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  • richardmitnick 1:08 pm on October 22, 2014 Permalink | Reply
    Tags: , , , , Neutrinos, ,   

    From FNAL: “From the Office of Campus Strategy and Readiness – Building the future of Fermilab” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Wednesday, Oct. 22, 2014
    ro
    Randy Ortgiesen, head of OCSR, wrote this column.

    As Fermilab and the Department of Energy continue to aggressively “make ready the laboratory” for implementing P5’s recommendations, I can’t help reflecting on all that has recently been accomplished to support the lab’s future — both less visible projects and the big stuff. As we continue to build on these accomplishments, it’s worth noting their breadth and how much headway we’ve made.

    The development of the Muon Campus is proceeding at a healthy clip. Notable in its progress is the completion of the MC-1 Building and the cryogenic systems that support the Muon g-2 experiment. The soon-to-launch beamline enclosure construction project and soon-to-follow Mu2e building is also significant. And none of this could operate without the ongoing, complex accelerator work that will provide beam to these experiments.

    Repurposing of the former CDF building for future heavy-assembly production space and offices is well under way, with more visible exterior improvements to begin soon.

    The new remote operations center, ROC West, is open for business. Several experiments already operate from its new location adjacent to the Wilson Hall atrium.

    The Wilson Street entrance security improvements, including a new guardhouse, are also welcome additions to improved site aesthetics and security operations. Plans for a more modern and improved Pine Street entrance are beginning as well.

    The fully funded Science Laboratory Infrastructure project to replace the Master Substation and critical portions of the industrial cooling water system will mitigate the lab’s largest infrastructure vulnerability for current and future lab operations. Construction is scheduled to start in summer 2015.

    The short-baseline neutrino program is expected to start utility and site preparation very soon, with the start of the detector building construction following shortly thereafter. This is an important and significant part of the near-term future of the lab.

    The start of a demolition program for excess older and inefficient facilities is very close. The program will begin with a portion of the trailers at both the CDF and DZero trailer complexes.

    Space reconfiguration in Wilson Hall to house the new Neutrino Division and LBNF project offices is in the final planning stage and will also be starting soon.

    The atrium improvements, with the reception desk, new lighting and more modern furniture create a more welcoming atmosphere.

    And I started the article by mentioning planning for the “big stuff.” The big stuff, as you may know, includes the lab’s highest-priority project in developing a new central campus. This project is called the Center for Integrated Engineering Research, to be located just west of Wilson Hall. It will consolidate engineering resources from across the site to most efficiently plan for, construct and operate the P5 science projects. The highest-priority Technical Campus project, called the Industrial Center Building Addition, is urgently needed to expand production capacity for the equipment required for future science projects. And lastly the Scientific Hostel, or guest house, for which plans are also under way, will complete the Central Campus theme to “eat-sleep-work to drive discovery.”

    See the full article here.

    Fermilab Campus

    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.

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  • richardmitnick 9:30 am on October 13, 2014 Permalink | Reply
    Tags: , , Neutrinos   

    From FNAL: “Fermilab hosts international workshop on neutrino beams” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Monday, Oct. 13, 2014
    Rich Blaustein

    team
    Fermilab recently hosted scientists from all over the world for a workshop on neutrino beams and instrumentation. Photo: Reidar Hahn

    From Sept. 23-26, Fermilab hosted the Ninth International Workshop on Neutrino Beams and Instrumentation (NBI 2014). Fermilab’s Alberto Marchionni, neutrino physicist in the Accelerator Division, and Bob Zwaska, accelerator physicist in the Accelerator Physics Center, co-chaired NBI 2014. Marchionni and Zwaska said the conference was a big success, with discussions chiefly concerning target materials, facility designs with increased neutrino beam power, safety and international cooperation — all with a heavy focus on long-baseline experiments.

    The workshop series was initiated in 1999 when Japanese scientists, who had just started their neutrino beam for the world’s first long-baseline experiment, sought international input. Participants from other countries understood the value of the workshop and supported its continuation.

    “When you start designing a beamline, you present at this gathering,” Marchionni said.

    He provided an example of earlier NBI discussions on Fermilab’s NuMI neutrino beamline informing the subsequent J-PARC (Japan Proton Accelerator Research Complex) neutrino beamline design.

    Zwaska added that the workshop is especially relevant to Fermilab.

    “Whether with neutrino oscillation experiments — the long-baseline ones, the short-baseline ones — or scattering experiments, neutrino experimentation is central to what Fermilab does,” Zwaska said. “The exchange of information at the workshop is the most efficient way to enhance our skills to conduct these experiments and build neutrino beamlines. There is no book for how to make these beams.”

    A good part of NBI 2014 focused on operations, including safety. Zwaska said that, just like other scientific operations, neutrino beam facilities age, and that access, upkeep and repair of critical components of neutrino beamline systems was an important focus at the workshop.

    Participants also discussed the near- and long-term future, in which beamlines will operate at higher power levels and eventually at megawatt intensities, as in the case of the proposed Long-Baseline Neutrino Facility being developed at Fermilab.

    “We are ready to face the challenge in 2015, when we have to go significantly beyond the power we achieved with NuMI this past year of 360 kilowatts,” Marchionni said, referring to recent improvements to the Fermilab accelerator complex. This will be very auspicious for particle physics, he explained, because Fermilab’s NOvA experiment, matched with data from the other neutrino experiments, will begin to address pressing questions about our universe, such as its matter-antimatter imbalance.

    Like previous NBIs, the importance of international cooperation was underscored at the workshop. Marchionni said international cooperation will be even more important for the higher power operations of the future.

    “The neutrino beam is really a part of the physics of the experiment,” Marchionni said. “In part, because of differing viewpoints like those you find at NBIs, you come up with the best solutions in experiments that have international participation. The same is true for the neutrino beam.”

    The next NBI workshop will take place in Japan in 2016.

    See the full article here.

    Fermilab Campus

    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.

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  • richardmitnick 12:45 pm on October 9, 2014 Permalink | Reply
    Tags: , , Neutrinos   

    From FNAL: “Physics in a Nutshell – Neutrinos meet liquid argon” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Thursday, Oct. 9, 2014
    Tia Miceli

    Fermilab’s flagship effort is its neutrino program, which is ramping up to be the strongest in the world. This means creating the world’s best neutrino detectors. To that end, scientists at Fermilab are pursuing one hot technology that is lighting up neutrino physics, detection based on cryogenic liquid argon.

    tube
    Like neon, argon is used to make colorful lighted signs. Particle physicists are now putting argon to a far more exciting use: detecting neutrinos. Image: P Slawinski

    At first, argon seems to be a pretty boring element. As a noble gas, it does not react chemically. Making up one percent of our atmosphere, it is its third most common component, surpassed only by nitrogen and oxygen. But don’t let its mundane properties fool you. When we cool it down to extremely cold temperatures, it turns into a liquid with incredible properties for cutting-edge neutrino detectors.

    For particle physics, perhaps liquid argon’s most important feature is that it acts as both a target and detector for neutrinos, although it isn’t the only material that can be used this way. The Super-Kamiokande experiment in Japan used water stored in a deep-underground tank as large as Wilson Hall to detect neutrinos. Here at Fermilab, the MiniBooNE experiment used a giant sphere of oil that operated much the same way as Super-Kamiokande’s tank.

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    Super-Kamiokande experiment

    mb
    The MiniBooNE experiment records a neutrino event, in this 2002 image from Fermilab. The ring of light, registered by some of more than one thousand light sensors inside the detector, indicates the collision of a muon neutrino with an atomic nuclei. Credit: Fermilab

    But with 40 protons and neutrons, liquid argon is denser than water or oil, so liquid-argon detectors see more neutrino collisions per unit volume than their oil- or water-based predecessors. That means faster measurements and consequently faster discoveries.

    Another advantage of liquid argon is that, when a neutrino interacts with it and subsequently generates charged particles, it produces two separate kinds of signals; oil- or water-based detectors produce only one. One type of signal, unique to liquid argon, results from its ability to record the charged particles’ trajectories.

    Charged particles are created in the liquid argon after a neutrino flies in and collides with an argon nucleus. The charged debris travels through the argon and easily knocks off electrons from the neighboring atoms along its path. The electronic traces in the liquid argon are pushed by an applied electric field toward an array of wires (similar to a guitar’s) on the side of the detector. The wires collect data on the particle trajectories, producing a signal.

    The second signal type is one shared with oil- and water-based detection: a flash of light. When a charged particle bumps into an argon atom’s electron, the electron transitions to a higher energy. As the electron transitions back to its original state, the excess energy is emitted as light.

    It turns out that argon is also relatively cheap. Companies liquefy air and heat it slowly. Since each of air’s components has a unique boiling temperature, they can be separated. The boiled-off argon is moved to a separate chamber where it is again condensed. The commercially available liquid argon that we buy is still not pure enough for our experiments, so once the liquid argon arrives at the lab, we filter out the remaining impurities by a factor of 10,000.

    Using a common and innocuous gas, Fermilab is establishing itself to be the world’s premier neutrino physics research center. Stay tuned to discover what secrets this technology will unlock!

    See the full article here.

    Fermilab Campus

    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.

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  • richardmitnick 6:10 pm on October 6, 2014 Permalink | Reply
    Tags: , , Neutrinos   

    From Symmetry: “500-mile neutrino experiment up and running” 

    Symmetry

    October 06, 2014
    Media Contacts:

    Andre Salles, Fermilab Office of Communication, media@fnal.gov, 630-840-3351
    Rhonda Zurn, University of Minnesota, rzurn@umn.edu, 612-626-7959

    Science Contacts:

    Mark Messier, NOvA co-spokesperson, messier@indiana.edu, 812-855-0236
    Gary Feldman, NOvA co-spokesperson, gfeldman@fas.harvard.edu, 617-496-1044
    Peter Shanahan, Fermilab physicist, NOvA experiment, shanahan@fnal.gov, 630-840-8378
    Marvin Marshak, Ash River Laboratory director, University of Minnesota, marshak@umn.edu, 612-624-1312

    With construction completed, the NOvA neutrino experiment has begun its probe into the mysteries of ghostly particles that may hold the key to understanding the universe.

    It’s the most powerful accelerator-based neutrino experiment ever built in the United States, and the longest-distance one in the world. It’s called NOvA, and after nearly five years of construction, scientists are now using the two massive detectors—placed 500 miles apart—to study one of nature’s most elusive subatomic particles.

    Scientists believe that a better understanding of neutrinos, one of the most abundant and difficult-to-study particles, may lead to a clearer picture of the origins of matter and the inner workings of the universe. Using the world’s most powerful beam of neutrinos, generated at the US Department of Energy’s Fermi National Accelerator Laboratory near Chicago, the NOvA experiment can precisely record the telltale traces of those rare instances when one of these ghostly particles interacts with matter.

    Construction on NOvA’s two massive neutrino detectors began in 2009. In September, the Department of Energy officially proclaimed construction of the experiment completed, on schedule and under budget.

    “Congratulations to the NOvA collaboration for successfully completing the construction phase of this important and exciting experiment,” says James Siegrist, DOE associate director of science for high energy physics. “With every neutrino interaction recorded, we learn more about these particles and their role in shaping our universe.”

    NOvA’s particle detectors were both constructed in the path of the neutrino beam sent from Fermilab in Batavia, Illinois, to northern Minnesota. The 300-ton near-detector, installed underground at the laboratory, observes the neutrinos as they embark on their near-light-speed journey through the Earth, with no tunnel needed. The 14,000-ton far-detector—constructed in Ash River, Minnesota, near the Canadian border—spots those neutrinos after their 500-mile trip and allows scientists to analyze how they change over that long distance.

    FNAL NOvA experiment

    For the next six years, Fermilab will send tens of thousands of billions of neutrinos every second in a beam aimed at both detectors, and scientists expect to catch only a few each day in the far detector, so rarely do neutrinos interact with matter.

    From this data, scientists hope to learn more about how and why neutrinos change between one type and another. The three types, called flavors, are the muon, electron and tau neutrino. Over longer distances, neutrinos can flip between these flavors. NOvA is specifically designed to study muon neutrinos changing into electron neutrinos. Unraveling this mystery may help scientists understand why the universe is composed of matter and why that matter was not annihilated by antimatter after the big bang.

    Scientists will also probe the still-unknown masses of the three types of neutrinos in an attempt to determine which is the heaviest.

    “Neutrino research is one of the cornerstones of Fermilab’s future and an important part of the worldwide particle physics program,” says Fermilab Director Nigel Lockyer. “We’re proud of the NOvA team for completing the construction of this world-class experiment, and we’re looking forward to seeing the first results in 2015.”

    The far detector in Minnesota is believed to be the largest free-standing plastic structure in the world, at 200 feet long, 50 feet high and 50 feet wide. Both detectors are constructed from PVC and filled with a scintillating liquid that gives off light when a neutrino interacts with it. Fiber optic cables transmit that light to a data acquisition system, which creates 3-D pictures of those interactions for scientists to analyze.

    The NOvA far detector in Ash River saw its first long-distance neutrinos in November 2013. The far detector is operated by the University of Minnesota under an agreement with Fermilab, and students at the university were employed to manufacture the component parts of both detectors.

    “Building the NOvA detectors was a wide-ranging effort that involved hundreds of people in several countries,” says Gary Feldman, co-spokesperson of the NOvA experiment. “To see the construction completed and the operations phase beginning is a victory for all of us and a testament to the hard work of the entire collaboration.”

    The NOvA collaboration comprises 208 scientists from 38 institutions in the United States, Brazil, the Czech Republic, Greece, India, Russia and the United Kingdom. The experiment receives funding from the US Department of Energy, the National Science Foundation and other funding agencies.

    See the full article, with video, here.

    Symmetry is a joint Fermilab/SLAC publication.


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  • richardmitnick 2:43 pm on October 3, 2014 Permalink | Reply
    Tags: , , , Neutrinos,   

    From BNL: “Brookhaven and the Daya Bay Neutrino Experiment” 

    Brookhaven Lab

    October 1, 2014
    Karen McNulty Walsh

    The Daya Bay Collaboration, an international group of scientists studying the subtle transformations of subatomic particles called neutrinos, is publishing its first results on the search for a so-called sterile neutrino, a possible new type of neutrino beyond the three known neutrino “flavors,” or types. The existence of this elusive particle, if proven, would have a profound impact on our understanding of the universe, and could impact the design of future neutrino experiments. The new results, appearing in the journal Physical Review Letters, show no evidence for sterile neutrinos in a previously unexplored mass range. Read the collaboration press release.

    db
    Daya Bay
    Daya Bay
    The U.S. Department of Energy’s Brookhaven National Laboratory plays multiple roles in the Daya Bay experiment, ranging from management to data analysis. In addition to coordinating detector engineering and design efforts and developing software and analysis techniques, Brookhaven scientists perfected the “recipe” for a very special, chemically stable liquid that fills Daya Bay’s detectors and interacts with antineutrinos. This work at Daya Bay builds on a legacy of breakthrough neutrino research by Brookhaven Lab that has resulted in two Nobel Prizes in Physics.

    team
    Members of the BNL team on the Daya Bay Neutrino Project include: (seated, from left) Penka Novakova, Laurie Littenberg, Steve Kettell, Ralph Brown, and Bob Hackenburg; (standing, from left) Zhe Wang, Chao Zhang, Jiajie Ling, David Jaffe, Brett Viren, Wanda Beriguete, Ron Gill, Mary Bishai, Richard Rosero, Sunej Hans, and Milind Diwan. Missing from the picture are: Donna Barci, Wai-Ting Chan, Chellis Chasman, Debbie Kerr, Hide Tanaka, Wei Tang, Xin Qian, Minfang Yeh, and Elizabeth Worcester.

    Comments from U.S. Daya Bay Chief Scientist Steve Kettell

    sk
    Steve Kettell

    This body of research is helping to unlock the secrets of the least understood constituents of matter—an important quest considering that neutrinos outnumber all other particle types with a billion neutrinos for every quark or electron.

    The fairly recent discovery that neutrinos have mass changes how we must think about the Standard Model of particle physics because it cannot be explained by that well-accepted description of all known particles and their interactions.

    sm
    The Standard Model of elementary particles, with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    Understanding the details of neutrino mass could have huge implications for our understanding of how the universe evolved. And those details—including how neutrinos oscillate, or switch from one flavor to another, are the essence of the research at Daya Bay and a key to unlocking these mysteries.

    The unusual properties of the known neutrinos, particularly their unique mass properties compared to other particles in the Standard Model, give us good reason to suspect that the universe may be full of such neutral particles of other flavors, such as the sterile neutrino. These particles could potentially help account for a large portion of matter in the universe that we cannot detect directly, so called dark matter.

    Daya Bay has been an exciting experiment to work on. It has been exquisitely designed and built, enabling us to make several important discoveries (first result and new result) and to search for these particles. And while the latest study from Daya Bay did not detect evidence of sterile neutrinos, it did greatly narrow the range in which we need to search. We will continue to exploit this beautiful experiment to further explore and understand the properties of the mysterious neutrino.

    The existence of neutrino mass and mixing leads to further deep questions, in particular whether neutrinos are responsible for the dominance of matter over antimatter in the universe. With the first results from Daya Bay this question now seems answerable with the long-baseline neutrino project planned at DOE’s Fermi National Accelerator Laboratory. Brookhaven scientists identified this scientific opportunity and continue to lead the development of this project, which has now been endorsed by recent national advisory panels as the highest priority domestic project in fundamental particle physics.
    See the full article here.

    BNL Campus

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 4:10 pm on October 1, 2014 Permalink | Reply
    Tags: , , Neutrinos   

    From LBL: “News Center Hide & Seek: Sterile Neutrinos Remain Elusive” 

    Berkeley Logo

    Berkeley Lab

    October 1, 2014
    Kate Greene

    The Daya Bay Collaboration, an international group of scientists studying the subtle transformations of subatomic particles called neutrinos, is publishing its first results on the search for a so-called sterile neutrino, a possible new type of neutrino beyond the three known neutrino “flavors,” or types. The existence of this elusive particle, if proven, would have a profound impact on our understanding of the universe, and could impact the design of future neutrino experiments. The new results, appearing in the journal Physical Review Letters, show no evidence for sterile neutrinos in a previously unexplored mass range.

    There is strong theoretical motivation for sterile neutrinos. Yet, the experimental landscape is unsettled—several experiments have hinted that sterile neutrinos may exist, but the others yielded null results. Having amassed one of the largest samples of neutrinos in the world, the Daya Bay Experiment is poised to shed light on the existence of sterile neutrinos.

    Daya Bay
    Daya Bay

    reacotrs
    The reactors at Daya Bay in southeast China. Credit: Kam-Biu Luk

    The Daya Bay Experiment is situated close to the Daya Bay and Ling Ao nuclear power plants in China, 55 kilometers northeast of Hong Kong. These reactors produce a steady flux of antineutrinos that the Daya Bay Collaboration scientists use for research at detectors located at varying distances from the reactors. The collaboration includes more than 200 scientists from six regions and countries.

    The Daya Bay experiment began its operation on December 24, 2011. Soon after, in March 2012, the collaboration announced its first results: the observation of a new type of neutrino oscillation—evidence that these particles mix and change flavors from one type to others—and a precise determination of a neutrino “mixing angle,” called θ13, which is a definitive measure of the mixing of at least three mass states of neutrinos.

    The fact that neutrinos have mass at all is a relatively new discovery, as is the observation at Daya Bay that the electron neutrino is a mixture of at least three mass states. While scientists don’t know the exact values of the neutrino masses, they are able to measure the differences between them, or “mass splittings.” They also know that these particles are dramatically less massive than the well-known electron, though both are members of the family of particles called “leptons.”

    These unexpected observations have led to the possibility that the electrically neutral, almost undetectable neutrino could be a special type of matter and a very important component of the mass of the universe. Given that the nature of matter and in particular the property of mass is one of the fundamental questions in science, these new revelations about the neutrino make it clear that it is important to search for other light neutral particles that might be partners of the active neutrinos, and may contribute to the dark matter of the universe.

    Search for a light sterile neutrino

    The new Daya Bay paper describes the search for such a light neutral particle, the “sterile neutrino,” by looking for evidence that it mixes with the three known neutrino types—electron, muon, and tau. If, like the known flavors, the sterile neutrino also exists as a mixture of different masses, it would lead to mixing of neutrinos from known flavors to the sterile flavor, thus giving scientists proof of its existence. That proof would show up as a disappearance of neutrinos of known flavors.

    “The signal of sterile neutrinos, if exists, can be very subtle and easily confused by fluctuations,” says Yasuhiro Nakajima, Chamberlain Fellow in the Physics Division at the U.S. Department of Energy’s Lawrence Berkeley National Lab (Berkeley Lab) and one of the corresponding authors on the paper. “This investigation required very careful examination of the data. We developed multiple analysis methods and cross checked the analyses in many aspects.”

    Measuring disappearing neutrinos isn’t as strange as it seems. In fact that’s how Daya Bay scientists detect neutrino oscillations. The scientists count how many of the millions of quadrillions of electron antineutrinos produced every second by the six China General Nuclear Power Group reactors are captured by the detectors located in three experimental halls built at varying distances from the reactors. The detectors are only sensitive to electron antineutrinos. Calculations based on the number that disappear along the way to the farthest reactor give them information about how many have changed flavors.

    image
    Photomultiplier tubes in the Daya Bay detectors. Credit: Lawrence Berkeley Nat’l Lab – Roy Kaltschmidt

    The rate at which they transform is the basis for measuring the mixing angles (for example, θ13), and the mass splitting is determined by how the rate of transformation depends on the neutrino energy and the distance between the reactor and the detector.

    That distance is also referred to as the “baseline.” With six detectors strategically positioned at three separate locations to catch antineutrinos generated from the three pairs of reactors, Daya Bay provides a unique opportunity to search for a light sterile neutrino with baselines ranging from 360 meters to 1.8 kilometers.

    Daya Bay performed its first search for a light sterile neutrino using the energy dependence of detected electron antineutrinos from the reactors. Within the searched mass range for a fourth possible mass state, Daya Bay found no evidence for the existence of a sterile neutrino.

    This data represents the best world limit on sterile neutrinos over a wide range of masses and so far supports the standard three-flavor neutrino picture. Given the importance of clarifying the existence of the sterile neutrino, there are continuous quests by many scientists and experiments. The Daya Bay’s new result remarkably narrowed down the unexplored area.

    “We continue to collect a steady stream of data with all eight antineutrino detectors in place,” says Kam-Biu Luk, co-spokesperson for the Daya Bay experiment and senior scientist in Berkeley Lab’s Physics Division and physics professor at the University of California, Berkeley. “This will allow us to hunt for sterile neutrino in an even larger virgin land in the future.”

    See the full article here.

    A U.S. Department of Energy National Laboratory Operated by the University of California

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    DOE Seal

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  • richardmitnick 2:09 pm on September 5, 2014 Permalink | Reply
    Tags: , , , Neutrinos   

    From FNAL: “Feature – Neutrinos permeate Fermilab’s past, present and future” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Friday, Sept. 5, 2014
    Troy Rummler

    It was called Target Station C. One of three stations north of Wilson Hall at the end of beamlines extending from the Main Ring (later replaced by the Tevatron), Target Station C was assigned to experiments that would require high beam intensities for investigating neutrino interactions, according to a 1968 design report.

    Fermilab Tevatron
    Tevatron at FNAL

    Within a few years, Target Station C was officially renamed the Neutrino Area. It was the first named fixed-target area and the first to be fully operational. Neutrinos and the Intensity Frontier had an early relationship with Fermilab. But why is it resurfacing now?

    “The experimental program is driven by the current state of knowledge, and that’s always changing,” said Jeffrey Appel, a retired Fermilab physicist and assistant laboratory director who started research at the lab in 1972.

    When Appel first arrived, there was intense interest in neutrinos because the weak force was poorly understood, and neutral currents were still a controversial idea. Fermilab joined forces with many institutions both in and outside the United States, and throughout the 1970s and early 1980s, neutrinos generated from protons in the Main Ring crashed through a 15-foot bubble chamber filled with super-heated liquid hydrogen. Other experiments running in parallel recorded neutrino interactions in iron and scintillator.

    “The goal was to look for the W and Z produced in neutrino interactions,” said Appel. “So the priority for getting the beam up first and the priority for getting the detectors built and installed was on that program in those days.”

    It turns out that the W and Z bosons are too massive to have been produced this way and had to wait to be discovered at colliding-beam experiments. As soon as the Tevatron was ready for colliding beams in 1985, the transition began at Fermilab from fixed-target areas to high-energy particle colliding.

    More recent revelations have shown that neutrinos have mass. These findings have raised new questions that need answers. In 1988, plans were laid to add the Main Injector to the Fermilab campus, partly to boost the capabilities of the Tevatron, but also, according to one report, because “intense beams of neutral kaons and neutrinos would provide a unique facility for CP violation and neutrino oscillation experiments.”

    Although neutrino research was a smaller fraction of the lab’s program during Tevatron operations, it was far from dormant. Two great accomplishments in neutrino research occurred in this time period: One was the most precise neutrino measurement of the strength of the weak interaction by the NuTeV experiment. The other was when the DONUT experiment achieved its goal of making the first direct observation of the tau neutrino in 2000.

    “In the ’90s most evidence of neutrinos changing flavors was coming from natural sources. But this inspired a whole new generation of accelerator-based neutrino experiments,” said Deborah Harris, co-spokesperson for the MINERvA neutrino experiment. “That’s when Fermilab changed gears to make lower-energy but very intense neutrino beams that were uniquely suited for oscillation physics.”

    In partnership with institutions around the globe, Fermilab began planning and building a suite of neutrino experiments. MiniBooNE and MINOS started running in the early 2000s and MINERvA started in 2010. MicroBooNE and NOvA are starting their runs this year.

    Now the lab is working with other institutions to establish a Long-Baseline Neutrino Facility at the laboratory and advance its short-baseline neutrino research program. As Fermilab strengthens its international partnerships in all its neutrino experiments, it is also working to position itself as the home of the world’s forefront neutrino research.

    “The combination of the completion of the Tevatron program and the new questions about neutrinos means that it’s an opportune time to redefine the focus of Fermilab,” Appel explained.

    “Everybody says: ‘It’s not like the old days,’ and it’s always true,” Appel said. “Experiments are bigger and more expensive, but people are just as excited about what they’re doing.”

    He added, “It’s different now but just as exciting, if not more so.”

    See the full article here.

    Fermilab Campus

    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.

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  • richardmitnick 11:58 am on August 29, 2014 Permalink | Reply
    Tags: , JUNO Experiment, Neutrinos,   

    From Symmetry: “Massive neutrino experiment proposed in China” 

    Symmetry

    August 29, 2014
    Calla Cofield

    China’s neutrino physics program could soon expand with a new experiment aimed at cracking a critical neutrino mystery.

    Physicists have proposed building one of the largest-ever neutrino experiments in the city of Jiangamen, China, about 60 miles outside of Hong Kong. It could help answer a fundamental question about the nature of neutrinos.

    juno
    Jiangmen Underground Neutrino Observatory

    The Jiangmen Underground Neutrino Observatory, or JUNO, gained official status in 2013 and established its collaboration this month. Scientists are currently awaiting approval to start constructing JUNO’s laboratory near the Yangjiang and Taishan nuclear power plants. If it is built, current projections anticipate it will start taking data in 2020.

    The plan is to bury the laboratory in a mountain under roughly half of a mile of rock and earth, a shield from distracting cosmic rays. From this subterranean seat, JUNO’s primary scientific goal would be to resolve the question of neutrino mass. There are three known neutrino types, or flavors: electron, muon and tau. Scientists know the difference between the masses of each neutrino, but not their specific values—so they don’t yet know which neutrino is heaviest or lightest.

    “This is very important for our understanding of the neutrino picture,” says Yifang Wang, spokesperson for JUNO and director of the Institute of High Energy Physics of the Chinese Academy of Sciences. “For almost every neutrino model, you need to know which neutrino is heavier and which one is lighter. It has an impact on almost every other question about neutrinos.”

    To reach this goal, JUNO needs to acquire a hoard of data, which requires two key elements: a large detector and a high influx of neutrinos.

    The proposed detector design is called a liquid-scintillator—the same basic set-up used to detect neutrinos for the first time in 1956. The detector consists primarily of an acrylic sphere 34.5 meters (or nearly 115 feet) in diameter, filled with fluid engineered specifically for detecting neutrinos. When a neutrino interacts with the fluid, a chain reaction creates two tiny flashes of light. An additional sphere, made of photomultiplier tubes, would surround the ceramic sphere and capture these light signals.

    The more fluid the detector has, the more neutrino interactions the experiment can expect to see. Current liquid scintillator experiments include the Borexino experiment at the Gran Sasso Laboratory in Italy, which contains 300 tons of target liquid, and KamLand in Japan, which contains a 1000-ton target. If plans go ahead, JUNO will be the largest liquid scintillator detector ever built, containing 20,000 tons of target liquid.

    To discover the mass order of the three neutrino flavors, JUNO will look specifically at electron antineutrinos produced by the two nearby nuclear power plants.

    “Only in Asia are there relatively new reactor power plants that can have four to six reactor cores in the same place,” Wang says. With the potential to run four to six cores each, the Chinese reactors would send a dense shower of neutrinos toward JUNO’s detector. Over time, a picture of the antineutrino energies would emerge. The order of the neutrino masses influences what that energy spectrum looks like.

    Experiment representatives say JUNO could reach this goal by 2026.

    It’s possible that the NOvA experiment in the United States or the T2K experiment in Japan, both of which are currently taking data, could make a measurement of the neutrino mass hierarchy before JUNO. At least four proposed experiments could also reach the same goal. But only JUNO would make the measurement via this particular approach.

    The JUNO experiment would also tackle various other questions about the nature of neutrinos and refine some previously made measurements. If a supernova went off in our galaxy, JUNO would be able to observe the neutrinos it released. JUNO would also be the largest and most sensitive detector for geoneutrinos, which are produced by the decay of radioactive elements in the earth.

    Six nations have officially joined China in the collaboration: the Czech Republic, France, Finland, Germany, Italy and Russia. US scientists are actively participating in JUNO, but the United States is not currently an official member of the collaboration.

    See the full article here.

    Symmetry is a joint Fermilab/SLAC publication.


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  • richardmitnick 11:31 am on August 29, 2014 Permalink | Reply
    Tags: , , Neutrinos   

    From Fermilab: “Physics in a Nutshell – Invisibility squared” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Friday, Aug. 29, 2014
    Jim Pivarski

    What does it mean for something to be invisible? If it does not reflect light with the right wavelengths, it is not visible to humans, though it might be detected by a specialized instrument. Neutral particles, such as the neutrons in an atom, do not interact with photons of any wavelength (unless the wavelength is small enough to resolve individual charged quarks within the neutron). Thus, they are invisible to nearly every instrument that uses electromagnetic radiation to see.

    cat
    The former presence of a cat on the patio can be inferred from where the rain didn’t land. Similarly, sterile neutrinos may be inferred from their effects on normal neutrinos, which themselves are barely visible.

    neut
    The quark structure of the neutron. (The color assignment of individual quarks is not important, only that all three colors are present.)

    However, neutrons are easy to detect in other ways. They interact through the strong and weak nuclear forces, and neutron detectors take advantage of these interactions to “see” them. Neutrinos, on the other hand, are still more invisible, since they have no constituent quarks and interact only through the weak force. Billions of neutrinos pass through every square centimeter per second, but only a handful of these per day are detectable in a room-sized instrument.

    q
    A proton, composed of two up quarks and one down quark. (The color assignment of individual quarks is not important, only that all three colors be present.)

    Now suppose there were another kind of neutrino that did not interact with the weak force. Physicists would call such a particle a sterile neutrino if it existed. How could it be detected? If something can’t be detected, does it even make sense to talk about it? Could there be a whole world of other particles, filling the same space we do, that can never be detected because they don’t interact with anything that interacts with our eyeballs?

    In principle, anything that has mass or energy can be detected because it interacts gravitationally. That is, if there were a sterile neutrino planet right next to the Earth, then it would change the way that satellites orbit: This is our gravitational detector. However, a small mass, such as an individual particle, would deflect orbits so little that it could not be detected in practice.

    Although sterile neutrinos would have no effect on ordinary matter, they could be detected through what they do to other neutrinos. Neutrinos of different types mix quantum mechanically. That is, muon neutrinos created by a muon beam can become electron neutrinos and tau neutrinos when they are detected. If there were a fourth, sterile, type of neutrino, then the visible neutrinos would also partly transition to sterile neutrinos in flight and change the fractions of the three visible types of neutrinos in the detector.

    In the mid-1990s, an experiment called LSND saw what looked like a sterile neutrino signal, so MiniBooNE, an experiment at Fermilab, studied the effect in more detail. As the MiniBooNE scientists investigated, the story got weirder: the numbers of visible neutrinos didn’t add up, but at different energies than expected. No simple explanation makes sense of the data, but it is possible that a sterile neutrino might. A future experiment, MicroBooNE, will study this phenomenon with higher sensitivity. It would be impressive if the key to new physics is an invisible particle, glimpsed only through its effect on nearly invisible particles!

    See the full article here.

    Fermilab Campus

    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.

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  • richardmitnick 11:12 am on August 29, 2014 Permalink | Reply
    Tags: , , Neutrinos   

    From Fermilab: “Frontier Science Result- ArgoNeuT 20 years later: Neutrino-induced coherent pions are back to Fermilab “ 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Friday, Aug. 29, 2014
    Edward Santos, Imperial College London, and Tingjun Yang, Fermilab

    The neutrino is known for how rarely it interacts with matter. But when it does, the interaction can take place numerous ways, and some interaction types happen more often than others. The ArgoNeuT experiment recently looked at one of the more rare cases — one that comes to only about 1 percent of all the possible ways a neutrino can interact. As one might expect, its infrequency poses a great challenge in our efforts to measure it.

    scale
    Display of an event captured in the ArgoNeuT detector. The track on the top corresponds to a muon, the one below it is a charged pion. These particles are produced by the interaction of a muon neutrino with an argon atom in the detector.

    This month, the ArgoNeuT collaboration released a new measurement of this rare interaction, called charged-current coherent pion production induced by neutrinos on nuclei. In this process, a neutrino interacts with a nucleus as a whole, producing a muon and a pion without breaking the nucleus apart or leaving it in an excited state. Seen in the detector, the events look like the one shown above, where two very forward-going tracks leave the interaction point.

    pion
    The quark structure of the pion.

    Historically, there have been only a handful of experiments that observed coherent pion production. Back in 1993, the FNAL E632 experiment, conducted using a 15-foot bubble chamber, measured interactions of this type at a neutrino energy of 70 to 90 GeV. In more recent years, the K2K and SciBooNE experiments also attempted to measure this cross section at a much lower energy (1 to 2 GeV) but found no sign of it in the charged-current channel. The null results motivated renewed interest by the theoretical community, who modified the favored models of the time and proposed new ones.

    These days, Fermilab’s ArgoNeuT and MINERvA collaborations are in hot pursuit of these interactions, measuring them using the low-energy NuMI beam. The ArgoNeuT collaboration has measured the likelihoods of charged-current pion production, reporting the interactions with neutrinos and antineutrinos at the mean energies of 3.6 GeV and 10 GeV, respectively. These measured probabilities, the results of a five-month run of antineutrino-enhanced NuMI beam, are in good agreement with theoretical predictions and are attracting much interest within the neutrino community.

    This is the first time that scientists measured the process in a liquid-argon detector and using an automated reconstruction. Researchers also once again demonstrated the potential of the liquid-argon technique for the measurement of neutrino interactions. Key pieces of this success were ArgoNeuT’s capabilities for precisely measuring the particles ejected from a neutrino interacting with an argon nucleus.

    Although ArgoNeuT’s small detector size limits the precision of this measurement, the techniques developed during this analysis will be used by future, larger experiments, such as MicroBooNE and LAr1-ND, to gain new insights into coherent pion production.

    See the full article here.

    Fermilab Campus

    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.

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