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  • richardmitnick 2:37 pm on May 11, 2019 Permalink | Reply
    Tags: "How an episode of ‘Chopped’ led to a fix for future particle accelerators", Fermilab scientist designs innovative spun-sugar electrospinning technique, , FNAL LBNF/ DUNE,   

    From University of Chicago: “How an episode of ‘Chopped’ led to a fix for future particle accelerators” 

    U Chicago bloc

    From University of Chicago

    May 10, 2019
    Caitlyn Buongiorno

    Fermilab scientist designs innovative spun-sugar electrospinning technique.


    1
    In electrospinning, a positive charge is applied to liquidized material to create thin strands that eventually harden into a solid, fibrous material. Photo by Reidar Hahn

    Bob Zwaska, a scientist at the UChicago-affiliated Fermi National Accelerator Laboratory, was watching a contestant on the cooking show Chopped spin sugar for their dessert when he realized the same principle might be applicable to accelerator targets.

    The technique he spun out of the idea could hugely boost the power at which future particle accelerators could operate—helping us unlock the secrets of how our universe is built.

    One of the ways particle accelerators produce particles is by firing particle beams at targets. These targets are stationary, solid blocks of material, such as graphite or beryllium. When the beam collides with the target, it produces a spray of particles that can inform scientists about the fundamental building blocks of the universe.

    For example, the pioneering international Deep Underground Neutrino Experiment, or DUNE, an experiment hosted by Fermilab and developed in collaboration with more than 170 institutions worldwide, seeks to understand why matter exists in the universe by unlocking the mysteries of ghostly particles called neutrinos.

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    But the experiment is limited by how much the targets can handle; to solve these mysteries, the accelerator beam used by DUNE needs to reach a power of at least 1.2 megawatts—twice the amount current targets can handle.

    The point of collision between the beam and the target—an area significantly smaller than the target itself, varying between the size of an ant and the graphite in a mechanical pencil—as rapidly and repeatedly heated to above 500 degrees Celsius. This heat causes that tiny area to try to expand, but because the currently used targets are solid, there’s no room for expansion. Instead, the hot spot pushes against the surrounding area over and over again, like a jackhammer. This has the potential to damage the target.

    When you dive into a pool, your collision with the water causes waves to ripple across the surface. When the waves reach the edge of the pool, they will rebound and cross over other waves, either destroying each other or combining to make a larger wave. In a pool, if a wave gets too large, the water can simply splash over the edge. In a solid target, however, if a wave gets too big, the material will crack.

    At the Fermilab particle accelerator’s current beam intensities, this isn’t a problem, because targets can withstand the resulting waves for a long time. As Fermilab upgrades its accelerator complex and the intensity increases, that endurance time drops drastically.

    “Worldwide, there is a push for higher-intensity machines to create rare particles. These targets have sometimes been the sole limiting factor in the performance of such facilities,” Zwaska said. “So, to research areas of new physics, we have to be pushing for new technologies to confront this problem.”

    A new spin

    Tasked with coming up with an alternative target to use in high-powered accelerators, like the ones that will send beam to DUNE, Zwaska envisioned a target that consists of many twists and turns to prevent any wave buildup. This sinuous target would also be strong and solid at the microscale.

    He first tested graphite ropes, 3-D-printed fibers, and mostly hollow, reticulated solids before he stumbled upon the spun-sugar concept, which led him to electrospinning.

    First proposed in the early 1900s to produce thinner artificial silk, electrospinning has been used for air filtration in cars, wound dressing and pharmaceutical drugs. Like spinning sugar, electrospinning involves using a liquidized material to create thin strands that eventually harden into the desired structure. Instead of heating the liquid, electrospinning applies a positive charge to it. The charge on the liquid creates an attraction between it and a neutral plate, placed some distance away. This attraction stretches the material towards the plate, creating a solid, fibrous material.

    For accelerator targets, specialists turn metal or ceramic into a solid but porous material that consists of thousands of fiber strands less than a micrometer in diameter. That’s less than a hundredth the thickness of an average human hair, and about a third of a spider’s webbing.

    When the particle beam collides with an electrospun target, the fibers won’t propagate any waves. The lack of potentially material-damaging waves means that these targets can withstand much higher beam intensity.

    Instead of a pool, imagine you jump into a ball pit. Your collision will disrupt the arrangement of the balls immediately around you but leave the surrounding ones alone. The electrospun target acts the same way. The process leaves space between each fiber, allowing the fibers to expand uniformly, avoiding the jackhammer effect.

    Targeting better systems

    While this new technology potentially solves many of the issues with current targets, it has its own obstacles to overcome. Typically, the process to make an electrospun target takes days, with experts frequently having to stop to correct complications in the way the material accumulates.

    Sujit Bidhar, a postdoctoral researcher at Fermilab, is trying to address these issues. Bidhar is developing and testing methods that increase the number of fiber spin-off points that form at a single time, produce a thicker nanofiber target, and decrease the amount of electricity needed to create the positive charge. These advancements would both speed up and simplify the process.

    While he’s still trying different electrospinning techniques, Bidhar has already developed a new patent-pending electrospinning system, including a novel power supply.

    Bidhar’s electrospinning unit is more compact, more lightweight, simpler and cheaper than most conventional units.

    It’s also much safer to use due to its limited output power. Present commercial power supplies put out an amount of electric power that far exceeds what is needed to make electrospun targets. Bidhar’s power supply unit reduces the electric power output and overall unit size by half, which also makes it safer to use.

    “Medical personnel would be able to use this power supply to create biodegradable wound dressings in remote and mobile locations, without a bulky and high-voltage unit,” Bidhar said.

    Electrospun targets, like Bidhar’s power supply, could innovate the future of particle physics accelerators, allowing experiments such as DUNE to reach higher levels of beam intensity. These higher intensity beams will aid scientists in solving the enduring mysteries of astrophysics, nuclear physics and particle physics.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Chicago Campus

    An intellectual destination

    One of the world’s premier academic and research institutions, the University of Chicago has driven new ways of thinking since our 1890 founding. Today, UChicago is an intellectual destination that draws inspired scholars to our Hyde Park and international campuses, keeping UChicago at the nexus of ideas that challenge and change the world.

    The University of Chicago is an urban research university that has driven new ways of thinking since 1890. Our commitment to free and open inquiry draws inspired scholars to our global campuses, where ideas are born that challenge and change the world.

    We empower individuals to challenge conventional thinking in pursuit of original ideas. Students in the College develop critical, analytic, and writing skills in our rigorous, interdisciplinary core curriculum. Through graduate programs, students test their ideas with UChicago scholars, and become the next generation of leaders in academia, industry, nonprofits, and government.

    UChicago research has led to such breakthroughs as discovering the link between cancer and genetics, establishing revolutionary theories of economics, and developing tools to produce reliably excellent urban schooling. We generate new insights for the benefit of present and future generations with our national and affiliated laboratories: Argonne National Laboratory, Fermi National Accelerator Laboratory, and the Marine Biological Laboratory in Woods Hole, Massachusetts.

    The University of Chicago is enriched by the city we call home. In partnership with our neighbors, we invest in Chicago’s mid-South Side across such areas as health, education, economic growth, and the arts. Together with our medical center, we are the largest private employer on the South Side.

    In all we do, we are driven to dig deeper, push further, and ask bigger questions—and to leverage our knowledge to enrich all human life. Our diverse and creative students and alumni drive innovation, lead international conversations, and make masterpieces. Alumni and faculty, lecturers and postdocs go on to become Nobel laureates, CEOs, university presidents, attorneys general, literary giants, and astronauts.

     
  • richardmitnick 4:27 pm on April 5, 2019 Permalink | Reply
    Tags: "MINERvA successfully completes its physics run", , , FNAL LBNF/ DUNE, , , Neutrinos could hold the answer to one of the most pressing mysteries in physics: why matter was not completely annihilated by antimatter after the Big Bang., ,   

    From Fermi National Accelerator Lab: “MINERvA successfully completes its physics run” 

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    From Fermi National Accelerator Lab , an enduring source of strength for the US contribution to scientific research world wide.

    April 5, 2019
    Caitlyn Buongiorno

    FNAL MINERvA front face Photo Reidar Hahn

    On Feb. 26, a crowd of engineers, technicians and analysts crowded around a computer screen as Fermilab scientist Deborah Harris pressed “stop” on the data collection for the MINERvA neutrino experiment.

    “We’re all just really excited by what we’ve accomplished,” said Harris, MINERvA co-spokesperson and future professor at York University. “The detector worked wonderfully, we collected the data we need, and we did it on schedule.”

    MINERvA studies how neutrinos and their antimatter twins, antineutrinos, interact with the nuclei of different atoms. Scientists use that data to help discover the best models of these interactions. Now, after nine years of operation, the data taking has come to an end, but the analysis will continue for a while. MINERvA scientists have published more than 30 scientific papers so far, with more to come. As of today, 58 students have obtained their master’s or Ph.D. degrees doing research with this experiment.

    Neutrinos could hold the answer to one of the most pressing mysteries in physics: why matter was not completely annihilated by antimatter after the Big Bang. That imbalance from 13.7 billion years ago led the universe to develop into what we see today. Studying neutrinos (and antineutrinos) could uncover the mystery and help us understand why we are here at all.

    1
    The MINERvA collaboration gathers to celebrate the end of data taking. MINERvA co-spokesperson Laura Fields, kneeling at center, holds a 3-D-printed model of the MINERvA neutrino detector. Photo: Reidar Hahn

    A number of neutrino experiments investigate this mystery, including Fermilab’s NOvA experiment and the upcoming international Deep Underground Neutrino Experiment, hosted by Fermilab.

    FNAL/NOvA experiment map


    FNAL NOvA Near Detector

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA


    FNAL DUNE Argon tank at SURF


    SURF DUNE LBNF Caverns at Sanford Lab

    To be as successful as possible, these experiments need precise models that describe what happens before and after a neutrino collides with an atom.

    Every time a neutrino collides with part of an atom inside a detector, a spray of new particles flies off and travels through the rest of the detector. In order to understand the nuances of neutrinos, scientists need to know the energy of the neutrino when it first enters the detector and the energy of all the particles produced after the interaction. This task is complicated by the fact that some of the outgoing particles are invisible to the detector — and must still be accounted for.

    Imagine you’re playing pool and you shoot the cue ball at another ball. You can easily predict where that second ball will go. That prediction, however, gets much more complex when your cue ball strikes a collection of balls. After the break shot, they scatter in all directions, and it’s hard to predict where each will go. The same thing is true when a neutrino interacts with a lone particle: You can easily predict where the lone ball will go. But when a neutrino interacts with an atom’s nucleus — a collection of protons and neutrons — the calculation is much more difficult because, like the pool balls, particles may go off in many different directions.

    “It’s actually worse than that,” said Kevin McFarland, former MINERvA co-spokesperson and professor of physics at the University of Rochester. “All the balls in the break shot are also connected by springs.”

    MINERvA provides a neutrino-nucleus interaction guidebook for neutrino researchers. The experiment measured neutrino interactions with polystyrene, carbon, iron, lead, water and helium. Without MINERvA’s findings, researchers at other experiments would have a much tougher time understanding the outcomes of these interactions and how to interpret their data.

    “I really am proud of what we’ve been able to accomplish so far,” said Laura Fields, Fermilab scientist and co-spokesperson for MINERvA. “Already the world has a much greater understanding of these interactions.”

    See the full article here.


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    FNAL Icon

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world collaborate at Fermilab on experiments at the frontiers of discovery.

    FNAL MINERvA front face Photo Reidar Hahn

    FNAL DAMIC

    FNAL Muon g-2 studio

    FNAL Short-Baseline Near Detector under construction

    FNAL Mu2e solenoid

    Dark Energy Camera [DECam], built at FNAL

    FNAL DUNE Argon tank at SURF

    FNAL/MicrobooNE

    FNAL Don Lincoln

    FNAL/MINOS

    FNAL Cryomodule Testing Facility

    FNAL MINOS Far Detector in the Soudan Mine in northern Minnesota

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    FNAL/NOvA experiment map

    FNAL NOvA Near Detector

    FNAL ICARUS

    FNAL Holometer

     
  • richardmitnick 9:08 am on March 28, 2019 Permalink | Reply
    Tags: , , , , FNAL LBNF/ DUNE, ,   

    From Fermi National Accelerator Lab: “Waiting for neutrinos” 

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    From Fermi National Accelerator Lab , an enduring source of strength for the US contribution to scientific research world wide.

    March 26, 2019
    Jim Daley

    On Feb. 24, 1987, light from a supernova that exploded 168,000 years ago in the Large Magellanic Cloud, a neighbor of the Milky Way, reached Earth.

    Large Magellanic Cloud. Adrian Pingstone December 2003

    Astronomers Ian Shelton and Oscar Duhalde at the Las Campanas Observatory in Chile first reported the supernova, called SN 1987A (or simply 87A), which was one of the brightest in nearly four centuries.

    SN1987a fromNASA/ESA Hubble Space Telescope in Jan. 2017 using its Wide Field Camera 3 (WFC3).

    Carnegie Las Campanas Observatory in the southern Atacama Desert of Chile in the Atacama Region approximately 100 kilometres (62 mi) northeast of the city of La Serena,near the southern end and over 2,500 m (8,200 ft) high

    A supernova such as 87A occurs when a star many times larger than our sun runs out of fuel in its core. At this point, the core is made of iron, and its fate hinges on the battle between two forces: Gravity tries to collapse it while electrons effectively repel each other, thanks to the Pauli exclusion principle, a quantum-mechanical effect. For a while, equilibrium is maintained, but the mass of the iron core keeps increasing, because of nuclear burning in the shell above it. Eventually, the core mass reaches a critical value called the Chandrasekhar limit, and the relentless pull of gravity wins. The core collapses on itself in near free fall, and a shockwave forms around it. Heated by the energy of escaping neutrinos, the shockwave ejects the outer layers of the star in a catastrophic blast that can briefly shine more brightly than entire galaxies. After losing its energy to neutrino emission, the core finally settles into what is known as a neutron star, effectively a giant nucleus made primarily of neutrons.

    By the time Duhalde and Shelton saw light from 87A, three neutrino detectors around the world had already picked up evidence of the supernova. Most of the energy released in a supernova is emitted as neutrinos, nearly massless subatomic particles that react rarely with ordinary matter. Because they are so weakly interacting, neutrinos can slip out of the envelope of a collapsing supernova hours before particles of light, which ride the explosion’s shockwave, are ejected.

    Neutrinos produced by 87A arrived on Earth just before the light from the explosion did. Irvine-Michigan-Brookhaven (IMB), a neutrino observatory in Ohio on the shore of Lake Erie, detected eight neutrino events.

    Irvine–Michigan–Brookhaven (detector) located in a Morton Salt company’s Fairport mine on the shore of Lake Erie in the United States 600 meters underground

    Baksan Neutrino Observatory in Russia detected five more, and Kamiokande II, a neutrino detector deep underground in a Japanese mine, saw 11.

    INR RAS – Baksan Neutrino Observatory (BNO). The Underground Scintillation Telescope in Baksan Gorge at the Northern Caucasus
    (Kabarda-Balkar Republic)

    Kamiokande-II operated 1985-1990

    It was the first time that neutrinos from a supernova had been detected – although the neutrino scientists didn’t realize it until after Duhalde and Shelton announced their observation. They found the neutrino events in their data only when they looked for them upon hearing the news about the supernova.

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    A supernova is born when the burnt out stellar core collapses, releasing a shockwave, which speeds toward the outer layers of the star. Most of the energy released in a supernova is emitted as neutrinos, nearly massless subatomic particles that react rarely with ordinary matter. Image: Max Planck Institute for Astrophysics

    Max Planck Institute for Astrophysics

    Something incredible waiting to be known?

    More than 30 years later, scientists are building the international Deep Underground Neutrino Experiment (DUNE), hosted by Fermilab.

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA


    FNAL DUNE Argon tank at SURF


    SURF DUNE LBNF Caverns at Sanford Lab

    Its 70,000-ton liquid-argon detector will be located almost a mile underground at Sanford Underground Research Facility [SURF] in South Dakota, waiting for another burst of supernova neutrinos to arrive.

    The discovery would portend a new exploding star somewhere in the Milky Way.

    Kate Scholberg, a particle physicist at Duke University, says supernova neutrinos could teach us a lot about supernovae and particle physics if we detect them the next time an event like 87A occurs. That’s because the neutrinos carry information about the supernova with them as they travel across space. The signals the neutrinos make in particle detectors like DUNE would allow physicists to draw conclusions about the conditions in which the neutrinos were made and provide evidence for the fate of the exploding star.

    “You can actually see the processes that are happening in real time as the neutron star is being born,” said Scholberg, who studies neutrinos as part of DUNE.

    These processes could point to new physics. For example, if exotic particles are produced in a supernova, traces of their existence would be apparent in the signal made by the neutrinos. That’s because physicists can calculate the total energy produced by a supernova, and they can estimate how much of it was emitted as neutrinos from the measurement. If the total energy detected doesn’t add up to the total expected, it could hint at new particles being produced.

    “The detection of a supernova in 1987 from Kamiokande was, to me, one of the most impressive detections for particle physics,” said Inés Gil Botella, a scientist at Spain’s Center for Energy, Environment and Technology, or CIEMAT, and one of the leads on DUNE’s supernova search. “It opened a way to understanding the universe through particles other than photons. This new multimessenger era of astrophysics really started with the detection of supernova neutrinos.”

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    A supernova’s shockwave ejects the outer layers of the star in a catastrophic blast that can briefly shine more brightly than entire galaxies. Image: NASA

    The DUNE dimension

    While detectors captured only 24 of the neutrinos emitted from 87A, hundreds of peer-reviewed papers were published as a result of the discovery and subsequent research. When DUNE is completed, it could see far more neutrinos and contribute to a similar – and entirely novel – flurry of research.

    “DUNE has several capabilities that are truly unique among all large neutrino detectors when it comes to studies of supernova neutrinos,” said Steven Gardiner, a Fermilab scientist who works on simulating what occurs when a supernova neutrino enters a detector.

    DUNE is different from Cherenkov detectors such as Kamiokande in several ways, including that it uses liquid argon instead of water as the target medium. Liquid-argon detectors spot neutrinos when they collide with argon nuclei. Argon’s nucleus is composed of protons and neutrons that are arranged in various energy states. When a neutrino collides with an argon nucleus, a proton or neutron in a lower energy state can be elevated to a higher energy state and lead to the emission of particles from the argon nucleus via its de-excitation. Some of these particles can be observed by the detector.

    “When the nucleus de-excites, a few different things can happen,” Gardiner said. “The nucleus can emit gamma rays, neutrons, protons or heavier nuclear fragments. You can potentially see gamma rays in liquid argon, because they’ll scatter electrons in the argon, and you’ll see little blips that come from them.”

    Cherenkov detectors, which look primarily for electron antineutrinos striking bare protons, can’t reconstruct gamma rays with as much detail as liquid-argon detectors can.

    Because of the complicated nature of the energy reconstruction, it’s quite a challenge to reconstruct supernova neutrino events in a liquid-argon detector. Gardiner is currently building computer simulations that can model the various signatures that can occur when a neutrino interacts with the liquid argon in DUNE.

    “The difficulty is, because you have so many argon excited states available, you have all sorts of different signatures that could be produced in your detector,” he said. “And you have to deal with that level of complexity to fully reconstruct the energy from a neutrino collision.”

    Then there’s the challenge of teasing out the signal from the noise. Supernova neutrinos carry far less energy than, say, neutrinos produced by a particle accelerator, so the signals they produce in the argon are weaker. Unearthing these low-energy interactions requires both a sensitive detector and a knowledge of the interaction’s various signatures.

    “High-energy neutrinos are easier to detect, and their interactions are well-known. We know how they behave,” Gil Botella said. “But at these low, supernova-neutrino energies, the interactions with argon are not very well-known. We don’t have much experimental data to say what happens when a low-energy neutrino interacts with argon.”

    And scientists at the world’s other neutrino projects are looking to change that, planning experiments that would paint a clearer picture of low-energy neutrinos.

    “Studying neutrinos is a tricky business, and we have more work to do, but DUNE’s technological capabilities make those challenges far more tractable,” Gardiner said. “The physics payoffs will be huge. If we’re going to tackle these questions, DUNE is a good way to do it.”

    FNAL DUNE can capture neutrinos from supernovae

    Oscillation station

    DUNE could also help inform our understanding of neutrino oscillation in a way that other detectors cannot. In Cherenkov detectors, the signal is produced mostly by electron antineutrinos interacting with water molecules. Conversely, liquid argon also samples electron neutrinos from the supernova’s ejecta.

    “We need both electron neutrinos and antineutrinos to disentangle oscillation scenarios,” said Alex Friedland, a particle physicist and senior staff scientist at SLAC National Accelerator Laboratory in California. DUNE, because it will be the only detector that can see electron neutrinos, adds a missing piece to that puzzle.

    Neutrinos oscillate between three flavors (electron, muon or tau) as they move through space. Physicists have studied neutrino oscillations in neutrinos produced in the sun, in ­­Earth’s atmosphere, from nuclear reactors and in high-energy particle beams created by particle accelerators. But they haven’t been able to study them in supernovae, where the number of neutrinos produced is simply off the charts compared to other sources.

    “This is the ultimate intensity frontier,” Friedland said. “Nature does it for us, so we just have to take advantage of that. The supernova is a laboratory on the other side of the galaxy. It carries out experiments, and we ‘just’ have to build the detector and make a measurement. Of course, it’s useful to keep in mind that this measurement ‘just’ happens to be one of the most challenging tasks that DUNE, the most advanced neutrino detector ever built, will undertake.”

    Neutrino oscillation typically describes a single particle changing flavors, but under the right circumstances — such as in a collapsing supernova — many neutrinos can oscillate collectively.

    “Collective oscillation means that you have neutrinos that go through the background of other neutrinos, and a flavor state of a given neutrino knows about what all the other neutrinos that it passes are doing in terms of flavor,” Friedland said.

    With enough neutrino signals – which a detector such as the giant DUNE could amass – physicists can reconstruct the energy spectrum of the electron neutrinos arriving at Earth. This spectrum can have striking features imprinted on it by collective oscillations of neutrinos inside the supernova. With that information, they can see how the neutrinos evolved collectively in the dying star.

    The information can give them clues about what happened to the star itself, as well. The neutrino density is so high in a core-collapse supernova like 87A that it affects how the star explodes. The shockwave of the explosion is propelled by what physicists call the neutrino-driven wind.

    Other core-collapse events might not produce a supernova that we can see easily from Earth, but we’ll know they occurred when the neutrino detectors register a burst.

    “When a star collapses into a black hole, you likely don’t get any fireworks,” Scholberg explained. “The observers might see nothing, or just see a star wink out. Those kinds of events would be seen brightly in neutrinos.”

    Once the DUNE detectors are in place, they’ll be used to take measurements of neutrinos coming from Fermilab accelerators and wait patiently for a supernova to explode. This happens in our galaxy on average once every 30 to 50 years.

    “That’s the drawback of the supernova neutrino world; we’re always waiting,” Scholberg said. “You better not miss anything.”

    When it does occur, a core-collapse supernova will be a major event that will affect multiple fields of research, including particle physics and astrophysics.

    “It’s so impressive: Supernovae produce a huge number of neutrinos, they travel such a long distance, and you get a signal directly from something that’s kiloparsecs away,” Gil Botella said. “It’s really amazing to get access to information inside a star like that. It’s the connection with the objects in the universe — the unknown of the universe.”

    Members of the public can sign up to receive alerts from the SuperNova Early Warning System (SNEWS). The automated system currently includes seven neutrino experiments in Canada, China, Italy, Japan and at the South Pole. When neutrinos produced in a supernova reach Earth, SNEWS will send out email alerts to announce their arrival, which would captivate the research community.

    “Once the supernova happens, you can forget about everything else that we were thinking about,” Friedland said. “The world of science will be talking about that for at least a year or more.”

    The Deep Underground Neutrino Experiment is supported in part by the U.S. Department of Energy Office of Science.

    See the full article here.


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    FNAL Icon

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world collaborate at Fermilab on experiments at the frontiers of discovery.

    FNAL MINERvA front face Photo Reidar Hahn

    FNAL DAMIC

    FNAL Muon g-2 studio

    FNAL Short-Baseline Near Detector under construction

    FNAL Mu2e solenoid

    Dark Energy Camera [DECam], built at FNAL

    FNAL DUNE Argon tank at SURF

    FNAL/MicrobooNE

    FNAL Don Lincoln

    FNAL/MINOS

    FNAL Cryomodule Testing Facility

    FNAL MINOS Far Detector in the Soudan Mine in northern Minnesota

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    FNAL/NOvA experiment map

    FNAL NOvA Near Detector

    FNAL ICARUS

    FNAL Holometer

     
  • richardmitnick 1:10 pm on March 15, 2019 Permalink | Reply
    Tags: , , , FNAL LBNF/ DUNE, , , ,   

    From Fermi National Accelerator Lab: “Fermilab, international partners break ground on new state-of-the-art particle accelerator” 

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    From Fermi National Accelerator Lab , an enduring source of strength for the US contribution to scientific research world wide.

    March 15, 2019
    Andre Salles, Fermilab Office of Communication
    asalles@fnal.gov
    630-840-6733

    With a ceremony held today, the U.S. Department of Energy’s Fermi National Accelerator Laboratory officially broke ground on a major new particle accelerator project that will power cutting-edge physics experiments for many decades to come.

    The new 700-foot-long linear accelerator, part of the laboratory’s Proton Improvement Plan II (PIP-II), will be the first accelerator project built in the United States with significant contributions from international partners. When complete, the new machine will become the heart of the laboratory’s accelerator complex, vastly improving what is already the world’s most powerful particle beam for neutrino experiments and providing for the long-term future of Fermilab’s diverse research program.

    The new PIP-II accelerator will make use of the latest superconducting technology, a key research area for Fermilab. Its flexible design will enable it to work as a new first stage for Fermilab’s chain of accelerators, powering both the laboratory’s flagship project — the international Deep Underground Neutrino Experiment (DUNE), hosted by Fermilab — and its extensive suite of on-site particle physics experiments, including searches for new particles and new forces in our universe.

    1
    On Friday, March 15, Fermilab broke ground on the PIP-II accelerator project, joined by dignitaries from the United States and international partners on the project. From left: Senator Tammy Duckworth (IL), Senator Dick Durbin (IL), Rep. Sean Casten (IL-6), Rep. Robin Kelly (IL-2), Rep. Bill Foster (IL-11), Fermilab Director Nigel Lockyer, Rep. Lauren Underwood (IL-14), Illinois Governor JB Pritzker, DOE Under Secretary for Science Paul Dabbar, PIP-II Project Director Lia Merminga, DOE Associate Director for High Energy Physics Jim Siegrist, University of Chicago President Robert Zimmer, Consul General of India Neeta Bhushan, British Consul General John Saville, Consul General of Italy Giuseppe Finocchiaro, Consul General of France Guillaume Lacroix, DOE Fermi Site Office Manager Mike Weis, DOE PIP-II Federal Project Director Adam Bihary and Consul General of Poland Piotr Janicki. Photo: Reidar Hahn

    DUNE is under construction now and will be the most advanced experiment in the world studying ghostly, invisible particles called neutrinos. These particles may hold the key to cosmic mysteries that have baffled scientists for decades. The DUNE collaboration brings together more than 1,000 scientists from over 180 institutions in more than 30 countries, all with a single goal: to better understand these elusive particles and what they can tell us about the universe.

    The PIP-II accelerator will enable the beam that will send trillions of neutrino particles 800 miles (1,300 kilometers) through the earth to the four-story-high DUNE detector, to be built a mile beneath the surface at the Sanford Underground Research Facility [SURF] in Lead, South Dakota. With the improved particle beam enabled by PIP-II, scientists will use the DUNE detector to capture the most vivid 3-D images of neutrino interactions ever seen.

    3
    Shortly after breaking ground on the PIP-II accelerator project on Friday, March 15, Fermilab employees were joined by the governor of Illinois, six members of Congress and partners from around the world in this group photo. Photo: Reidar Hahn

    PIP-II is itself a groundbreaking scientific instrument, and its construction is pioneering a new paradigm for accelerator projects supported by DOE. The accelerator would not be possible without the contributions and world-leading expertise of partners in France, India, Italy and the UK. Scientists in each country are building components of the accelerator, to be assembled at Fermilab. This will be the first accelerator project in the United States completed using this approach.

    With PIP-II at the center of the laboratory’s accelerator complex, Fermilab will remain at the forefront of particle physics research and accelerator science for the foreseeable future.

    Today’s groundbreaking ceremony for the PIP-II accelerator was attended by dignitaries from around the globe. Speakers included Sen. Dick Durbin (IL), Sen. Tammy Duckworth (IL), Rep. Lauren Underwood (IL-14), Rep. Bill Foster (IL-11), Rep. Robin Kelly (IL-2), Rep. Sean Casten (IL-6), DOE Under Secretary for Science Paul Dabbar, University of Chicago President Robert Zimmer, and national and international partners in the project.

    4
    This architectural rendering shows the buildings that will house the new PIP-II accelerators. Architectural rendering: Gensler. Image: Diana Brandonisio.

    See the full article here .


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    FNAL Icon

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.

    FNAL MINERvA front face Photo Reidar Hahn

    FNAL DAMIC

    FNAL Muon g-2 studio

    FNAL Short-Baseline Near Detector under construction

    FNAL Mu2e solenoid

    Dark Energy Camera [DECam], built at FNAL

    FNAL DUNE Argon tank at SURF

    FNAL/MicrobooNE

    FNAL Don Lincoln

    FNAL/MINOS

    FNAL Cryomodule Testing Facility

    FNAL MINOS Far Detector in the Soudan Mine in northern Minnesota

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    FNAL/NOvA experiment map

    FNAL NOvA Near Detector

    FNAL ICARUS

    FNAL Holometer

     
  • richardmitnick 12:09 pm on January 25, 2019 Permalink | Reply
    Tags: , , FNAL LBNF/ DUNE, , ,   

    From Symmetry: “Success after a three-year sprint” 

    Symmetry Mag
    From Symmetry

    01/25/19
    Lauren Biron

    1
    Photo by CERN

    After a rush to start up the first large prototype detector, stellar results show the technology for the Deep Underground Neutrino Experiment is ready to shine.

    When scientists plan to build a new particle detector, they run simulations to get a picture of what the particle interactions will look like. After constructing and starting up the real thing, they expect a period of tuning, adjusting, fiddling, and fixing to get things running smoothly. They normally don’t expect to turn the detector on and see particle tracks of a quality that exceeds their idealized simulations, especially when it is a prototype detector.

    And then there is ProtoDUNE.

    “It was fantastic, with neater tracks and less noise from electronics than we expected,” says Flavio Cavanna, a scientist at the US Department of Energy’s Fermilab and the co-coordinator for the first ProtoDUNE detector that came to life this fall. “The entire technology operated as we wanted it to, which is beyond what one can dream.”

    The Deep Underground Neutrino Experiment (DUNE) is an international endeavor to unlock the mysteries of particles called neutrinos, which could hold the key to one of the biggest unsolved mysteries in physics: why matter exists in the universe.

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    While the DUNE detector modules ultimately will be 20 times larger, this first prototype detector, ProtoDUNE-SP, is still the largest liquid-argon neutrino detector ever brought to life – and a crucial step in making sure DUNE will work as expected.

    For Cavanna and hundreds of others from DUNE institutions in North America, Latin America, Europe, and Asia, these exceptional results are the culmination of three years of hard work and fitful nights. In that short stretch of time, an international team of people had to coalesce; transform a chunk of land into an experimental facility; construct buildings, infrastructure, and an enormous cryogenic container; and design and fabricate the pieces for a house-sized detector that would be assembled inside of that container like a ship in a bottle.

    “You build a detector, but never know if it really works until you see the first track,” says Roberto Acciarri, assembly and run coordinator for the detector at CERN, the European Center for Nuclear Research. “You always have that small doubt inside your heart: Is this really going to work?”

    A late-night phone call

    In December 2015, Cavanna was in Japan for work. One night, he received a call from Fermilab’s director asking if he would like to be a coordinator on a new detector. Only a few things at the time were certain, Cavanna says.

    First, the new experiment had been approved by CERN and Fermilab, and CERN agreed that it could live at the Neutrino Platform, a brand-new experimental facility. The detector would use argon, an element found in the air we breathe that becomes a liquid at very cold temperatures. It would serve as one of two test beds (both called ProtoDUNE) for technologies to be used in the Fermilab-hosted Deep Underground Neutrino Experiment.

    Second, while many institutions from around the world had formally signed on to participate in DUNE, a full-fledged scientific community dedicated to ProtoDUNE had yet to be identified and organized – and was essential to building a detector of such huge size and scope.

    Finally, there was a looming deadline: The detector ideally would be up and running before the start of the long shutdown of the particle accelerator complex at CERN in fall 2018. This was the only way the team could use CERN’s proton beam to make additional measurements in the detector.

    “The schedule was tight,” says Fermilab scientist Gina Rameika, the construction coordinator for ProtoDUNE. “Everyone knew the schedule was almost impossible. We had to get it installed and buttoned up in order to get it filled [with liquid argon] and take beam.”

    So they got to work.

    Build it bigger

    Putting together the world’s biggest liquid-argon detector required smart minds and helping hands. The first step was identifying and convincing scientists and engineers willing to make ProtoDUNE-SP the center of their world for the coming three years, working together as a global team.

    “DUNE is conceived and set up as an international project. It’s planetary,” Cavanna says. People signed on to ProtoDUNE-SP from institutions in North America, Europe, Latin America, and Asia. “ProtoDUNE was a prototype of DUNE technologically, but also from this collaborative structure perspective.”

    Of course, ProtoDUNE-SP is not the first liquid-argon detector ever constructed. The technology was pioneered at the large scale for the ICARUS detector, which ran from 2010 to 2013 at the Italian National Institute of Nuclear Physics’ Gran Sasso National Laboratory under the leadership of Nobel laureate Carlo Rubbia. The team could also look to other liquid-argon experiments, such as MicroBooNE and LArIAT at Fermilab.

    FNAL/ICARUS

    FNAL/MicroBooNE

    Fermilab LArIAT

    “We had a solid foundation from previous efforts, but DUNE will take liquid-argon technology to the yet unexplored multi-kiloton scale,” says CERN’s Francesco Pietropaolo, convener of the ProtoDUNE high-voltage consortium. “We knew ProtoDUNE would be essential for us to test new technologies and see how we could scale up to the much larger volume needed for DUNE.”

    As groups around the globe made design decisions and mock-ups and eventually started fabricating their individual pieces, construction got under way at CERN, with Marzio Nessi as the head of CERN’s Neutrino Platform. The wooded plot of land was transformed as crews extended a nearby facility and carved out a giant pit where ProtoDUNE-SP and its sister detector would live. CERN’s experts built a beamline that would funnel in the particle beam.

    Within the pit, welders got to work on a gigantic red steel frame, the external structure that would house the container with the detector components and the liquid argon needed to capture particle interactions. Researchers adapted algorithms and built up the software and hardware that would capture the electronic signals when a particle from the beam smashed into an argon nucleus in the detector. Things started coming together.

    Pieces of ProtoDUNE-SP began flowing in from around the world. Researchers from the Physical Sciences Lab at the University of Wisconsin-Madison sent the first of six crucial components called anode plane assemblies, special panels of wire that record particle interactions. On July 14, 2017, Cavanna sat in front of that very large APA shipping box at CERN and wondered how they would produce, test, and install five more before their stringent deadline just a bit more than a year ahead. The teams went into high gear. Detector parts came faster and faster.

    4
    An anode plane assembly (APA) is prepared for installation into ProtoDUNE.
    Photo by CERN

    “There were rumors that we would never make the schedule and we’d be lucky to put in two APAs,” Rameika says. “We were driven to prove we could deliver all of them, and we did.”

    Shipments of APAs from Wisconsin and a group of universities supported by the UK Science and Technology Facilities Council arrived. Teams tested detector components, then slid them through a narrow opening in the steel structure to an inner space where only a few people could work at a time. Fragile photo-sensors were added into the APAs. Electronics came together, cables were strung, and soon the temporary entrance in the side of the container was welded shut.

    To complete the final installation, technicians slid into the detector through a one-meter diameter manhole in the roof. CERN’s cryogenic experts filled the detector with 800 metric tons of liquid argon and turned on the purifiers, letting the detector cycle the clear liquid and remove any stray bits of non-argon material. The components within were cut off from any rescue should something go wrong. When the filling was completed almost eight weeks later, ProtoDUNE scientists checked the equipment. CERN’s particle accelerator operators sent streams of protons toward the detector, and researchers turned up the power on the high-voltage system.

    “The run started with this critical step that was keeping me up every night for three years,” Cavanna says. “It was the moment of bringing the detector to life, and I didn’t know what to expect.”

    Current flowed through the high-voltage system at a whopping 180,000 volts – exactly what it was supposed to do, “like it would be written in a textbook,” Cavanna says. Particle tracks showed up on the display, and soon after, celebratory champagne flowed in the ProtoDUNE control room at CERN. People around the world toasted their victory over video connections.

    Non-stop data

    When you have limited beam time, every second counts. Particles from the accelerator bombarded the ProtoDUNE detector 24 hours a day, seven days a week, but the deadline for shutting down the beam to prepare for a 2-year-long upgrade to the CERN accelerator complex loomed large.

    “You basically set aside your life when there’s beam,” Acciarri says. “You are always thinking and making sure everything is working properly. It’s very stressful.”

    After beam and detector tuning, between October 2 and November 12, ProtoDUNE-SP researchers collected more than 4 million gorgeous images of particle interactions. Members from participating institutions took shifts in the control rooms to make sure systems were operating as they should and watched the data roll in.

    “This is the first time we have had a live, 3-D event display for a liquid-argon detector,” says Tingjun Yang, co-convener for the data reconstruction and analysis group. Starting with the software used for the data analysis of another neutrino experiment, MicroBooNE, multiple groups collaborated to create a package to convert live data into the right format for quick, 3-D images that researchers on shift could use to monitor the detector.

    “We recognized this was a really powerful tool that DUNE will want to use,” Yang says. “We developed it, and the data worked. It was very beautiful.”


    This 3-D display shows a particle event at ProtoDUNE. The video shows the full size of the ProtoDUNE-SP detector (white box) and the direction of the particle beam (yellow arrow). Particles from other sources (such as cosmic rays) can be seen throughout the white box, while the red box highlights the region of interest: in this case, an interaction resulting from the particle beam passing through the detector. Event information, such as the momentum of particles in the beam and time of interaction, are located in the lower left corner. A selection of 3-D events from ProtoDUNE-SP are available in an online gallery for curious minds that want to play with the interface.

    Over the course of the run, researchers collected data about all sorts of different particles that might come out of a neutrino interaction in a detector: pions, kaons, photons, electrons, protons, and more. Because ProtoDUNE-SP sits on Earth’s surface, it also sees a high number of cosmic rays that the final DUNE detector won’t see from its mile-deep home at the Sanford Underground Research Facility in South Dakota.

    “It makes ProtoDUNE a great stress test for the detector and reconstruction capability,” Yang says. If the software tested at ProtoDUNE can handle the high number of particle interactions, it will be almost overqualified for the more serene environment of DUNE. Fermilab’s accelerator complex will send trillions of neutrinos through 800 miles of earth, but the far detectors will see only a handful every day. However, ProtoDUNE-SP’s robust data handling capabilities are needed to search for rare subatomic phenomena, such as the hypothesized decay of protons. It also ensures that DUNE can handle thousands of neutrino interactions in a few seconds if, say, a star explodes in the Milky Way.

    ProtoDUNE-SP also collected particles at the full range of energies DUNE expects to see: from 1 to 7 gigaelectronvolts (GeV). In fact, data-taking went so smoothly at these planned energies that researchers even had extra time to capture lower-energy particles, from 0.3 GeV up to 1 GeV. With precise control over the beam, scientists were able to carefully study how particles interact with the argon atoms – important physics studies in their own right – and test the detector components within.

    “The technology is here, and it’s ready for DUNE,” Acciarri says. “We’ll take this opportunity to change a few things, both on the hardware and software side, to make things go even smoother, but I do believe we reached more than what we were expecting or asking for this detector to show.”

    Looking ahead

    There is plenty still to do, Acciarri notes. DUNE will run for decades, so researchers aim to operate the prototype for as long as possible to monitor how the pieces of the detector fare over time. There also are plans for a series of tests on all the subsystems: things like the light detection system, electronics, and high-voltage system. They plan to test their models of fluid dynamics, seeing how the argon circulates in the detector, and how each subsystem affects the others. Two consortia are already working on improvements for the crucial anode plane assemblies for DUNE. On the software side, researchers will work to improve the stability of the system and the speed at which it captures events. And scientists are working to complete a second ProtoDUNE detector at CERN, known as the dual-phase ProtoDUNE.

    DUNE already has around 1,000 members from more than 30 countries and continues to grow. With all the ongoing planning, construction, and testing taking place around the world, the team of DUNE scientists and engineers, it seems, will have a busy and collaborative 2019.

    “That was something that was quite important beyond the technological success,” Cavanna says. “Technology without the right people is just a piece of material that is dead. We grew a community that will bring DUNE to life.”

    5
    An APA hangs from a crane in CERN’s Neutrino Platform
    Photo by CERN

    See the full article here .


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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 1:01 pm on December 25, 2018 Permalink | Reply
    Tags: "United States and France express interest to collaborate on construction of superconducting particle accelerator at Fermilab and the Deep Underground Neutrino Experiment, , , FNAL LBNF/ DUNE, , , ,   

    From Fermi National Accelerator Lab: “United States and France express interest to collaborate on construction of superconducting particle accelerator at Fermilab and the Deep Underground Neutrino Experiment” 

    FNAL II photo

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    From Fermi National Accelerator Lab , an enduring source of strength for the US contribution to scientific research world wide.

    December 19, 2018

    The U.S. Department of Energy (DOE), the French Atomic Energy Commission (CEA) and the French National Center for Scientific Research (CNRS) have signed statements this month expressing interest to collaborate on high-tech international particle physics projects that are planned to be hosted at DOE’s Fermi National Accelerator Laboratory.

    The three agencies indicated plans to work together on the development and production of technical components for PIP-II (Proton Improvement Plan-II), a major DOE particle accelerator project with substantial international contributions. In addition, CNRS and CEA also plan to collaborate on the construction of the Fermilab-hosted Deep Underground Neutrino Experiment (DUNE), an international flagship science project that will unlock the mysteries of neutrinos — subatomic particles that travel close to the speed of light and have almost no mass.

    1
    DOE Undersecretary for Science Paul Dabbar (left) and Vincent Berger, Director of Fundamental Research at the CEA, at the signing ceremony in France on Dec. 11. The signing with CNRS took place on Dec. 19.

    The construction of a 176-meter-long superconducting particle accelerator is the centerpiece of the PIP-II project. The new accelerator upgrade will become the heart of the Fermilab accelerator complex and provide the proton beam to power a broad program of accelerator-based particle physics research for many decades to come. In particular, PIP-II will enable the world’s most powerful high-energy neutrino beam to power DUNE. The experiment requires enormous quantities of neutrinos to discover the role these particles played in the formation of the early universe. The first delivery of particle beams to DUNE is scheduled for 2026.

    “The collaboration on PIP-II and DUNE is a win-win situation for France and the U.S. Department of Energy,” said DOE Undersecretary for Science Paul Dabbar. “Scientists in France and the United States have a wealth of experience building components for superconducting particle accelerators and are contributing substantially to developing key technologies for DUNE. France’s expression of interest brings into the fold for the projects a partnership that has already seen great interest and contributions from across the globe.”

    Two French institutions — the departments of the Institute of Research into the Fundamental Laws of the Universe (Irfu), part of the French Atomic Energy Commission, and the CNRS IN2P3 laboratories: Institute of Nuclear Physics (IPN) and Linear Accelerator Laboratory (LAL) — are expected to build components for PIP-II. They both have extensive experience in the development of superconducting radio-frequency acceleration, which is the enabling technology for PIP-II, and are contributors to two major superconducting particle accelerator projects in Europe: the X-ray Free Electron Laser (XFEL) and the (ESS).


    European XFEL campus

    ESS European Spallation Source, currently under construction in Lund, Sweden.

    “For IN2P3, the DUNE experiment is of major scientific interest for the next decade, and this interest naturally extends to the PIP-II project, which actually aligns perfectly well with our experience on superconducting linac technologies,” said IN2P3 Director Reynald Pain. “Our scientific and technical teams are very excited to start this collaboration.”

    At the heart of the PIP-II project is the construction of an 800-million-electronvolt superconducting linear accelerator. The new accelerator will feature acceleration cavities made of niobium and double the beam energy of its predecessor. That boost will enable the Fermilab accelerator complex to achieve megawatt-scale proton beam power.

    “Irfu physicists are strongly involved in neutrino physics,” said Vincent Berger, Director of Fundamental Research at the CEA. “In this field, the DUNE experiment is particularly promising. In that context, contributing to the PIP-II project would be very interesting for our accelerator teams, who have strong experience in superconducting linacs. Our first discussions with Fermilab staff have been very stimulating.”

    In addition to France, other international partners are making significant contributions to PIP-II: India, the United Kingdom and Italy. DOE’s Argonne and Lawrence Berkeley National laboratories are also contributing key components to the project.

    France brings world-leading expertise and capabilities to the PIP-II project,” said PIP-II Project Director Lia Merminga. “It is a tremendous opportunity and honor to work with them and apply their demonstrated excellence to our project.”

    French scientists also plan to contribute to building the DUNE detector, a massive stadium-sized neutrino detector that will be located 1.5 kilometers underground at Sanford Underground Research Facility in South Dakota. Construction of prototype detectors are currently under way at the European Organization for Nuclear Research (CERN), the European particle physics laboratory located near the French-Swiss border. These prototypes include key contributions from French institutions in developing the dual-phase technology for one of the two ProtoDUNE detectors.

    “French scientists were among the founders of the DUNE experiment,” said Ed Blucher, DUNE collaboration co-spokesperson and professor at the University of Chicago. “Their enormous experience in detector and electronics development will be crucial to successful construction of the DUNE detectors.”

    See the full article here .


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    FNAL Icon

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.


    FNAL/MINERvA

    FNAL DAMIC

    FNAL Muon g-2 studio

    FNAL Short-Baseline Near Detector under construction

    FNAL Mu2e solenoid

    Dark Energy Camera [DECam], built at FNAL

    FNAL DUNE Argon tank at SURF

    FNAL/MicrobooNE

    FNAL Don Lincoln

    FNAL/MINOS

    FNAL Cryomodule Testing Facility

    FNAL Minos Far Detector

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    FNAL/NOvA experiment map

    FNAL NOvA Near Detector

    FNAL ICARUS

    FNAL Holometer

     
  • richardmitnick 3:23 pm on November 20, 2018 Permalink | Reply
    Tags: , , , , FNAL LBNF/ DUNE, ,   

    From Fermi National Accelerator Lab: “How to build a towering millikelvin thermometer” 

    FNAL II photo

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    From Fermi National Accelerator Lab , an enduring source of strength for the US contribution to scientific research world wide.

    November 15, 2018
    Jim Daley

    Cary Kendziora had expected the long, slender temperature profile monitor to droop a bit, but not as much as this. As part of a joint project with the University of Hawaii at Manoa, Kendziora, a mechanical engineer at the U.S. Department of Energy’s Fermilab, had designed the device to measure the variation in temperature inside a massive neutrino detector located at the European laboratory CERN. The detector, the size of a small house, is filled with liquid argon. The temperature profile monitor is a solid piece of metal about 8 meters tall — about two stories tall — and as thin as a curtain rod. It bowed considerably when it was horizontal.

    Kendziora said he’d never worked with such a long, solid piece of metal that was also so narrow.

    “It turned out to be a lot more flexible than I imagined because of its length,” Kendziora said. “That was a surprise.”

    As a workaround, he helped build an exoskeleton support to keep the device rigid while it was being installed.

    The detector, one of two known as the ProtoDUNE detectors, contains 770 tons of liquid argon maintained at temperatures around 90 Kelvin.

    CERN Proto Dune

    Cern ProtoDune

    That’s a chilling minus 300 degrees Fahrenheit. As particles pass through the detector, they occasionally smash into the nuclei of argon atoms. The particles emerging from these collisions release electrons from argon atoms as they pass by. These electrons drift toward sensors that record their tracks. The tracks, in turn, give scientists information about the particle that started the reaction.

    2
    The temperature profiler from one of the ProtoDUNE detectors stands 8 meters tall. Photo: Cary Kendziora

    The ProtoDUNE detectors are prototypes for the international, Fermilab-hosted Deep Underground Neutrino Experiment. The DUNE detector, expected to be complete in the mid-2020s, will be mammoth, comprising four modules that are each nearly as long as a football field.

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    SURF DUNE LBNF Caverns at Sanford Lab

    FNAL DUNE Argon tank at SURF

    In liquid-argon detectors like DUNE and the ProtoDUNE detector, monitoring the variation in internal temperature is important because it’s correlated to the argon’s purity. ProtoDUNE contains 770 tons of liquid argon. DUNE will hold 70,000 tons. At this scale, the purification efficiency has to be checked regularly. If the argon doesn’t mix properly, it begins to stratify into layers of different temperatures, which can affect how far electrons can drift.

    “If the argon is pure, the electrons can drift the distance to the ProtoDUNE sensors, no problem,” said Jelena Maricic, an associate professor of physics at the University of Hawaii at Manoa who leads the group that worked on the design, construction and installation of the ProtoDUNE dynamic temperature profile monitor, along with Kendziora.

    But impurities have a great affinity for electrons and can trap them on their way to the sensors. And if they’re trapped, they won’t be detected, or at least not as easily.

    The temperature profile monitor hangs vertically from the detector’s ceiling near one corner of the detector, taking readings of the circulating liquid argon. By monitoring the argon’s temperature, scientists will be able to tell right away whether any problems are developing in the detector.

    Calibration by cross-reference

    Designing and building a temperature profile monitor that is accurate to within tens of millikelvin inside a massive liquid-argon detector is no small feat. While the degree of bowing was an unexpected problem, it was hardly the most difficult challenge to overcome. Kendziora ticked off a laundry list of them.

    “It had to be electrically and thermally isolated, and leak-tight,” he said. “And it’s a high-purity application, so all the materials had to be selected based on their not contributing any contaminants to the liquid. All the little threaded holes that the components are screwed into had to be vented so they wouldn’t trap any gas that would give off oxygen over a long period of time. All the parts had to be cleaned.”

    The entire design of the profile monitor also needed to address a unique question: How do you calibrate a probe that is sealed inside a giant box full of liquid argon? Erik Voirin, an engineer at Fermilab, and Yujing Sun, a postdoc in Maricic’s lab, independently hit upon the same, elegant idea.

    The team designed the profile monitor with an array of 23 motor-driven, remotely moveable sensors along its 8-meter height. Each takes a reading of the argon immediately surrounding it. And since they’re moveable, not only can a sensor take the temperature in multiple locations, but a single location’s temperature can be read out by more than one sensor.

    4
    The profile monitor is outfitted with an array of 23 motor-driven, remotely moveable sensors along its 8-meter height. Each takes a reading of the argon immediately surrounding it. Photo: Cary Kendziora

    Voirin, a thermal-fluids engineer, performed the computational fluid dynamics simulations for ProtoDUNE. Sun tested and demonstrated the idea to work with the prototype using just four sensors in 2017, deploying the rod in the 35-ton liquid-argon detector.

    “Our system allows you to move the sensors along the vertical axis and perform cross-calibration,” Maricic said.

    One could use sensor A to take the temperature at, say, the 3-meter mark, and then check its reading against sensor B’s at the same location. That way, scientists can determine if any sensor is out of whack.

    Maricic said that the University of Hawaii group team, will be performing the cross-calibration in the late November or early December.

    The DUNE far detector will require a similar temperature profile monitor that adheres to the same set of strict requirements that the ProtoDUNE detector needed – but with one difference. DUNE is much larger than ProtoDUNE, so its profile monitor needs to be scaled up accordingly. It will be 15 meters long — nearly double the length of the prototype profile monitor.

    “I don’t have a solution for the long length,” Kendziora says, other than to construct another extensive support infrastructure.

    Another engineering effort for DUNE— and he’s on top of it.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    FNAL Icon

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.


    FNAL/MINERvA

    FNAL DAMIC

    FNAL Muon g-2 studio

    FNAL Short-Baseline Near Detector under construction

    FNAL Mu2e solenoid

    Dark Energy Camera [DECam], built at FNAL

    FNAL DUNE Argon tank at SURF

    FNAL/MicrobooNE

    FNAL Don Lincoln

    FNAL/MINOS

    FNAL Cryomodule Testing Facility

    FNAL Minos Far Detector

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    FNAL/NOvA experiment map

    FNAL NOvA Near Detector

    FNAL ICARUS

    FNAL Holometer

     
  • richardmitnick 10:24 am on October 11, 2018 Permalink | Reply
    Tags: , , , , , , , , FNAL LBNF/ DUNE, , ,   

    From Don Lincoln via CNN: “The ultimate mystery of the universe” 

    1
    From CNN

    September 21, 2018

    FNAL’s Don Lincoln

    This might win an award for “most obvious statement ever,” but the universe is big. And with its size comes big questions. Perhaps the biggest is “What makes the universe, well…the universe?”
    Researchers have made a crucial step forward in their effort to build scientific equipment that will help us answer that fundamental question.

    An international group of physicists collaborating on the Deep Underground Neutrino Experiment (DUNE) have announced that a prototype version of their equipment, called ProtoDUNE, is now operational.
    ProtoDUNE will validate the technology of the much larger DUNE experiment, which is designed to detect neutrinos, subatomic particles most often created in violent nuclear reactions like those that occur in nuclear power plants or the Sun. While they are prodigiously produced, they can pass, ghost-like, through ordinary matter. There are three distinct types of neutrinos, as different as the strawberry, vanilla, and chocolate flavors of Neapolitan ice cream.

    Further, through the always-confusing rules of quantum mechanics, these three types of neutrinos experience a startling behavior — they literally change their identity. Following the ice cream analogy, this would be like starting to eat a scoop of vanilla and, a few spoonfuls in, it magically changes to chocolate. It is through this morphing behavior that scientists hope to explain why our universe looks the way it does, rather than like a featureless void, full of energy and nothing else.

    2
    View of the interior of the ProtoDUNE experiment

    CERN Proto DUNE Maximillian Brice

    Large enough to encompass a three-story house, ProtoDUNE is located at the CERN laboratory, just outside Geneva, Switzerland. Years in the making, ProtoDUNE is filled with 800 tons of chilled liquid argon, which detects the passage of subatomic particles like neutrinos. Neutrinos hit the nuclei of the argon atoms in the ProtoDUNE detector, causing particles with electrical charge to be produced. Those particles then move through the detector, banging into argon atoms and knocking their electrons off. Scientists then detect the electrons.
    It’s similar to how you can know an airplane recently passed overhead because you observe contrails, the white streaks in the sky it briefly leaves behind. The ProtoDUNE detector has now observed particles coming from space — what scientists call cosmic rays — which has validated the effectiveness of the particle detector.

    Though considerably large, ProtoDUNE pales in comparison to the size of the DUNE apparatus, which is still being developed. DUNE will be based at two locations: Fermi National Accelerator Laboratory (Fermilab), which is America’s flagship particle physics laboratory located just outside Chicago, and the Sanford Underground Research Facility (SURF), located in Lead, South Dakota.

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    Surf-Dune/LBNF Caverns at Sanford

    The biggest part of the DUNE experiment will ultimately consist of four large modules, each of which will be twenty times larger than ProtoDUNE. Because neutrinos interact very rarely with ordinary matter, bigger is better. And with an eighty times increase in volume, the DUNE detector will be able to detect eighty times as many neutrinos as ProtoDUNE.
    These large modules will be located nearly a mile underground at SURF. That depth is required to protect them from the same cosmic rays seen by ProtoDUNE.
    Fermilab will use its highest energy particle accelerator to generate a beam of neutrinos, which it will then shoot through the Earth to the waiting detectors over 800 miles away in western South Dakota.

    This beam of neutrinos will pass through a ProtoDUNE-like detector located at Fermilab to establish their characteristics as they leave the site. When the neutrinos arrive in South Dakota, the much bigger detectors again measure the neutrinos and look to see how much they have changed their identity as they traveled. It’s this identity-changing behavior that DUNE is designed to study. Scientists call this phenomenon “neutrino oscillations” because the neutrinos change from one type to another and then back again, over and over.
    While investigating and characterizing neutrino oscillations is the direct goal of the DUNE experiment, the deeper goal is to use those studies to shed light on one of those fundamental questions of the universe. This will be made possible because the DUNE experiment not only will study the oscillation behavior of neutrinos, it can also study the oscillation of antimatter neutrinos.

    A strong runner-up in the “most obvious statement ever” award is “our universe is made of matter.” But researchers have long known of a cousin substance called “antimatter.”

    Antimatter is the opposite of ordinary matter and will annihilate into pure energy when combined with matter. Alternatively, energy can simultaneously convert into matter and antimatter in equal quantities. This has been established beyond any credible doubt.

    Yet, with that observation, comes a mystery. Scientists generally accept that the universe came into existence through an event called the Big Bang. According to this theory, the universe was once much smaller, hotter, and full of energy. As the universe expanded, that energy should have converted into matter and antimatter in exactly equal quantities, which leads us to a very vexing question.

    Where the heck is the antimatter?

    Our universe consists only of matter, which means that something made the antimatter of the early universe disappear. Had this not happened, the matter and antimatter would have annihilated, and the universe would consist of nothing more than a bath of energy, without matter — without us.

    Which brings us back to the DUNE experiment. Fermilab will make not only neutrino beams, it will also make antimatter neutrino beams. The exact mix of neutrino “flavors” leaving the Fermilab campus will be established by the closer detector, and then again when they arrive at SURF, so that the changes due to neutrino oscillation can be measured. Then the same process will be done with antimatter neutrinos. If the matter and antimatter neutrinos oscillate differently, that will likely be a huge clue toward answering the question of why the universe exists as it does.

    With the completion of the new ProtoDUNE technology that will be used in the DUNE detector, the race is on to build the full facility. The first of the detector modules is scheduled to begin operations in 2026.

    While Fermilab has long made substantial contributions to the CERN research program, the DUNE experiment marks the first time that CERN has invested in scientific infrastructure in the United States. DUNE is a product of a unified international effort.
    Modern science is truly staggering in its accomplishments. We can cure deadly diseases and we’ve put men on the moon. But perhaps the grandest accomplishment of all is our ability to innovate in our effort to study in detail some of the oldest and most mind-boggling questions of our universe. And, with the success of ProtoDUNE, we’re that much closer to finding the answers.

    See the full article here .

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  • richardmitnick 2:04 pm on September 12, 2018 Permalink | Reply
    Tags: , FNAL LBNF/ DUNE, , , , ,   

    From Fermi National Accelerator Lab: “MicroBooNE demonstrates use of convolutional neural networks on liquid-argon TPC data for first time” 

    FNAL II photo

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    Fermi National Accelerator Lab is an enduring source of strength for the US contribution to scientific research world wide.

    September 12, 2018
    Victor Genty, Kazuhiro Terao and Taritree

    It is hard these days not to encounter examples of machine learning out in the world. Chances are, if your phone unlocks using facial recognition or if you’re using voice commands to control your phone, you are likely using machine learning algorithms — in particular deep neural networks.

    What makes these algorithms so powerful is that they learn relationships between high-level concepts we wish to find in an image (faces) or sound wave (words) with sets of low-level patterns (lines, shapes, colors, textures, individual sounds), which represent them in the data. Furthermore, these low-level patterns and relationships do not have to be conceived of or hand-designed by humans, but instead are learned directly from examples of the data. Not having to come up with new patterns to find for each new problem is why deep neural networks have been able to advance the state of the art for so many different types of problems: from analyzing video for self-driving cars to assisting robots in learning how to manipulate objects.

    Here at Fermilab, there has been a lot of effort in having these deep neural networks help us analyze the data from our particle detectors so that we can more quickly and effectively use it to look for new physics. These applications are a continuation of the high-energy physics community’s long history in adopting and furthering the use of machine learning algorithms.

    Recently, the MicroBooNE neutrino experiment published a paper describing how they used convolutional neural networks — a particular type of deep neural network — to sort individual pixels coming from images made by a particular type of detector known as a liquid-argon time projection (LArTPC) chamber. The experiment designed a convolutional neural network called U-ResNet to distinguish between two types of pixels: those that were a part of a track-like particle trajectory from those that were a part of a shower-like particle trajectory.

    1
    This plot shows a comparison of U-ResNet performance on data and simulation, where the true pixel labels are provided by a physicist. The sample used is 100 events that contain a charged-current neutrino interaction candidate with neutral pions produced at the event vertex. The horizontal axis shows the fraction of pixels where the prediction by U-ResNet differed from the labels for each event. The error bars indicate only a statistical uncertainty.

    Track-like trajectories, made by particles such as a muon or proton, consist of a line with small curvature. Shower-like trajectories, produced by particles such as an electron or photon, are more complex topological features with many branching trajectories. This distinction is important because separating these type of topologies is known to be difficult for traditional algorithms. Not only that, shower-like shapes are produced when electrons and photons interact in the detector, and these two particles are often an important signal or background in physics analyses.

    MicroBooNE researchers demonstrated that these networks not only performed well but also worked in a similar fashion when presented with simulated data and real data. The latter is the first time this has been demonstrated for data from LArTPCs.

    Showing that networks behave the same on simulated and real data is critical, because these networks are typically trained on simulated data. Recall that these networks learn by looking at many examples. In industry, gathering large “training” data sets is an arduous and expensive task. However, particle physicists have a secret weapon — they can create as much simulated data as they want, since all experiments produce a highly detailed model of their detectors and data acquisition systems in order to produce as faithful a representation of the data as possible.

    However, these models are never perfect. And so a big question was, “Is the simulated data close enough to the real data to properly train these neural networks?” The way MicroBooNE answered this question is by performing a Turing test that compares the performance of the network to that of a physicist. They demonstrated that the accuracy of the human was similar to the machine when labeling simulated data, for which an absolute accuracy can be defined. They then compared the labels for real data. Here the disagreement between labels was low, and similar between machine and human (See the top figure. See the figure below for an example of how a human and computer labeled the same data event.) In addition, a number of qualitative studies looked at the correlation between manipulations of the image and the label provided by the network. They showed that the correlations follow human-like intuitions. For example, as a line segment gets shorter, the network becomes less confident if the segment is due to a track or a shower. This suggests that the low-level correlations being used are the same physically motivated correlations a physicist would use if engineering an algorithm by hand.

    2
    This example image shows a charged-current neutrino interaction with decay gamma rays from a neutral pion (left). The label image (middle) is shown with the output of U-ResNet (right) where track and shower pixels are shown in yellow and cyan color respectively.

    Demonstrating this simulated-versus-real data milestone is important because convolutional neural networks are valuable to current and future neutrino experiments that will use LArTPCs. This track-shower labeling is currently being employed in upcoming MicroBooNE analyses. Furthermore, for the upcoming Deep Underground Neutrino Experiment (DUNE), convolutional neural networks are showing much promise toward having the performance necessary to achieve DUNE’s physics goals, such as the measurement of CP violation, a possible explanation of the asymmetry in the presence of matter and antimatter in the current universe.

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA


    FNAL DUNE Argon tank at SURF


    Surf-Dune/LBNF Caverns at Sanford



    SURF building in Lead SD USA

    The more demonstrations there are that these algorithms work on real LArTPC data, the more confidence the community can have that convolutional neural networks will help us learn about the properties of the neutrino and the fundamental laws of nature once DUNE begins to take data.

    Science paper:
    A Deep Neural Network for Pixel-Level Electromagnetic Particle Identification in the MicroBooNE Liquid Argon Time Projection Chamber
    https://arxiv.org/abs/1808.07269

    Victor Genty, Kazuhiro Terao and Taritree Wongjirad are three of the scientists who analyzed this result. Victor Genty is a graduate student at Columbia University. Kazuhiro Terao is a physicist at SLAC National Accelerator Laboratory. Taritree Wongjirad is an assistant professor at Tufts University.

    See the full article here .

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    Please help promote STEM in your local schools.

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    FNAL Icon

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.


    FNAL/MINERvA

    FNAL DAMIC

    FNAL Muon g-2 studio

    FNAL Short-Baseline Near Detector under construction

    FNAL Mu2e solenoid

    Dark Energy Camera [DECam], built at FNAL

    FNAL DUNE Argon tank at SURF

    FNAL/MicrobooNE

    FNAL Don Lincoln

    FNAL/MINOS

    FNAL Cryomodule Testing Facility

    FNAL Minos Far Detector

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

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  • richardmitnick 2:52 pm on August 7, 2018 Permalink | Reply
    Tags: , , FNAL LBNF/ DUNE, , ,   

    From Symmetry: “A dual-phase DUNE” 

    Symmetry Mag
    From Symmetry

    08/07/18
    Lauren Biron

    The Deep Underground Neutrino Experiment is advancing technology commonly used in dark matter experiments—and scaling it up to record-breaking sizes.

    1
    Photo by CERN

    It’s an exciting time in particle physics. Puzzles abound. There are hints of things that don’t fit with scientists’ best model of the universe—and researchers are taking inspiration from one another as they investigate them all.

    One recent example comes from the Deep Underground Neutrino Experiment, an international megascience project with more than 1100 scientists from 32 countries. It’s hosted by the Department of Energy’s Fermi National Accelerator Laboratory in Batavia, Illinois. Fermilab will send a beam of particles called neutrinos straight through 800 miles (1300 km) of earth to a huge particle detector—four modules holding 70,000 total tons of liquid argon—to be housed at the Sanford Underground Research Facility in South Dakota. Scientists hope to learn more about the properties of these mysterious particles, which might have something to do with why matter exists.

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA


    FNAL DUNE Argon tank at SURF


    Surf-Dune/LBNF Caverns at Sanford



    SURF building in Lead SD USA

    One of the prototypes for the huge DUNE detector modules will use a concept that’s relatively new for neutrino science but familiar to researchers from other parts of particle physics: the dual-phase detector.

    Learning from dark matter searches

    Matter comes in different phases, the most familiar of which are solid, liquid and gas. All dual-phase particle detectors to date have one thing in common: They use a combination of liquid and gas phases. This will also be true for DUNE, whose dual-phase module of liquid and gaseous argon will make it the largest dual-phase detector ever created when it comes online in the mid-2020s.

    Dual-phase detectors can record a particle interaction twice: first when the collision occurs in the liquid, creating a flash of light, and again when the resulting spray of particles enters the area filled with gas and produces even more signals. Having these two indicators allows for an especially precise and clear reconstruction of the original interaction.

    2
    Researcher Jae Yu checks components within the dual-phase ProtoDUNE detector. Photo by CERN.

    Neutrino experiments using dual-phase technology have started cropping up only in the past few years, but it’s been an industry standard for dark matter experiments for much longer.

    Neutrinos and dark matter are two of the biggest mysteries in particle physics today. Neutrinos rarely interact with matter, and it took about 25 years from the theoretical “invention” of neutrinos to their actual detection in 1956. Today, neutrinos intrigue scientists with their tiny yet unexpected masses and their ability to morph between at least three different types as they travel throughout the universe. Dark matter has never been directly observed, but scientists infer the existence of these proposed particles from indirect evidence such as the unlikely speed at which galaxies spin without coming apart.

    Dual-phase technology for dark matter detectors, originally proposed in the 1970s, is well established and has helped produce leading dark matter results for the past decade, says Cristian Galbiati, a physicist at Princeton and spokesperson for the DarkSide-50 dark matter experiment currently collecting data at INFN’s Gran Sasso National Laboratory in Italy.

    Dark Side-50 Dark Matter Experiment at Gran Sasso

    Gran Sasso LABORATORI NAZIONALI del GRAN SASSO, located in the Abruzzo region of central Italy

    Like DUNE, DarkSide uses argon as a detection medium. But each experiment faces its own particular challenges. For one, unlike DUNE, DarkSide must have no background noise—signals that could be misinterpreted as a dark matter particle discovery.

    “As soon as you have one event of background, you are toast,” Galbiati says. “Dual-phase detectors are proven to deliver a completely background-free condition if the argon is clean.”

    This means that the experiment has to use argon with very low radioactivity, specially procured and distilled from an underground source in Colorado. It will also be true for the next generation of the experiment, DarkSide-20k, which will require 20 tons of the ultrapure argon. Researchers working on multiple small-scale dark matter detectors that use argon, including DEAP 3600, ARDM, MiniCLEAN, and DarkSide-50, have joined together and formed the Global Dark Matter Argon Collaboration to work on that next-generation detector, scheduled to come online at Gran Sasso in 2022. It will be followed by an even larger version around 2027.

    DEAP Dark Matter detector, The DEAP-3600, suspended in the SNOLAB deep in Sudbury’s Creighton Mine

    ARDM experiment at the Laboratorio Subterráneo de Canfranc (LSC) in Spain

    MiniCLEAN detector


    MiniCLEAN Dark Matter experiment at SNOLAB, Canada

    Argon isn’t the only game in town. Other dual-phase dark matter detectors use different noble gases, such as the xenon in LUX or the next-generation LUX-ZEPLIN experiment. LZ will use 10 tons of the material and should see “first dark” in 2020.

    LBNL Lux Zeplin project at SURF

    LUX dark matter experiment Photomultiplier tubes, which collect light, were installed in this frame for the experiment

    Like DUNE’s dual-phase prototype, the LZ detector is a big, complicated instrument with lots of different systems that have to come together, says Dan McKinsey, co-spokesperson of LUX and a scientist at Lawrence Berkeley National Laboratory and UC Berkeley who is working on LZ. He lists off a few of the technological advances the project is working on that are also relevant to dual-phase neutrino detectors like DUNE: “High voltage, light collection, purity—these challenges all scale. They become bigger challenges as detectors grow.”

    Pushing technologies with a dual-phase DUNE

    DUNE will make use of both single-phase and dual-phase detector modules at the experiment’s far site in South Dakota.

    Single-phase argon technology, which uses only liquid argon, has already been demonstrated in short-distance neutrino experiments—like MicroBooNE at Fermilab, which uses a school-bus-sized detector—and in long-distance experiments—like ICARUS, a 760-ton detector that previously operated at Gran Sasso using a neutrino beam that traveled 450 miles (725 km) from CERN, the European Center for Nuclear Research. And dual-phase neutrino tech made significant progress with the WA105 3X1X1 detector.

    Proto Dune WA105 3X1X1 detector at CERN

    Nevertheless, when you’re building up to something as big as DUNE, you want to run tests to make sure everything works as expected. To that end, collaborators are building enormous single-phase and dual-phase testbeds called the ProtoDUNE detectors at CERN. At the laboratory’s new neutrino platform, led by Marzio Nessi, scientists are now completing the two 800-ton detectors to give the technologies for DUNE a final test.

    3
    The two ProtoDUNE detectors are housed at CERN’s neutrino platform. Photo by CERN

    “The goal of these devices is to develop the technology and be sure we do things the right way,” says Filippo Resnati, technical coordinator of the neutrino facility at CERN. “But it’s also very nice to know that despite these being tests, these are the two biggest liquid-argon time projection chambers that have ever been built, and by far in the shortest time.”

    The single-phase prototype should finish filling with liquid argon and be commissioned by the end of summer, seeing first particle tracks in the fall. The dual-phase prototype recently finished the first test of a key component called the charge readout plane, or CRP, which will amplify the electrons into the gas and collect their signals. The CRPs and other components should be installed this fall.

    “We have to make sure we are working together as a team and that each of these technologies can work,” says Jae Yu, a physicist at the University of Texas at Arlington who works on the dual-phase ProtoDUNE. “It’s always better to have different technologies so we can cross check each other.”

    Some of the advantages of using the dual-phase technology are, compared to the single-phase setup, stronger and cleaner signals and a lower energy threshold, meaning the detector can see lower-energy neutrinos. Amplifying the electrons in the gas makes the signal stand out from background noise. Single-phase detectors try to collect the signal as soon as possible, meaning the electronics are usually inside the detector, within the liquid argon at a cryogenic temperature. In contrast, the dual-phase detector’s electronics will be housed in special chimneys that are accessible from the outside.

    “You can access the electronics at any moment needed, without contaminating the liquid argon,” says Dario Autiero, DUNE project leader for the French National Institute of Nuclear and Particle Physics (IN2P3) groups. “This concept and the design of the electronics are innovative, and it took a long time to develop them.”

    Another bonus: almost all of the liquid argon inside the dual-phase detector is one large, signal-producing region, making the data analysis less complicated. In contrast, single-phase detectors are segmented into chunks, meaning the different sections later have to be combined together for data analysis, and gaps accounted for.

    But with those benefits come challenges for the dual-phase design of DUNE.

    The cathode of the field cage—the electrical component which draws the electrons towards the signal-recording pieces—must be operated at a mind-boggling voltage of around 600,000 volts. In addition, the CRPs must lie perfectly level at the border of the liquid and gas phases of argon and function stably, without sparking.

    “We are pioneers, in a sense,” says Inés Gil Botella, leader of the CIEMAT group in Spain that is working on the elements that will capture the light within the dual-phase detector. “This is a technology challenge at these scales because it has never been done before. It’s a very exciting time, but also a very critical time. We are advancing the technology.”

    The overlap between dual-phase technologies for dark matter and neutrino experiments will continue for the foreseeable future. The Global Argon Dark Matter Collaboration already is looking at the design of the ProtoDUNE cryostat as a potential casing for their 20-ton experiment, and ProtoDUNE collaborators are looking at how the dual-phase prototype detector could be used to look for a particular kind of dark matter.

    “The more I think about it, the more I fall in love with this technology,” Yu says. “It’s beautiful. It’s mesmerizing. It’s a piece of art. It’s elegant. And it’s just the beginning. There’s a lot more work to be done.”

    See the full article here .


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    Symmetry is a joint Fermilab/SLAC publication.


     
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