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  • richardmitnick 2:02 pm on September 21, 2017 Permalink | Reply
    Tags: A2D2, , , IARC-Fermilab’s Illinois Accelerator Research Center, , , , Symmetry Magazine   

    From Symmetry: “Concrete applications for accelerator science” 

    Symmetry Mag

    Symmetry

    09/21/17
    Leah Poffenberger

    1
    Photo by Reidar Hahn, Fermilab

    A project called A2D2 will explore new applications for compact linear accelerators.

    Particle accelerators are the engines of particle physics research at Fermi National Accelerator Laboratory. They generate nearly light-speed, subatomic particles that scientists study to get to the bottom of what makes our universe tick. Fermilab experiments rely on a number of different accelerators, including a powerful, 500-foot-long linear accelerator that kick-starts the process of sending particle beams to various destinations.

    But if you’re not doing physics research, what’s an accelerator good for?

    It turns out, quite a lot: Electron beams generated by linear accelerators have all kinds of practical uses, such as making the wires used in cars melt-resistant or purifying water.

    A project called Accelerator Application Development and Demonstration (A2D2) at Fermilab’s Illinois Accelerator Research Center will help Fermilab and its partners to explore new applications for compact linear accelerators, which are only a few feet long rather than a few hundred. These compact accelerators are of special interest because of their small size—they’re cheaper and more practical to build in an industrial setting than particle physics research accelerators—and they can be more powerful than ever.

    “A2D2 has two aspects: One is to investigate new applications of how electron beams might be used to change, modify or process different materials,” says Fermilab’s Tom Kroc, an A2D2 physicist. “The second is to contribute a little more to the understanding of how these processes happen.”

    To develop these aspects of accelerator applications, A2D2 will employ a compact linear accelerator that was once used in a hospital to treat tumors with electron beams. With a few upgrades to increase its power, the A2D2 accelerator will be ready to embark on a new venture: exploring and benchmarking other possible uses of electron beams, which will help specify the design of a new, industrial-grade, high-power machine under development by IARC and its partners.

    It won’t be just Fermilab scientists using the A2D2 accelerator: As part of IARC, the accelerator will be available for use (typically through a formal CRADA or SPP agreement) by anyone who has a novel idea for electron beam applications. IARC’s purpose is to partner with industry to explore ways to translate basic research and tools, including accelerator research, into commercial applications.

    “I already have a lot of people from industry asking me, ‘When can I use A2D2?’” says Charlie Cooper, general manager of IARC. “A2D2 will allow us to directly contribute to industrial applications—it’s something concrete that IARC now offers.”

    Speaking of concrete, one of the first applications in mind for compact linear accelerators is creating durable pavement for roads that won’t crack in the cold or spread out in the heat. This could be achieved by replacing traditional asphalt with a material that could be strengthened using an accelerator. The extra strength would come from crosslinking, a process that creates bonds between layers of material, almost like applying glue between sheets of paper. A single sheet of paper tears easily, but when two or more layers are linked by glue, the paper becomes stronger.

    “Using accelerators, you could have pavement that lasts longer, is tougher and has a bigger temperature range,” says Bob Kephart, director of IARC. Kephart holds two patents for the process of curing cement through crosslinking. “Basically, you’d put the road down like you do right now, and you’d pass an accelerator over it, and suddenly you’d turn it into really tough stuff—like the bed liner in the back of your pickup truck.”

    This process has already caught the eye of the U.S. Army Corps of Engineers, which will be one of A2D2’s first partners. Another partner will be the Chicago Metropolitan Water Reclamation District, which will test the utility of compact accelerators for water purification. Many other potential customers are lining up to use the A2D2 technology platform.

    “You can basically drive chemical reactions with electron beams—and in many cases those can be more efficient than conventional technology, so there are a variety of applications,” Kephart says. “Usually what you have to do is make a batch of something and heat it up in order for a reaction to occur. An electron beam can make a reaction happen by breaking a bond with a single electron.”

    In other words, instead of having to cook a material for a long time to reach a specific heat that would induce a chemical reaction, you could zap it with an electron beam to get the same effect in a fraction of the time.

    In addition to exploring the new electron-beam applications with the A2D2 accelerator, scientists and engineers at IARC are using cutting-edge accelerator technology to design and build a new kind of portable, compact accelerator, one that will take applications uncovered with A2D2 out of the lab and into the field. The A2D2 accelerator is already small compared to most accelerators, but the latest R&D allows IARC experts to shrink the size while increasing the power of their proposed accelerator even further.

    “The new, compact accelerator that we’re developing will be high-power and high-energy for industry,” Cooper says. “This will enable some things that weren’t possible in the past. For something such as environmental cleanup, you could take the accelerator directly to the site.”

    While the IARC team develops this portable accelerator, which should be able to fit on a standard trailer, the A2D2 accelerator will continue to be a place to experiment with how to use electron beams—and study what happens when you do.

    “The point of this facility is more development than research, however there will be some research on irradiated samples,” says Fermilab’s Mike Geelhoed, one of the A2D2 project leads. “We’re all excited—at least I am. We and our partners have been anticipating this machine for some time now. We all want to see how well it can perform.”

    See the full article here .

    Please help promote STEM in your local schools.

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    Symmetry is a joint Fermilab/SLAC publication.


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  • richardmitnick 4:03 pm on September 15, 2017 Permalink | Reply
    Tags: , , , , , Light dark matter, , SENSEI prototype, Symmetry Magazine   

    From Symmetry: “SENSEI searches for light dark matter” 

    Symmetry Mag

    Symmetry

    09/15/17
    Leah Poffenberger

    Technology proposed 30 years ago to search for dark matter is finally seeing the light.

    1
    FNAL SENSEI prototype. Photo by Reidar Hahn, Fermilab

    In a project called SENSEI, scientists are using innovative sensors developed over three decades to look for the lightest dark matter particles anyone has ever tried to detect.

    Dark matter—so named because it doesn’t absorb, reflect or emit light—constitutes 27 percent of the universe, but the jury is still out on what it’s made of. The primary theoretical suspect for the main component of dark matter is a particle scientists have descriptively named the weakly interactive massive particle, or WIMP.

    But since none of these heavy particles, which are expected to have a mass 100 times that of a proton, have shown up in experiments, it might be time for researchers to think small.

    “There is a growing interest in looking for different kinds of dark matter that are additives to the standard WIMP model,” says Fermi National Accelerator Laboratory scientist Javier Tiffenberg, a leader of the SENSEI collaboration. “Lightweight, or low-mass, dark matter is a very compelling possibility, and for the first time, the technology is there to explore these candidates.”

    Sensing the unseen

    In traditional dark matter experiments, scientists look for a transfer of energy that would occur if dark matter particles collided with an ordinary nucleus. But SENSEI is different; it looks for direct interactions of dark matter particles colliding with electrons.

    “That is a big difference—you get a lot more energy transferred in this case because an electron is so light compared to a nucleus,” Tiffenberg says.

    If dark matter had low mass—much smaller than the WIMP model suggests—then it would be many times lighter than an atomic nucleus. So if it were to collide with a nucleus, the resulting energy transfer would be far too small to tell us anything. It would be like throwing a ping-pong ball at a boulder: The heavy object wouldn’t go anywhere, and there would be no sign the two had come into contact.

    An electron is nowhere near as heavy as an atomic nucleus. In fact, a single proton has about 1836 times more mass than an electron. So the collision of a low-mass dark matter particle with an electron has a much better chance of leaving a mark—it’s more bowling ball than boulder.

    Bowling balls aren’t exactly light, though. An energy transfer between a low-mass dark matter particle and an electron would leave only a blip of energy, one either too small for most detectors to pick up or easily overshadowed by noise in the data.

    “The bowling ball will move a very tiny amount,” says Fermilab scientist Juan Estrada, a SENSEI collaborator. “You need a very precise detector to see this interaction of lightweight particles with something that is much heavier.”

    That’s where SENSEI’s sensitive sensors come in.

    SENSEI will use skipper charge-couple devices, also called skipper CCDs. CCDs have been used for other dark matter detection experiments, such as the Dark Matter in CCDs (or DAMIC) experiment operating at SNOLAB in Canada.

    3
    DAMIC experiment operating at SNOLAB

    These CCDs were a spinoff from sensors developed for use in the Dark Energy Camera in Chile and other dark energy search projects.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    CCDs are typically made of silicon divided into pixels. When a dark matter particle passes through the CCD, it collides with the silicon’s electrons, knocking them free, leaving a net electric charge in each pixel the particle passes through. The electrons then flow through adjacent pixels and are ultimately read as a current in a device that measures the number of electrons freed from each CCD pixel. That measurement tells scientists about the mass and energy of the particle that got the chain reaction going. A massive particle, like a WIMP, would free a gusher of electrons, but a low-mass particle might free only one or two.

    Typical CCDs can measure the charge left behind only once, which makes it difficult to decide if a tiny energy signal from one or two electrons is real or an error.

    Skipper CCDs are a new generation of the technology that helps eliminate the “iffiness” of a measurement that has a one- or two-electron margin of error. “The big step forward for the skipper CCD is that we are able to measure this charge as many times as we want,” Tiffenberg says.

    The charge left behind in the skipper CCD can be sampled multiple times and then averaged, a method that yields a more precise measurement of the charge deposited in each pixel than the measure-one-and-done technique. That’s the rule of statistics: With more data, you get closer to a property’s true value.

    SENSEI scientists take advantage of the skipper CCD architecture, measuring the number of electrons in a single pixel a whopping 4000 times.

    “This is a simple idea, but it took us 30 years to get it to work,” Estrada says.

    From idea to reality to beyond

    A small SENSEI prototype is currently running at Fermilab in a detector hall 385 feet below ground, and it has demonstrated that this detector design will work in the hunt for dark matter.

    FNAL DAMIC

    Skipper CCD technology and SENSEI were brought to life by Laboratory Directed Research and Development (LDRD) funds at Fermilab and Lawrence Berkeley National Laboratory (Berkeley Lab). LDRD programs are intended to provide funding for development of novel, cutting-edge ideas for scientific discovery.

    The Fermilab LDRDs were awarded only recently—less than two years ago—but close collaboration between the two laboratories has already yielded SENSEI’s promising design, partially thanks to Berkeley lab’s previous work in skipper CCD design.

    Fermilab LDRD funds allow researchers to test the sensors and develop detectors based on the science, and the Berkeley Lab LDRD funds support the sensor design, which was originally proposed by Berkeley Lab scientist Steve Holland.

    “It is the combination of the two LDRDs that really make SENSEI possible,” Estrada says.

    Future SENSEI research will also receive a boost thanks to a recent grant from the Heising-Simons Foundation.

    “SENSEI is very cool, but what’s really impressive is that the skipper CCD will allow the SENSEI science and a lot of other applications,” Estrada says. “Astronomical studies are limited by the sensitivity of their experimental measurements, and having sensors without noise is the equivalent of making your telescope bigger—more sensitive.”

    SENSEI technology may also be critical in the hunt for a fourth type of neutrino, called the sterile neutrino, which seems to be even more shy than its three notoriously elusive neutrino family members.

    A larger SENSEI detector equipped with more skipper CCDs will be deployed within the year. It’s possible it might not detect anything, sending researchers back to the drawing board in the hunt for dark matter. Or SENSEI might finally make contact with dark matter—and that would be SENSEI-tional.

    See the full article here .

    Please help promote STEM in your local schools.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 9:55 pm on September 5, 2017 Permalink | Reply
    Tags: , , , , , , , , , , , , , Symmetry Magazine   

    From Symmetry: “What can particles tell us about the cosmos?” 

    Symmetry Mag
    Symmetry

    09/05/17
    Amanda Solliday

    The minuscule and the immense can reveal quite a bit about each other.

    In particle physics, scientists study the properties of the smallest bits of matter and how they interact. Another branch of physics—astrophysics—creates and tests theories about what’s happening across our vast universe.

    1
    The current theoretical framework that describes elementary particles and their forces, known as the Standard Model, is based on experiments that started in 1897 with the discovery of the electron. Today, we know that there are six leptons, six quarks, four force carriers and a Higgs boson. Scientists all over the world predicted the existence of these particles and then carried out the experiments that led to their discoveries. Learn all about the who, what, where and when of the discoveries that led to a better understanding of the foundations of our universe.

    While particle physics and astrophysics appear to focus on opposite ends of a spectrum, scientists in the two fields actually depend on one another. Several current lines of inquiry link the very large to the very small.

    The seeds of cosmic structure

    For one, particle physicists and astrophysicists both ask questions about the growth of the early universe.

    In her office at Stanford University, Eva Silverstein explains her work parsing the mathematical details of the fastest period of that growth, called cosmic inflation.

    Lambda-Cold Dark Matter, Accelerated Expansion of the Universe, Big Bang-Inflation (timeline of the universe) Date 2010 Credit: Alex MittelmannColdcreation

    “To me, the subject is particularly interesting because you can understand the origin of structure in the universe,” says Silverstein, a professor of physics at Stanford and the Kavli Institute for Particle Astrophysics and Cosmology. “This paradigm known as inflation accounts for the origin of structure in the most simple and beautiful way a physicist can imagine.”

    Scientists think that after the Big Bang, the universe cooled, and particles began to combine into hydrogen atoms. This process released previously trapped photons—elementary particles of light.

    The glow from that light, called the cosmic microwave background, lingers in the sky today.

    CMB per ESA/Planck

    Scientists measure different characteristics of the cosmic microwave background to learn more about what happened in those first moments after the Big Bang.

    According to scientists’ models, a pattern that first formed on the subatomic level eventually became the underpinning of the structure of the entire universe. Places that were dense with subatomic particles—or even just virtual fluctuations of subatomic particles—attracted more and more matter. As the universe grew, these areas of density became the locations where galaxies and galaxy clusters formed. The very small grew up to be the very large.

    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    Scientists studying the cosmic microwave background hope to learn about more than just how the universe grew—it could also offer insight into dark matter, dark energy and the mass of the neutrino.

    Dark Matter

    Dark matter cosmic web and the large-scale structure it forms The Millenium Simulation, V. Springel et al

    Dark Matter Particle Explorer China

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

    LUX Dark matter Experiment at SURF, Lead, SD, USA

    ADMX Axion Dark Matter Experiment, U Uashington

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    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

    “It’s amazing that we can probe what was going on almost 14 billion years ago,” Silverstein says. “We can’t learn everything that was going on, but we can still learn an incredible amount about the contents and interactions.”

    For many scientists, “the urge to trace the history of the universe back to its beginnings is irresistible,” wrote theoretical physicist Stephen Weinberg in his 1977 book The First Three Minutes. The Nobel laureate added, “From the start of modern science in the sixteenth and seventeenth centuries, physicists and astronomers have returned again and again to the problem of the origin of the universe.”

    Searching in the dark

    Particle physicists and astrophysicists both think about dark matter and dark energy. Astrophysicists want to know what made up the early universe and what makes up our universe today. Particle physicists want to know whether there are undiscovered particles and forces out there for the finding.

    “Dark matter makes up most of the matter in the universe, yet no known particles in the Standard Model [of particle physics] have the properties that it should possess,” says Michael Peskin, a professor of theoretical physics at SLAC.

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    “Dark matter should be very weakly interacting, heavy or slow-moving, and stable over the lifetime of the universe.”

    There is strong evidence for dark matter through its gravitational effects on ordinary matter in galaxies and clusters. These observations indicate that the universe is made up of roughly 5 percent normal matter, 25 percent dark matter and 70 percent dark energy. But to date, scientists have not directly observed dark energy or dark matter.

    “This is really the biggest embarrassment for particle physics,” Peskin says. “However much atomic matter we see in the universe, there’s five times more dark matter, and we have no idea what it is.”

    But scientists have powerful tools to try to understand some of these unknowns. Over the past several years, the number of models of dark matter has been expanding, along with the number of ways to detect it, says Tom Rizzo, a senior scientist at SLAC and head of the theory group.

    Some experiments search for direct evidence of a dark matter particle colliding with a matter particle in a detector. Others look for indirect evidence of dark matter particles interfering in other processes or hiding in the cosmic microwave background. If dark matter has the right properties, scientists could potentially create it in a particle accelerator such as the Large Hadron Collider.

    LHC

    CERN/LHC Map

    CERN LHC Tunnel

    CERN LHC particles

    Physicists are also actively hunting for signs of dark energy. It is possible to measure the properties of dark energy by observing the motion of clusters of galaxies at the largest distances that we can see in the universe.

    “Every time that we learn a new technique to observe the universe, we typically get lots of surprises,” says Marcelle Soares-Santos, a Brandeis University professor and a researcher on the Dark Energy Survey. “And we can capitalize on these new ways of observing the universe to learn more about cosmology and other sides of physics.”

    Forces at play

    Particle physicists and astrophysicists find their interests also align in the study of gravity. For particle physicists, gravity is the one basic force of nature that the Standard Model does not quite explain. Astrophysicists want to understand the important role gravity played and continues to play in the formation of the universe.

    In the Standard Model, each force has what’s called a force-carrier particle or a boson. Electromagnetism has photons. The strong force has gluons. The weak force has W and Z bosons. When particles interact through a force, they exchange these force-carriers, transferring small amounts of information called quanta, which scientists describe through quantum mechanics.

    General relativity explains how the gravitational force works on large scales: Earth pulls on our own bodies, and planetary objects pull on each other. But it is not understood how gravity is transmitted by quantum particles.

    Discovering a subatomic force-carrier particle for gravity would help explain how gravity works on small scales and inform a quantum theory of gravity that would connect general relativity and quantum mechanics.

    Compared to the other fundamental forces, gravity interacts with matter very weakly, but the strength of the interaction quickly becomes larger with higher energies. Theorists predict that at high enough energies, such as those seen in the early universe, quantum gravity effects are as strong as the other forces. Gravity played an essential role in transferring the small-scale pattern of the cosmic microwave background into the large-scale pattern of our universe today.

    “Another way that these effects can become important for gravity is if there’s some process that lasts a long time,” Silverstein says. “Even if the energies aren’t as high as they would need to be sensitive to effects like quantum gravity instantaneously.”

    Physicists are modeling gravity over lengthy time scales in an effort to reveal these effects.

    Our understanding of gravity is also key in the search for dark matter. Some scientists think that dark matter does not actually exist; they say the evidence we’ve found so far is actually just a sign that we don’t fully understand the force of gravity.

    Big ideas, tiny details

    Learning more about gravity could tell us about the dark universe, which could also reveal new insight into how structure in the universe first formed.

    Scientists are trying to “close the loop” between particle physics and the early universe, Peskin says. As scientists probe space and go back further in time, they can learn more about the rules that govern physics at high energies, which also tells us something about the smallest components of our world.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 4:03 pm on August 24, 2017 Permalink | Reply
    Tags: , , , , , , , , , , SURF LBNF/ DUNE, Symmetry Magazine   

    From Symmetry: “Mega-collaborations for scientific discovery” 

    Symmetry Mag

    Symmetry

    08/24/17
    Leah Poffenberger

    1
    DUNE joins the elite club of physics collaborations with more than 1000 members. Photo by Reidar Hahn, Fermilab.

    Sometimes it takes lot of people working together to make discovery possible. More than 7000 scientists, engineers and technicians worked on designing and constructing the Large Hadron Collider at CERN, and thousands of scientists now run each of the LHC’s four major experiments.

    LHC

    CERN/LHC Map

    CERN LHC Tunnel

    CERN LHC particles

    Not many experiments garner such numbers. On August 15, the Deep Underground Neutrino Experiment (DUNE) became the latest member of the exclusive clique of particle physics experiments with more than a thousand collaborators.

    Meet them all:

    3

    4,000+: Compact Muon Solenoid Detector (CMS) Experiment

    CMS is one of the two largest experiments at the LHC. It is best known for its role in the discovery of the Higgs boson.

    The “C” in CMS stands for compact, but there’s nothing compact about the CMS collaboration. It is one of the largest scientific collaborations in history. More than 4000 people from 200 institutions around the world work on the CMS detector and use its data for research.

    About 30 percent of the CMS collaboration hail from US institutions*. A remote operations center at the Department of Energy’s Fermi National Accelerator Laboratory in Batavia, Illinois, serves as a base for CMS research in the United States.

    4

    3,000+: A Toroidal LHC ApparatuS (ATLAS) Experiment

    The ATLAS experiment, the other large experiment responsible for discovering the Higgs boson at the LHC, ranks number two in number of collaborators. The ATLAS collaboration has more than 3000 members from 182 institutions in 38 countries. ATLAS and CMS ask similar questions about the building blocks of the universe, but they look for the answers with different detector designs.

    About 30 percent of the ATLAS collaboration are from institutions in the United States*. Brookhaven National Laboratory in Upton, New York, serves as the US host.

    2,000+: Linear Collider Collaboration

    Proposed LC Linear Collider schematic. Location not yet decided.

    The Linear Collider Collaboration (LCC) is different from CMS and ATLAS in that the collaboration’s experiment is still a proposed project and has not yet been built. LCC has around 2000 members who are working to develop and build a particle collider that can produce different kinds of collisions than those seen at the LHC.

    LCC members are working on two potential linear collider projects: the compact linear collider study (CLIC) at CERN and the International Linear Collider (ILC) in Japan. CLIC and the ILC originally began as separate projects, but the scientists working on both joined forces in 2013.

    Either CLIC or the ILC would complement the LHC by colliding electrons and positrons to explore the Higgs particle interactions and the nature of subatomic forces in greater detail.

    1,500+; A Large Ion Collider Experiment (ALICE)

    5

    ALICE is part of LHC’s family of particle detectors, and, like ATLAS and CMS, it too has a large, international collaboration, counting 1500 members from 154 physics institutes in 37 countries. Research using ALICE is focused on quarks, the sub-atomic particles that make up protons and neutrons, and the strong force responsible for holding quarks together.

    1,000+: Deep Underground Neutrino Experiment (DUNE)

    The Deep Underground Neutrino Experiment is the newest member of the club. This month, the DUNE collaboration surpassed 1000 collaborators from 30 countries.

    From its place a mile beneath the earth at the Sanford Underground Research Facility in South Dakota, DUNE will investigate the behavior of neutrinos, which are invisible, nearly massless particles that rarely interact with other matter. The neutrinos will come from Fermilab, 800 miles away.

    Neutrino research could help scientists answer the question of why there is an imbalance between matter and antimatter in the universe. Groundbreaking for DUNE occurred on July 21, and the experiment will start taking data in around 2025.

    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

    Honorable mentions

    A few notable collaborations have made it close to 1000 but didn’t quite make the list. LHCb, the fourth major detector at LHC, boasts a collaboration 800 strong.

    CERN/LHCb

    Over 700 collaborators work on the Belle II experiment at KEK in Japan, which will begin taking data in 2018, studying the properties of B mesons, particles that contain a bottom quark.

    Belle II super-B factory experiment takes shape at KEK
    5

    The 600-member SLAC/Babar collaboration at SLAC National Accelerator Laboratory also studies B mesons.

    SLAC/Babar

    STAR, a detector at Brookhaven National Laboratory that probes the conditions of the early universe, has more than 600 collaborators from 55 institutions.

    BNL/RHIC Star Detector

    The CDF and DZero collaborations at Fermilab, best known for their co-discovery of the top quark in 1995, had about 700 collaborators at their peak.

    FNAL/Tevatron DZero detector

    FNAL/Tevatron CDF detector

    *Among the reasons why I started this blog was that this level of U.S. involvement was invisible in our highly vaunted press. CERN had taken over HEP from FNAL. Our idiot Congress in 1993 had killed off the Superconducting Super Collider. So it looked like we had given up. But BNL had 600 people on ATLAS. FNAL had 1000 people on CMS. So we were far from dead in HEP, just invisible. So, I had a story to tell. Today I have 1000 readers. Not too shabby for Basic and Applied Science.

    See the full article here .

    Please help promote STEM in your local schools.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 3:03 pm on August 22, 2017 Permalink | Reply
    Tags: , , Newer cheaper approaches, , , Symmetry Magazine   

    From Symmetry: “Expanding the search for dark matter” 

    Symmetry Mag

    Symmetry

    08/22/17
    Lori Ann White

    At a recent meeting, scientists shared ideas for searching for dark matter on the (relative) cheap.

    Dark matter halo Image credit: Virgo consortium / A. Amblard / ESA

    Thirty-one years ago, scientists made their first attempt to find dark matter with a particle detector in a South Dakota mine.

    Since then, researchers have uncovered enough clues to think dark matter makes up approximately 26.8 percent of all the matter and energy in the universe. They think it forms a sort of gravitational scaffolding for the galaxies and galaxy clusters our telescopes do reveal, shaping the structure of our universe while remaining unseen.

    These conclusions are based on indirect evidence such as the behavior of galaxies and galaxy clusters. Direct detection experiments—ones designed to actually sense a dark matter particle pinging off the nucleus of an atom—have yet to find what they’re looking for. Nor has dark matter been seen at the Large Hadron Collider. That invisible, enigmatic material, that Greta Garbo of particle physics, still wants to be alone.

    It could be that researchers are just looking in the wrong place. Much of the search for dark matter has focused on particles called WIMPs, weakly interacting massive particles. But interest in WIMP alternatives has been growing, prompting the development of a variety of small-scale research projects to investigate some of the most promising prospects.

    In March more than 100 scientists met at the University of Maryland for “Cosmic Visions: New Ideas in Dark Matter,” a gathering to take the pulse of the post-WIMP dark matter landscape for the Department of Energy. That pulse was surprisingly strong. Organizers recently published a white paper detailing the results.

    The conference came about partly because, “it seemed a good time to get everyone together to see what each experiment was doing, where they reinforced each other and where they did something new,” says Natalia Toro, a theorist at SLAC National Accelerator Laboratory and a member of the Cosmic Visions Scientific Advisory Committee. What she and many other participants didn’t expect, Toro says, was just how many good ideas would be presented.

    Almost 50 experiments in various stages of development were presented during three days of talks, and a similar number of potential experiments were discussed.

    Some of the experiments presented would be designed to look for dark matter particles that are lighter than traditional WIMPs, or for the new fundamental forces through which such particles could interact. Others would look for oscillating forces produced by dark matter particles trillions of times lighter than the electron. Still others would look for different dark matter candidates, such as primordial black holes.

    The scientists at the workshop were surprised by how small and relatively inexpensive many of the experiments could be, says Philip Schuster, a particle theorist at SLAC National Accelerator Laboratory.

    “‘Small’ and ‘inexpensive’ depend on what technology you’re using, of course,” Schuster says. DOE is prepared to provide funding to the tune of $10 million (still a fraction of the cost of a current WIMP experiment), and many of the experiments could cost in the $1 to $2 million range.

    Several factors work together to lessen the cost. For example, advances in detector technology and quantum sensors have made technology cheaper. Then there are small detectors that can be placed at already-existing large facilities like the Heavy Photon Search, a dark-sector search at Jefferson Lab. “It’s basically a table-top detector, as opposed to CMS and ATLAS at the Large Hadron Collider, which took years to build and weigh as much as a battleship,” Schuster says.

    Experimentalist Joe Incandela of the University of California, Santa Barbara and one of the coordinators of the Cosmic Visions effort, has a simple explanation for this current explosion of ideas. “There’s a good synergy between the technology and interest in dark matter,” he says.

    Incandela says he is feeling the synergy himself. He is a former spokesperson for CMS, a battleship-class experiment in which he continues to play an active role while also developing the Light Dark Matter Experiment, which would use a high-resolution silicon-based calorimeter that he originally helped develop for CMS to search for an alternative to WIMPs.

    “It occurred to me that this calorimeter technology could very useful for low-mass dark matter searches,” he says. “My hope is that, starting soon, and spanning roughly five years, the funding—and not very much is needed—will be available to support experiments that can cover a lot more of the landscape where dark matter may be hiding. It’s very exciting.”

    See the full article here .

    Please help promote STEM in your local schools.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 1:34 pm on August 15, 2017 Permalink | Reply
    Tags: , , , , , Symmetry Magazine   

    From Symmetry: “All about supernovae” 2015 

    Symmetry Mag

    Symmetry

    08/25/15 [Why now?]
    Ali Sundermier

    1
    Crab nebula

    Somewhere in the cosmos, a star is reaching the end of its life.

    Maybe it’s a massive star, collapsing under its own gravity. Or maybe it’s a dense cinder of a star, greedily stealing matter from a companion star until it can’t handle its own mass.

    Whatever the reason, this star doesn’t fade quietly into the dark fabric of space and time. It goes kicking and screaming, exploding its stellar guts across the universe, leaving us with unparalleled brightness and a tsunami of particles and elements. It becomes a supernova. Here are ten facts about supernovae that will blow your mind.

    1. The oldest recorded supernova dates back almost 2000 years

    In 185 AD, Chinese astronomers noticed a bright light in the sky. Documenting their observations in the Book of Later Han, these ancient astronomers noted that it sparkled like a star, appeared to be half the size of a bamboo mat and did not travel through the sky like a comet. Over the next eight months this celestial visitor slowly faded from sight. They called it a “guest star.”

    Two millennia later, in the 1960s, scientists found hints of this mysterious visitor in the remnants of a supernova approximately 8000 light-years away. The supernova, SN 185, is the oldest known supernova recorded by humankind.

    2
    SN185. Wikipedia

    3
    2. Many of the elements we’re made of come from supernovae

    Everything from the oxygen you’re breathing to the calcium in your bones, the iron in your blood and the silicon in your computer was brewed up in the heart of a star.

    As a supernova explodes, it unleashes a hurricane of nuclear reactions. These nuclear reactions produce many of the building blocks of the world around us. The lion’s share of elements between oxygen and iron comes from core-collapse supernovae, those massive stars that collapse under their own gravity. They share the responsibility of producing the universe’s iron with thermonuclear supernovae, white dwarves that steal mass from their binary companions. Scientists also believe supernovae are a key site for the production of most of the elements heavier than iron.

    4

    3. Supernovae are neutrino factories

    In a 10-second period, a core-collapse supernova will release a burst of more than 1058 neutrinos, ghostly particles that can travel undisturbed through almost everything in the universe.

    Outside of the core of a supernova, it would take a light-year of lead to stop a neutrino. But when a star explodes, the center can become so dense that even neutrinos take a little while to escape. When they do escape, neutrinos carry away 99 percent of the energy of the supernova.

    Scientists watch for that burst of neutrinos using an early warning system called SNEWS. SNEWS is a network of neutrino detectors across the world. Each detector is programmed to send a datagram to a central computer whenever it sees a burst of neutrinos. If more than two experiments observe a burst within 10 seconds, the computer issues an automatic alert to the astronomical community to look out for an exploding star.

    But you don’t have to be an expert astronomer to receive an alert. Anyone can sign up to be among the first to know that a star’s core has collapsed.

    5
    4. Supernovae are powerful particle accelerators

    Supernovae are natural space laboratories; they can accelerate particles to at least 1000 times the energy of particles in the Large Hadron Collider, the most powerful collider on Earth.

    The interaction between the blast of a supernova and the surrounding interstellar gas creates a magnetized region, called a shock. As particles move into the shock, they bounce around the magnetic field and get accelerated, much like a basketball being dribbled closer and closer to the ground. When they are released into space, some of these high-energy particles, called cosmic rays, eventually slam into our atmosphere, colliding with atoms and creating showers of secondary particles that rain down on our heads.

    5. Supernovae produce radioactivity

    In addition to forging elements and neutrinos, the nuclear reactions inside of supernovae also cook up radioactive isotopes. Some of this radioactivity emits light signals, such as gamma rays, that we can see in space.

    This radioactivity is part of what makes supernovae so bright. It also provides us with a way to determine if any supernovae have blown up near Earth. If a supernova occurred close enough to our planet, we’d be sprayed with some of these unstable nuclei. So when scientists come across layers of sediment with spikes of radioactive isotopes, they know to investigate whether what they’ve found was spit out by an exploding star.

    In 1998, physicists analyzed crusts from the bottom of the ocean and found layers with a surge of 60Fe, a rare radioactive isotope of iron that can be created in copious amounts inside supernovae. Using the rate at which 60Fe decays over time, they were able to calculate how long ago it landed on Earth. They determined that it was most likely dumped on our planet by a nearby supernova about 2.8 million years ago.

    6
    6. A nearby supernova could cause a mass extinction

    If a supernova occurred close enough, it could be pretty bad news for our planet. Although we’re still not sure about all the ways being in the midst of an exploding star would affect us, we do know that supernovae emit truckloads of high-energy photons such as X-rays and gamma rays. The incoming radiation would strip our atmosphere of its ozone. All of the critters in our food chain from the bottom up would fry in the sun’s ultraviolet rays until there was nothing left on our planet but dirt and bones.

    Statistically speaking, a supernova in our own galaxy has been a long time coming.

    Supernovae occur in our galaxy at a rate of about one or two per century. Yet we haven’t seen a supernova in the Milky Way in around 400 years. The most recent nearby supernova was observed in 1987, and it wasn’t even in our galaxy. It was in a nearby satellite galaxy called the Large Magellanic Cloud.

    But death by supernova probably isn’t something you have to worry about in your lifetime, or your children’s or grandchildren’s or great-great-great-grandchildren’s lifetime. IK Pegasi, the closest candidate we have for a supernova, is 150 light-years away—too far to do any real damage to Earth.

    Even that 2.8-million-year-old supernova that ejected its radioactive insides into our oceans was at least 100 light-years from Earth, which was not close enough to cause a mass-extinction. The physicists deemed it a “near miss.”

    7
    7. Supernovae light can echo through time

    Just as your voice echoes when its sound waves bounce off a surface and come back again, a supernova echoes in space when its light waves bounce off cosmic dust clouds and redirect themselves toward Earth.

    Because the echoed light takes a scenic route to our planet, this phenomenon opens a portal to the past, allowing scientists to look at and decode supernovae that occurred hundreds of years ago. A recent example of this is SN1572, or Tycho’s supernova, a supernova that occurred in 1572. This supernova shined brighter than Venus, was visible in daylight and took two years to dim from the sky.

    In 2008, astronomers found light waves originating from the cosmic demolition site of the original star. They determined that they were seeing light echoes from Tycho’s supernova. Although the light was 20 billion times fainter than what astronomer Tycho Brahe observed in 1572, scientists were able to analyze its spectrum and classify the supernova as a thermonuclear supernova.

    More than four centuries after its explosion, light from this historical supernova is still arriving at Earth.

    8
    8. Supernovae were used to discover dark energy

    Because thermonuclear supernovae are so bright, and because their light brightens and dims in a predictable way, they can be used as lighthouses for cosmology.

    In 1998, scientists thought that cosmic expansion, initiated by the big bang, was likely slowing down over time. But supernova studies suggested that the expansion of the universe was actually speeding up.

    Scientists can measure the true brightness of supernovae by looking at the timescale over which they brighten and fade. By comparing how bright these supernovae appear with how bright they actually are, scientists are able to determine how far away they are.

    Scientists can also measure the increase in the wavelength of a supernova’s light as it moves farther and farther away from us. This is called the redshift.

    Comparing the redshift with the distances of supernovae allowed scientists to infer how the rate of expansion has changed over the history of the universe. Scientists believe that the culprit for this cosmic acceleration is something called dark energy.

    9. Supernovae occur at a rate of approximately 10 per second

    By the time you reach the end of this sentence, it is likely a star will have exploded somewhere in the universe.

    As scientists evolve better techniques to explore space, the number of supernovae they discover increases. Currently they find over a thousand supernovae per year.

    But when you look deep into the night sky at bright lights shining from billions of light-years away, you’re actually looking into the past. The supernovae that scientists are detecting stretch back to the very beginning of the universe. By adding up all of the supernovae they’ve observed, scientists can figure out the rate at which supernovae occur across the entire universe.

    Scientists estimate about 10 supernovae occur per second, exploding in space like popcorn in the microwave.

    10
    10. We’re about to get much better at detecting far-away supernovae

    Even though we’ve been aware of these exploding stars for millennia, there’s still so much we don’t know about them. There are two known types of supernovae, but there are many different varieties that scientists are still learning about.

    Supernovae could result from the merger of two white dwarfs. Alternatively, the rotation of a star could create a black hole that accretes material and launches a jet through the star. Or the density of a star’s core could be so high that it starts creating electron-positron pairs, causing a chain reaction in the star.

    Right now, scientists are mapping the night sky with the Dark Energy Survey, or DES. Scientists can discover new supernova explosions by looking for changes in the images they take over time.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    Another survey currently going on is the All-Sky Automated Survey for Supernovae, or the ASAS-SN, which recently observed the most luminous supernova ever discovered.

    ASAS-SN Brutus

    In 2019, the Large Synoptic Survey Telescope, or LSST, will revolutionize our understanding of supernovae. LSST is designed to collect more light and peer deeper into space than ever before. It will move rapidly across the sky and take more images in larger chunks than previous surveys. This will increase the number of supernovae we see by hundreds of thousands per year.

    LSST


    LSST Camera, built at SLAC



    LSST telescope, currently under construction at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    Studying these astral bombs will expand our knowledge of space and bring us even closer to understanding not just our origin, but the cosmic reach of the universe.

    See the full article here .

    Please help promote STEM in your local schools.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 4:07 pm on August 11, 2017 Permalink | Reply
    Tags: , , , FAST- Fermilab Accelerator Science and Technology facility, Symmetry Magazine   

    From Symmetry: “Think FAST” 

    Symmetry Mag

    Symmetry

    08/10/17
    Leah Poffenberger

    1
    Photo by Reidar Hahn, Fermilab

    The new Fermilab Accelerator Science and Technology [FAST] facility at Fermilab looks to the future of accelerator science.

    Unlike most particle physics facilities, the new Fermilab Accelerator Science and Technology facility (FAST) wasn’t constructed to find new particles or explain basic physical phenomena. Instead, FAST is a kind of workshop—a space for testing novel ideas that can lead to improved accelerator, beamline and laser technologies.

    Historically, accelerator research has taken place on machines that were already in use for experiments, making it difficult to try out new ideas. Tinkering with a physicist’s tools mid-search for the secrets of the universe usually isn’t a great idea. By contrast, FAST enables researchers to study pieces of future high-intensity and high-energy accelerator technology with ease.

    “FAST is specifically aiming to create flexible machines that are easily reconfigurable and that can be accessed on very short notice,” says Alexander Valishev, head of department that manages FAST. “You can roll in one experiment and roll the other out in a matter of days, maybe months, without expensive construction and operation costs.”

    This flexibility is part of what makes FAST a useful place for training up new accelerator scientists. If a student has an idea, or something they want to study, there’s plenty of room for experimentation.

    “We want students to come and do their thesis research at FAST, and we already have a number of students working.” Valishev says. “We have already had a PhD awarded on the basis of work done at FAST, but we want more of that.”

    2
    This yellow cyromodule will house the superconducting cavities that take the beam’s energy from 50 to 300 MeV. Courtesy of Fermilab.

    Small ring, bright beam

    FAST will eventually include three parts: an electron injector, a proton injector and a particle storage ring called the Integrable Optics Test Accelerator, or IOTA. Although it will be small compared to other rings—only 40 meters long, while Fermilab’s Main Injector has a circumference of 3 kilometers—IOTA will be the centerpiece of FAST after its completion in 2019. And it will have a unique feature: the ability to switch from being an electron accelerator to a proton accelerator and back again.

    “The sole purpose of this synchrotron is to test accelerator technology and develop that tech to test ideas and theories to improve accelerators everywhere,” says Dan Broemmelsiek, a scientist in the IOTA/FAST department.

    One aspect of accelerator technology FAST focuses on is creating higher-intensity or “brighter” particle beams.

    Brighter beams pack a bigger particle punch. A high-intensity beam could send a detector twice as many particles as is usually possible. Such an experiment could be completed in half the time, shortening the data collection period by several years.

    IOTA will test a new concept for accelerators called integrable optics, which is intended to create a more concentrated, stable beam, possibly producing higher intensity beams than ever before.

    “If this IOTA thing works, I think it could be revolutionary,” says Jamie Santucci, an engineering physicist working on FAST. “It’s going to allow all kinds of existing accelerators to pack in way more beam. More beam, more data.”

    3
    The beam starts here: Once electrons are sent down the beamline, they pass through the a set of solenoid magnets—the dark blue rings—before entering the first two superconducting cavities. Courtesy of Fermilab.

    Maximum energy milestone

    Although the completion of IOTA is still a few years away, the electron injector will reach a milestone this summer: producing an electron beam with the energy of 300 million electronvolts (MeV).

    “The electron injector for IOTA is a research vehicle in its own right,” Valishev says. It provides scientists a chance to test superconducting accelerators, a key piece of technology for future physics machines that can produce intense acceleration at relatively low power.

    “At this point, we can measure things about the beam, chop it up or focus it,” Broemmelsiek says. “We can use cameras to do beam diagnostics, and there’s space here in the beamline to put experiments to test novel instrumentation concepts.”

    The electron beam’s previous maximum energy of 50 MeV was achieved by passing the beam through two superconducting accelerator cavities and has already provided opportunities for research. The arrival of the 300 MeV beam this summer—achieved by sending the beam through another eight superconducting cavities—will open up new possibilities for accelerator research, with some experiments already planned to start as soon as the beam is online.

    4
    Electronics for IOTA. Chip Edstrom.

    FAST forward

    The third phase of FAST, once IOTA is complete, will be the construction of the proton injector.

    “FAST is unique because we will specifically target creating high-intensity proton beams,” Valishev says.

    This high-intensity proton beam research will directly translate to improving research into elusive particles called neutrinos, Fermilab’s current focus.

    “In five to 10 years, you’ll be talking to a neutrino guy and they’ll go, ‘I don’t know what the accelerator guys did, but it’s fabulous. We’re getting more neutrinos per hour than we ever thought we would,’” Broemmelsiek says.

    Creating new accelerator technology is often an overlooked area in particle physics, but the freedom to try out new ideas and discover how to build better machines for research is inherently rewarding for people who work at FAST.

    “Our business is science, and we’re supposed to make science, and we work really hard to do that,” Broemmelsiek says. “But it’s also just plain ol’ fun.”

    See the full article here .

    Please help promote STEM in your local schools.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 3:17 pm on August 11, 2017 Permalink | Reply
    Tags: , SuperCDMS SNOLAB, Symmetry Magazine, WIMPS search   

    From Symmetry: “A new search for dark matter 6800 feet underground” 

    Symmetry Mag

    Symmetry

    08/08/17
    Manuel Gnida

    Prototype tests of the future SuperCDMS SNOLAB experiment are in full swing.

    1
    Chris Smith/SLAC National Accelerator Laboratory)

    When an extraordinarily sensitive dark matter experiment goes online at one of the world’s deepest underground research labs, the chances are better than ever that it will find evidence for particles of dark matter—a substance that makes up 85 percent of all matter in the universe but whose constituents have never been detected.

    The heart of the experiment, called SuperCDMS SNOLAB, will be one of the most sensitive detectors for hypothetical dark matter particles called WIMPs, short for “weakly interacting massive particles.” SuperCDMS SNOLAB is one of two next-generation experiments (the other one being an experiment called LZ) selected by the US Department of Energy and the National Science Foundation to take the search for WIMPs to the next level, beginning in the early 2020s.

    SuperCDMS, at SNOLAB (Vale Inco Mine, Sudbury, Canada)

    “The experiment will allow us to enter completely unexplored territory,” says Richard Partridge, head of the SuperCDMS SNOLAB group at the Kavli Institute for Particle Astrophysics and Cosmology, a joint institute of Stanford University and SLAC National Accelerator Laboratory. “It’ll be the world’s most sensitive detector for WIMPs with relatively low mass, complementing LZ, which will look for heavier WIMPs.”

    LBNL LZ project at SURF

    The experiment will operate deep underground at Canadian laboratory SNOLAB inside a nickel mine near the city of Sudbury, where 6800 feet of rock provide a natural shield from high-energy particles from space, called cosmic rays. This radiation would not only cause unwanted background in the detector; it would also create radioactive isotopes in the experiment’s silicon and germanium sensors, making them useless for the WIMP search. That’s also why the experiment will be assembled from major parts at its underground location.

    A detector prototype is currently being tested at SLAC, which oversees the efforts of the SuperCDMS SNOLAB project.

    Colder than the universe

    The only reason we know dark matter exists is that its gravity pulls on regular matter, affecting how galaxies rotate and light propagates. But researchers believe that if WIMPs exist, they could occasionally bump into normal matter, and these collisions could be picked up by modern detectors.

    SuperCDMS SNOLAB will use germanium and silicon crystals in the shape of oversized hockey pucks as sensors for these sporadic interactions. If a WIMP hits a germanium or silicon atom inside these crystals, two things will happen: The WIMP will deposit a small amount of energy, causing the crystal lattice to vibrate, and it’ll create pairs of electrons and electron deficiencies that move through the crystal and alter its electrical conductivity. The experiment will measure both responses.

    “Detecting the vibrations is very challenging,” says KIPAC’s Paul Brink, who oversees the detector fabrication at Stanford. “Even the smallest amounts of heat cause lattice vibrations that would make it impossible to detect a WIMP signal. Therefore, we’ll cool the sensors to about one hundredth of a Kelvin, which is much colder than the average temperature of the universe.”

    These chilly temperatures give the experiment its name: CDMS stands for “Cryogenic Dark Matter Search.” (The prefix “Super” indicates that the experiment is more sensitive than previous detector generations.)

    The use of extremely cold temperatures will be paired with sophisticated electronics, such as transition-edge sensors that switch from a superconducting state of zero electrical resistance to a normal-conducting state when a small amount of energy is deposited in the crystal, as well as superconducting quantum interference devices, or SQUIDs, that measure these tiny changes in resistance.

    The experiment will initially have four detector towers, each holding six crystals. For each crystal material—silicon and germanium—there will be two different detector types, called high-voltage (HV) and interleaved Z-sensitive ionization phonon (iZIP) detectors. Future upgrades can further boost the experiment’s sensitivity by increasing the number of towers to 31, corresponding to a total of 186 sensors.

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    Four SuperCDMS SNOLAB iZIP detectors at the Stanford Nanofabrication Facility. Matt Cherry.

    3
    A SNOLAB Engineering Tower is installed in the dilution fridge to test cryogenic flex-cable readout configurations. Paul Brink.

    4
    High-density Vacuum Interface Board developed at Fermilab for readout of cryogenic detectors. Paul Brink.

    5
    SNOLAB prototype HV detector fabricated and packaged by Matt Cherry (SLAC) in SNOLAB prototype hardware. Matt Cherry.

    6
    SNOLAB Engineering Tower assembled by Tsuguo Aramaki (SLAC) and Xuji Zhao (Texas A&M). Paul Brink

    Working hand in hand

    The work under way at SLAC serves as a system test for the future SuperCDMS SNOLAB experiment. Researchers are testing the four different detector types, the way they are integrated into towers, their superconducting electrical connectors and the refrigerator unit that cools them down to a temperature of almost absolute zero.

    “These tests are absolutely crucial to verify the design of these new detectors before they are integrated in the experiment underground at SNOLAB,” says Ken Fouts, project manager for SuperCDMS SNOLAB at SLAC. “They will prepare us for a critical DOE review next year, which will determine whether the project can move forward as planned.” DOE is expected to cover about half of the project costs, with the other half coming from NSF and a contribution from the Canadian Foundation for Innovation.

    Important work is progressing at all partner labs of the SuperCDMS SNOLAB project. Fermi National Accelerator Laboratory is responsible for the cryogenics infrastructure and the detector shielding—both will enable searching for faint WIMP signals in an environment dominated by much stronger unwanted background signals. Pacific Northwest National Laboratory will lend its expertise in understanding background noise in highly sensitive precision experiments. A number of US universities are involved in various aspects of the project, including detector fabrication, tests, data analysis and simulation.

    The project also benefits from international partnerships with institutions in Canada, France, the UK and India. The Canadian partners are leading the development of the experiment’s data acquisition and will provide the infrastructure at SNOLAB.

    “Strong partnerships create a lot of synergy and make sure that we’ll get the best scientific value out of the project,” says Fermilab’s Dan Bauer, spokesperson of the SuperCDMS collaboration, which consists of 109 scientists from 22 institutions, including numerous universities. “Universities have lots of creative students and principal investigators, and their talents are combined with the expertise of scientists and engineers at the national labs, who are used to successfully manage and build large projects.”

    SuperCDMS SNOLAB will be the fourth generation of experiments, following CDMS-I at Stanford, CDMS-II at the Soudan mine in Minnesota, and a first version of SuperCDMS at Soudan, which completed operations in 2015.

    “Over the past 20 years we’ve been pushing the limits of our detectors to make them more and more sensitive for our search for dark matter particles,” says KIPAC’s Blas Cabrera, project director of SuperCDMS SNOLAB. “Understanding what constitutes dark matter is as fundamental and important today as it was when we started, because without dark matter none of the known structures in the universe would exist—no galaxies, no solar systems, no planets and no life itself.”

    See the full article here .

    Please help promote STEM in your local schools.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 3:30 pm on August 4, 2017 Permalink | Reply
    Tags: , , , , , , , , Symmetry Magazine   

    From Symmetry: “The birth of a black hole, live” 09/09/15 

    Symmetry Mag

    Symmetry

    09/09/15 [this is old, but a lot of sites are featuring it again.]
    Lauren Biron

    1
    NASA/CXC/M.Weiss

    Scientists hope to use neutrino experiments to watch a black hole form.

    Black holes fascinate us. We easily conjure up images of them swallowing spaceships, but we know very little about these strange objects. In fact, we’ve never even seen a black hole form. Scientists on neutrino experiments such as the upcoming Deep Underground Neutrino Experiment hope to change that.

    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

    “You’ve got to be a bit lucky,” says Mark Thomson, DUNE co-spokesperson. “But it would be one of the major discoveries in science. It would be absolutely incredible.”

    Black holes are sometimes born when a massive star, typically more than eight times the mass of our own sun, collapses. But there are a lot of questions about what exactly happens during the process: How often do these collapsing stars give rise to black holes? When in the collapse does the black hole actually develop?

    What scientists do know is that deep in the dense core of the star, protons and electrons are squeezed together to form neutrons, sending ghostly particles called neutrinos streaming out. Matter falls inward. In the textbook case, matter rebounds and erupts, leaving a neutron star. But sometimes, the supernova fails, and there’s no explosion; instead, a black hole is born.

    DUNE’s gigantic detectors, filled with liquid argon, will sit a mile below the surface in a repurposed goldmine. While much of their time will be spent looking for neutrinos sent from Fermi National Accelerator Laboratory 800 miles away, the detectors will also have the rare ability to pick up a core collapse in our Milky Way galaxy – whether or not that leads to a new black hole.

    The only supernova ever recorded by neutrino detectors occurred in in 1987, when scientists saw a total of 19 neutrinos. Scientists still don’t know if that supernova formed a black hole or a neutron star—there simply wasn’t enough data. Thomson says that if a supernova goes off nearby, DUNE could see up to 10,000 neutrinos.

    DUNE will look for a particular signature in the neutrinos picked up by the detector. It’s predicted that a black hole will form relatively early in a supernova. Neutrinos will be able to leave the collapse in great numbers until the black hole emerges, trapping everything—including light and neutrinos—in its grasp. In data terms, that means you’d get a big burst of neutrinos with a sudden cutoff.

    Neutrinos come in three types, called flavors: electron, muon and tau. When a star explodes, it emits all the various types of neutrinos, as well as their antiparticles.

    They’re hard to catch. These neutrinos arrive with 100 times less energy than those arriving from an accelerator for experiments, which makes them less likely to interact in a detector.

    Most of the currently running, large particle detectors capable of seeing supernova neutrinos are best at detecting electron antineutrinos—and not great at detecting their matter equivalents, electron neutrinos.

    “It would be a tragedy to not be ready to detect the neutrinos in full enough detail to answer key questions,” says John Beacom, director of the Center for Cosmology and Astroparticle Physics at The Ohio State University.

    Luckily, DUNE is unique. “The only one that is sensitive to a huge slug of electron neutrinos is DUNE, and that’s a function of using argon [as the detector fluid],” says Kate Scholberg, professor of physics at Duke University.

    It will take more than just DUNE to get the whole picture, though. Getting an entire suite of large, powerful detectors of different types up and running is the best way to figure out the lives of black holes, Beacom says.

    There is a big scintillator detector, JUNO, in the works in China, and plans for a huge water-based detector, Hyper-K, in Japan.

    JUNO Neutrino detector, at Kaiping, Jiangmen in Southern China

    Hyper-Kamiokande, a neutrino physics laboratory located underground in the Mozumi Mine of the Kamioka Mining and Smelting Co. near the Kamioka section of the city of Hida in Gifu Prefecture, Japan.

    Gravitational wave detectors such as LIGO could pick up additional information about the density of matter and what’s happening in the collapse.


    Caltech/MIT Advanced aLigo Hanford, WA, USA installation


    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

    Cornell SXS, the Simulating eXtreme Spacetimes (SXS) project


    Gravitational waves. Credit: MPI for Gravitational Physics/W.Benger-Zib

    ESA/eLISA the future of gravitational wave research

    “My dream is to have a supernova with JUNO, Hyper-K and DUNE all online,” Scholberg says. “It would certainly make my decade.”

    The rate at which neutrinos arrive after a supernova will tell scientists about what’s happening at the center of a core collapse—but it will also provide information about the mysterious neutrino, including how they interact with each other and potential insights as to how much the tiny particles actually weigh.

    Within the next three years, the rapidly growing DUNE collaboration will build and begin testing a prototype of the 40,000-ton liquid argon detector. This 400-ton version will be the second-largest liquid-argon experiment ever built to date. It is scheduled for testing at CERN starting in 2018.

    DUNE is scheduled to start installing the first of its four detectors in the Sanford Underground Research Facility in 2021.

    See the full article here .

    Please help promote STEM in your local schools.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 1:49 pm on August 1, 2017 Permalink | Reply
    Tags: , , , , , , , Symmetry Magazine   

    From Symmetry: “Tuning in for science” 

    Symmetry Mag

    Symmetry

    08/01/17
    By Mike Perricone

    1
    Square Kilometer Array

    The sprawling Square Kilometer Array radio telescope hunts signals from one of the quietest places on earth.

    SKA South Africa

    When you think of radios, you probably think of noise. But the primary requirement for building the world’s largest radio telescope is keeping things almost perfectly quiet.

    Radio signals are constantly streaming to Earth from a variety of sources in outer space. Radio telescopes are powerful instruments that can peer into the cosmos—through clouds and dust—to identify those signals, picking them up like a signal from a radio station. To do it, they need to be relatively free from interference emitted by cell phones, TVs, radios and their kin.

    NRAO/Karl V Jansky VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA

    That’s one reason the Square Kilometer Array is under construction in the Great Karoo, 400,000 square kilometers of arid, sparsely populated South African plain, along with a component in the Outback of Western Australia. The Great Karoo is also a prime location because of its high altitude—radio waves can be absorbed by atmospheric moisture at lower altitudes. SKA currently covers some 1320 square kilometers of the landscape.

    Even in the Great Karoo, scientists need careful filtering of environmental noise. Effects from different levels of radio frequency interference (RFI) can range from “blinding” to actually damaging the instruments. Through South Africa’s Astronomy Geographic Advantage Act, SKA is working toward “radio protection,” which would dedicate segments of the bandwidth for radio astronomy while accommodating other private and commercial RF service requirements in the region.

    “Interference affects observational data and makes it hard and expensive to remove or filter out the introduced noise,” says Bernard Duah Asabere, Chief Scientist of the Ghana team of the African Very Long Baseline Interferometry Network (African VLBI Network, or AVN), one of the SKA collaboration groups in eight other African nations participating in the project.

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    The Ghanaian and South African governments on Thursday announced the combination of ‘first light’ science observations, which confirm the successful conversion of the Ghana communications antenna from a redundant telecoms instrument into a functioning Very Long Baseline Interferometry (VLBI) radio telescope.

    Ghana is the first partner country of the African Very Large Baseline Interferometer (VLBI) Network (AVN) to complete the conversion of a communications antenna into a functioning radio telescope.

    SKA “will tackle some of the fundamental questions of our time, ranging from the birth of the universe to the origins of life,” says SKA Director-General Philip Diamond. Among the targets: dark energy, Einstein’s theory of gravity and gravitational waves, and the prevalence of the molecular building blocks of life across the cosmos.

    SKA-South Africa can detect radio spectrum frequencies from 350 megahertz to 14 gigahertz. Its partner Australian component will observe the lower-frequency scale, from 50 to 350 megahertz. Visible light, for comparison, has frequencies ranging from 400 to 800 million megahertz. SKA scientists will process radiofrequency waves to form a picture of their source.

    A precursor instrument to SKA called MeerKat (named for the squirrel-sized critters indigenous to the area), is under construction in the Karoo.

    SKA Meerkat telescope, 90 km outside the small Northern Cape town of Carnarvon, SA

    This array of 16 dishes in South Africa achieved first light on June 19, 2016. MeerKAT focused on 0.01 percent of the sky for 7.5 hours and saw 1300 galaxies—nearly double the number previously known in that segment of the cosmos.

    Since then, MeerKAT met another milestone with 32 integrated antennas. MeerKat will also reach its full array of 64 dishes early next year, making it one of the world’s premier radio telescopes. MeerKAT will eventually be integrated into SKA Phase 1, where an additional 133 dishes will be built. That will bring the total number of antennas for SKA Phase I in South Africa to 197 by 2023. So far, 32 dishes are fully integrated and are being commissioned for science operations.

    On completion of SKA 2 by 2030, the detection area of the receiver dishes will exceed 1 square kilometer, or about 11,000 square feet. Its huge size will make it 50 times more sensitive than any other radio telescope. It is expected to operate for 50 years.

    SKA is managed by a 10-nation consortium, including the UK, China, India and Australia as well as South Africa, and receives support from another 10 countries, including the US. The project is headquartered at Jodrell Bank Observatory in the UK.

    The full SKA will use radio dishes across Africa and Australia, and collaboration members say it will have a farther reach and more detailed images than any existing radio telescope.

    Murchison Widefield Array,SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO)

    SKA/ASKAP radio telescope at the Murchison Radio-astronomy Observatory (MRO) in Mid West region of Western Australia

    In preparation for the SKA, South Africa and its partner countries developed AVN to establish a network of radiotelescopes across the African continent. One of its projects is the refurbishing of redundant 30-meter-class antennas, or building new ones across the partner countries, to operate as networked radio telescopes.

    4
    Hartebeesthoek Radio Astronomy Observatory in Gauteng.

    The first project of its kind is the AVN Ghana project, where an idle 32-meter diameter dish has been refurbished and revamped with a dual receiver system at 5 and 6.7 gigahertz central frequencies for use as a radio telescope. The dish was previously owned and operated by the government and the company Vodafone Ghana as a telecommunications facility. Now it will explore celestial objects such as extragalactic nebulae, pulsars and other RF sources in space, such as molecular clouds, called masers.

    Asabere’s group will be able to tap into areas of SKA’s enormous database (several supercomputers’ worth) over the Internet. So will groups in Botswana, Kenya, Madagascar, Mauritius, Mozambique, Namibia and Zambia. SKA is also offering extensive outreach in participating countries and has already awarded 931 scholarships, fellowships and grants.

    Other efforts in Ghana include introducing astronomy in the school curricula, training students in astronomy and related technologies, doing outreach in schools and universities, receiving visiting students at the telescope site and hosting programs such as the West African International Summer School for Young Astronomers taking place this week.

    Asabere, who achieved his advanced degrees in Sweden (Chalmers University of Technology) and South Africa (University of Johannesburg), would like to see more students trained in Ghana, and would like get more researchers on board. He also hopes for the construction of the needed infrastructure, more local and foreign partnerships and strong governmental backing.

    “I would like the opportunity to practice my profession on my own soil,” he says.

    That day might not be far beyond the horizon. The Leverhulme-Royal Society Trust and Newton Fund in the UK are co-funding extensive human capital development programs in the SKA-AVN partner countries. A seven-member Ghanaian team, for example, has undergone training in South Africa and has been instructed in all aspects of the project, including the operation of the telescope.

    Several PhD students and one MSc student from Ghana have received SKA-SA grants to pursue further education in astronomy and engineering. The Royal Society has awarded funding in collaboration with Leeds University to train two PhDs and 60 young aspiring scientists in the field of astrophysics.

    Based on the success of the Leverhulme-Royal Society program, a joint UK-South Africa Newton Fund intervention (DARA—the Development in Africa with Radio Astronomy) has since been initiated in other partner countries to grow high technology skills that could lead to broader economic development in Africa.

    As SKA seeks answers to complex questions over the next five decades, there should be plenty of opportunities for science throughout the Southern Hemisphere. Though it lives in one of the quietest places, SKA hopes to be heard loud and clear.

    See the full article here .

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