes that shift the light’s wavelength from ultraviolet to blue-green, such that it can travel the length of the fibre and be recorded by devices called silicon photomultipliers, which convert the light to electrical signals.</p> <p>Such detector technology is not new, but it has had to be refined to achieve the scale and precision of the SciFi detector. Scientists had to painstakingly examine and wind more than 10 000 kilometres of fibre to produce the multi-layer ribbons needed for the detector modules – no mean feat.</p> <p>“It took more than a dozen partner institutes in nine different countries working together since 2014 to make SciFi a reality,” says Blake Leverington, who is coordinating the assembly of the 12 separate pieces that will make up the complete detector. “The lowering of the first four SciFi pieces into the LHCb cavern is an exciting and satisfying moment for us.”</p> <p>The remaining eight pieces are being assembled and will be installed before the LHC proton beams return in the spring of 2022. Watch this space for more milestones in the transformation of LHCb in time for the next LHC run.</p> <p>____</p> <p><em>Find out more about the SciFi detector in <a class="bulletin" href="https://home.cern/news/news/experiments/ls2-report-lhcb-looks-future-scifi-detector">this story</a>.</em></p> </div> Thu, 06 May 2021 06:28:43 +0000 abelchio 156949 at https://home.cern Supporting talented students with the ATLAS PhD Grant https://home.cern/news/news/experiments/supporting-talented-students-atlas-phd-grant <span>Supporting talented students with the ATLAS PhD Grant</span> <span><span lang="" about="/user/151" typeof="schema:Person" property="schema:name" datatype="">anschaef</span></span> <span>Tue, 05/11/2021 - 10:56</span> <div class="field field--name-field-p-news-display-body field--type-text-long field--label-hidden field--item"><p>The ATLAS PhD Grant is a flagship programme of the <a href="https://giving.web.cern.ch/">CERN &amp; Society Foundation</a>. It was established in 2013 by former ATLAS spokespersons Fabiola Gianotti and Peter Jenni, using their award money from the <a href="https://breakthroughprize.org/Prize/1">Breakthrough Prize in Fundamental Physics</a>. In 2014, the first batch of students began their grant periods. Now in its eighth year, the ATLAS PhD Grant relies on private contributions through the CERN &amp; Society Foundation to continue its legacy.</p> <p>Due to the ongoing global pandemic, this year’s award ceremony was broadcast live on Facebook and LinkedIn, with CERN &amp; Society donors and members of the CERN Management joining in remotely. The recipients of the 2021 ATLAS PhD Grant were announced as <strong>Ana Luisa Carvalho</strong> (LIP, Portugal) and <strong>Humphry Tlou</strong> (University of the Witwatersrand, South Africa). These talented and motivated students will receive 1.5 years of funding for their studies at CERN, under the supervision and training of ATLAS collaboration experts.</p> <p>“When Fabiola Gianotti and I received the Fundamental Physics Prize, it was clear to us that we wanted to give something back to ATLAS,” said Peter Jenni, speaking at the event. “We remembered our own time as students at CERN and wanted to give others the same opportunity. CERN is a great learning environment – not just for physics, but to experience working closely with people from different countries and cultures.”</p> <p>_____</p> <p><em>Ana Luisa Carvalho and Humphry Tlou each gave a short speech of thanks, extracts of which can be read in the full version of the article <a class="bulletin" href="https://cernandsocietyfoundation.cern/news/supporting-talented-students-atlas-phd-grant">here</a>. You can also <a href="https://www.facebook.com/watch/?v=1497526380592347">watch a recording of the full ceremony</a> or visit the <a href="https://cernandsocietyfoundation.cern/">CERN &amp; Society website</a> to learn more about the ATLAS PhD Grant.</em></p> </div> Tue, 11 May 2021 08:56:58 +0000 anschaef 156998 at https://home.cern