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  • richardmitnick 3:51 pm on June 4, 2014 Permalink | Reply
    Tags: , , Neutron Science, ,   

    From SLAC: “Scientists Search for Exotic Decay with Straightforward Implications” 


    SLAC Lab

    June 4, 2014
    Lori Ann White

    Search for ‘Neutrinoless Double-beta Decay” Could Reveal Valuable Information About Neutrinos

    Two years ago researchers began using a tank of liquid xenon installed more than 2,000 feet deep in a salt formation in the southeastern corner of New Mexico to study neutrinos.

    tub
    SLAC engineers Robert Conley (left) and Knut Skarpaas VIII during the delicate task of welding the xenon vessel shut. It did not yet contain liquid xenon, but, said Skarpaas, directly behind the weld were delicate cables and light detectors which had to be protected from the heat. (Courtesy EXO-200 Collaboration)

    half
    One half of the time projection chamber before being inserted in the xenon vessel. The time projection chamber detects both light and electrons that have been knocked loose from xenon atoms. (Courtesy EXO-200 Collaboration

    whole
    The completed xenon vessel, mounted and ready to be inserted into the cryostat that will keep the xenon in a liquid state (Courtesy EXO-200 Collaboration)

    They’re looking for clues to one of the biggest puzzles about the tiny particles: What is their mass? Finding the mass of the neutrino can help answer big questions such as how the universe grew into its present form.

    This tank of liquid xenon, located near Carlsbad, New Mexico in the Waste Isolation Pilot Plant (WIPP), is the Enriched Xenon Observatory – 200 (EXO-200), the most sensitive instrument of its kind in the world. In a progress report published in the journal Nature, the scientists of the EXO-200 experiment shared what two years of data tell them about the phenomenon they’re searching for: neutrinoless double-beta decay, one of the rarest processes in the universe. There’s currently no proof this type of particle decay takes place, but if it does, it can give scientists valuable information about neutrino mass.

    As the experiment is in the data-gathering phase, “It’s far too soon to tell the ultimate outcome of our search,” said Giorgio Gratta, Stanford physics professor and principal investigator for EXO-200. However, the experiment has achieved an almost threefold increase in sensitivity over their initial neutrinoless beta-decay search, the result of which was published in Physical Review Letters in 2012. Some of this increase can be attributed to having more data, but the team can also point to upgrades to the EXO-200 detector and software.

    Particle and Antiparticle: One and the Same ?

    The clues to neutrino mass the EXO-200 researchers are looking for are hidden in the way xenon transforms into the element barium. The isotope of xenon used by EXO-200, xenon-136, follows a rare variant of a well-known natural process called beta decay in which two neutrons decay simultaneously, emitting two electrons and two anti-neutrinos to create two protons, and one atom of xenon moves forward two spots in the Periodic Table, landing on barium.

    In one version of this process, called two-neutrino double-beta decay, all four particles from the two beta decays (two electrons and two anti-neutrinos) are emitted. EXO-200 was the first to see this in xenon-136; they published the result in Physical Review Letters in 2011.

    That leaves the possibility of neutrinoless double-beta decay, the variant EXO-200 was designed to detect. In this version the two anti-neutrinos never appear. They annihilate each other before they can escape. This would confirm to researchers that neutrinos, unlike other particles, are their own antiparticles. (The typical partners in an antimatter pair, such as electrons and positrons, have electric charge and are distinguishable; neutrinos have no charge.)

    Measuring Mass

    Zeroing in on the half-life of xenon-136 – how long it would take half the xenon-136 atoms to undergo neutrinoless double-beta decay – is also necessary because the half-life is related to the neutrino’s “effective” mass: the longer the half-life, the smaller the effective mass.

    The effective mass of a neutrino is a parameter that accounts for the process of neutrino mixing (“oscillations”) taking place among the three types, or flavors, of neutrinos, called electron neutrinos, muon neutrinos and tau neutrinos. The effective mass is a particular mix of the same mass parameters that govern neutrino oscillations – a mix specific to the process of neutrinoless double-beta decay. The EXO-200 results, as reported in Nature, are consistent with an effective mass for the neutrino ranging between 190 to 450 thousandths of an electronvolt – if it is its own antiparticle. For comparison consider the electron, which weighs in at half a million electronvolts.

    If it does exist, neutrinoless double-beta decay is one of the rarest processes in the universe. “Given two xenon-136 atoms, you could wait many, many times longer than the universe has existed before one of them decays,” said Gratta.

    To get around the “many times the current age of the universe” issue, EXO-200’s tank holds 200 kilograms of xenon – enough atoms, said Gratta, to considerably improve the team’s chances of seeing a decay. Its underground location in the salt formation helps protect it from background sources, such as cosmic rays or the radioactive signatures of other naturally decaying elements, which could also trigger the detectors.

    Getting Better at Gathering Data

    Gratta said the researchers originally planned to take data for three years, but have additional upgrades in the works that could increase the instrument’s sensitivity yet again.

    However, new upgrades will need to wait until some issues at WIPP are resolved.

    “Problems at the WIPP facility have sidelined our experiment since Feb. 5 and, while we intend to continue the program, it is unclear when we’ll be able to resume,” said SLAC physicist and EXO-200 member Peter Rowson.

    When they do, he said, the second round of upgrades is expected to significantly improve performance.

    “We’ve already tested and plan to install an upgrade to the electronics,” Gratta said; this should increase the detector’s ability to find the signals of the decay – if they exist. With other planned improvements, including a plan to reduce the natural background radiation even further, he said, the EXO-200 team looks forward to substantial further improvement in the search sensitivity from an additional three years of operation.

    See the full article here.

    SLAC Campus
    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.
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  • richardmitnick 11:47 am on November 22, 2013 Permalink | Reply
    Tags: , , , Neutron Science, ,   

    From Fermilab: “Managing and moving massive data for NOvA” 


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

    Friday, Nov. 22, 2013
    Nathan Mayer, Tufts University,
    Gavin Davies, Iowa State University

    Members of the NOvA experiment, along with personnel from the Scientific Computing Division and systems administrators from participating Open Science Grid institutions, recently deployed the experiment’s large-scale C++ analysis code to run on demand on participating OSG sites. The resulting production campaign was the culmination of several months of work.

    NOvA is attempting to observe the appearance of electron neutrinos as a result of neutrino oscillations within the NuMI beam. The NOvA far detector is usually run with two main independent output-event streams, a cosmic trigger and a beam trigger, which contains the oscillated neutrino signal. The data is transferred back to Fermilab as soon as it becomes available and is cataloged and archived for permanent storage. To extract the oscillated neutrino signal from this data, it is critical to understand the cosmic-ray background in great detail. This is done through computing simulations, the focus of the computational activity on OSG.

    far detector
    NOvA Far Detector in Minnesota

    bldg
    Far Detector Building

    The deployment team faced two major obstacles that they needed to overcome: deploying a consistent version of rapidly changing software to many different OSG sites and efficiently transferring large amounts of data to these sites. To overcome the first challenge, they used the CERN Virtual Machine File System. CVMFS stores an experiment’s entire software suite, including all of the external dependencies, on a set of distribution servers. As individual worker nodes require access to software libraries, they download the needed libraries and store them in a local cache. The system downloads only the software that is needed for an individual job rather than the entire suite.

    The second challenge, efficiently transferring data to sites, was tackled by using Fermilab’s file cataloging front end, using software called dCache, to its ENSTORE mass storage system. From dCache, the sequential access via metadata (SAM) data management system retrieves the input file and then transfers the files in series to the worker nodes, which process the input file. Once the processing is completed, output files are automatically transferred back to Fermilab for cataloging and archiving. The NOvA collaboration targeted the generation of 1,000,000 events — about three times as many events as have ever been produced in the past. This was achieved by running 10,000 jobs, requiring almost 90,000 CPU hours and producing 2 terabytes of data during two weeks of operations.

    NOvA’s Andrew Norman and Fermilab’s Gabriele Garzoglio spearheaded this effort, along with collaborators from Southern Methodist University, University of Nebraska-Lincoln, University of Chicago, University of California, San Diego, University of Wisconsin – Madison and FermiCloud. The lessons learned and success of these accomplishments serve as good precursors for use of the OSG by other similar experiments, such as LBNE.

    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 10:57 am on August 13, 2013 Permalink | Reply
    Tags: , , , Neutron Science,   

    From ORNL Lab: “Neutrons’ view of hydrogen yields insight into HIV drug design” 

    ORNL-led study demonstrates relevance of neutrons in biomedical research

    August 13, 2013
    Morgan McCorkle

    “A new study from an international team led by the Department of Energy’s Oak Ridge National Laboratory is guiding drug designers toward improved pharmaceuticals to treat HIV. The scientists used neutrons and x-rays to study the interactions between HIV protease, a protein produced by the HIV virus, and an antiviral drug commonly used to block virus replication.

    atom
    An ORNL-led team used neutrons to study the interactions between HIV protease, a protein produced by the HIV virus, and an antiviral drug called amprenavir commonly used to block virus replication. The magenta mesh is the neutron scattering density map showing the exact locations of hydrogen atoms bound to oxygen atoms. The blue dashed lines represent the strongest hydrogen bonds between the drug and the enzyme. This knowledge will help researchers improve the drug’s chemistry and increase its effectiveness.No image credit.

    Using neutrons from the Institut Laue-Langevin in Grenoble, France, the researchers gained a never-before-seen view of hydrogen bonds that connect the HIV protease and the drug. Unlike x-rays, neutrons can easily detect the position of hydrogen atoms.

    ‘Knowing where hydrogen atoms are located gives researchers a much better idea about the nature and strength of the interactions,’ said lead author Andrey Kovalevsky of ORNL. ‘By applying neutron crystallography we have effectively increased the clarity of this picture, because hydrogen atoms become visible in the neutron structures. Using neutrons, we are now able to see every atom in a protein-drug complex, all the way to the smallest atom in nature.’

    The research, published in the Journal of Medicinal Chemistry, presents drug designers with a set of new potential sites for the improvement of the drug’s surface chemistry to significantly strengthen the binding, thereby increasing the effectiveness of the drugs and reducing the necessary dosages.”

    See the full article here.
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  • richardmitnick 2:34 pm on February 28, 2013 Permalink | Reply
    Tags: , Neutron Science,   

    From ORNL: “ORNL begins implementation of new californium-252 production contract” 

    Oak Ridge National Laboratory

    Feb. 28, 2013
    Bill Cabage

    The Department of Energy’s Oak Ridge National Laboratory – home of one of only two reactor facilities in the world capable of producing californium-252 (Cf-252) – has begun implementing a new six-year contract between the DOE Isotope Program and industry to make this unique and versatile radioisotope.

    The new contract follows the successful completion of a four-year Cf-252 program under an agreement with a consortium of industries that use the neutron emitting radioisotope for a number of applications that focus mostly on analysis, detection and nuclear energy.

    ‘Californium-252 serves as a unique, portable neutron source,’ said Julie Ezold, who manages ORNL’s Cf-252 production program. ‘A cross-cut of industries including coal, oil and mineral companies rely on it for critical applications, and it is used in defense and national security applications.'”

    See the full article here.

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    ORNL is managed by UT-Battelle for the Department of Energy’s Office of Science.

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  • richardmitnick 1:54 pm on February 20, 2013 Permalink | Reply
    Tags: , , , , , Neutron Science   

    From Fermilab: “NOvA data concentrator modules near completion” 


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

    Wednesday, Feb. 20, 2013
    Leah Hesla

    News on Fermilab’s NOvA experiment has largely focused on the assembly of the enormous blocks that make up the football-field-sized particle detector in Minnesota. But elsewhere in the NOvA collaboration, engineers have been diligently plugging away at a more hidden-away part of the detector, a component without which the giant device would never be able to intelligibly reveal what it sees.

    dc
    The NOvA data concentrator module collects and organizes all the particle interaction information generated inside the detector. Engineers are completing the design and testing of the system. Photo: Reidar Hahn

    This crucial component is the circuitry and computer code that make up NOvA’s data concentrator modules, or DCMs. Now, after several years of design work and many months of testing and prototyping, engineers are completing the system. Nearly all that remains is for the modules to be installed onto the NOvA detector blocks as they, too, are installed.

    ‘Many people worked hard to develop a DCM system we expect to run very smoothly,’ said Fermilab’s Ron Rechenmacher, who led one of the DCM hardware-software integration efforts.

    The NOvA DCM is a key component of the detector’s data acquisition system, which is responsible for collecting and organizing all the particle interaction information generated inside NOvA’s two detectors. When a particle interacts inside the detector, its energy is transmitted through the detector’s fiber optic system as light signals, which get converted to digital signals by electronics boards, travel through the DCMs and eventually make their way to the larger data acquisition system. The electronics boards and DCM together convert the signals into language that experimenters can later analyze.

    NOvA’s DCM system comprises about 180 modules. Each of these custom modules, about the size of a briefcase, attaches to the detector. One hundred sixty-eight of them are assigned to NOvA’s far detector in Minnesota, and a dozen or so belong to the smaller near detector at Fermilab.”

    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 10:55 am on February 15, 2013 Permalink | Reply
    Tags: , , , Neutron Science,   

    From Fermilab- “Frontier Science Result: MiniBooNE Nudging the community towards measuring where all the antimatter went” 


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

    Friday, Feb. 15, 2013
    Joe Grange

    jl
    Joe Grange, University of Florida, performed the analysis for this MiniBooNE result.

    Like many of the processes we study at Fermilab, neutrino interactions probe fundamental properties of the universe. The focus of the MiniBooNE experiment has been to identify whether muon-type neutrinos spontaneously change into electron-type neutrinos in one of the neutrino beams created at the lab, possibly implying an extra neutrino state. However, recent work on the interactions of the muon-type neutrinos themselves has proven compelling as well, and this new result provides a first look at a specific muon antineutrino interaction.

    graph
    This fundamental cross section shows the probability for a muon antineutrino to interact with a nucleon and produce a positively charged muon and any number of nucleons. For the first time, the MiniBooNE experiment has been able to split this measurement into a function of muon energy and scattering angle. By directly measuring the muon kinematics, these new data offer unprecedented insight into the behavior of the muon in antineutrino CCQE [(traditionally called a charged current quasi-elastic, or CCQE, interaction)]interactions. No image credit

    In 2010, MiniBooNE released the first measurement of the cross section for muon-type neutrinos to elastically interact with a neutron to produce a muon and nucleons (traditionally called a charged current quasi-elastic, or CCQE, interaction) as a function of both muon energy and production angle relative to the incoming neutrino.

    The new data presented here provides the world’s first look at how muon antineutrinos behave in similar reactions. Like the neutrino-based measurement of 2010, this antineutrino result also contributes to our knowledge of nuclear physics processes. Together, these measurements significantly advance the preparedness of the community to search for new physics with neutrinos.”

    See the full article here. Follow the links for added information.

    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 12:01 pm on August 16, 2012 Permalink | Reply
    Tags: , , , , Neutron Science   

    From Fermilab Today: “Special Result of the Week – The search for new physics in Fermilab’s Booster neutrino beamline” 


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

    Thursday, Aug. 16, 2012
    Warren Huelsnitz

    The conventional picture of neutrinos involves three types: the electron neutrino (and antineutrino), the muon (anti)neutrino, and the tau (anti)neutrino. As they zip through matter or space, the three types, or flavors, continually morph into each other in a phenomenon called neutrino oscillation. On the rare occasions that they interact with matter, they do so through the weak nuclear force.

    graph
    In this joint MiniBooNE-SciBooNE analysis, the experiments have excluded the area to the right of the 90 percent confidence level limit curve (blue) as a region where muon antineutrino disappearance may be occurring. This significantly narrows down the oscillation region for sterile neutrinos.

    But there is growing evidence for short-baseline neutrino anomalies that cannot be explained by the conventional picture. These anomalies include both an excess of events observed by Los Alamos National Laboratory’s Liquid Scintillator Neutrino Detector experiment and Fermilab’s MiniBooNE experiment and a deficit of events observed by reactor and radioactive-source experiments. If these anomalies are in fact due to neutrinos changing from one flavor to another, then there must be one or more new kinds of neutrinos. These additional neutrinos may be what are called ‘sterile neutrinos’ because they do not interact by the weak nuclear force.

    The MiniBooNE experiment, operating in Fermilab’s Booster neutrino beamline since 2002, can search for the appearance of electron (anti)neutrinos or the disappearance of muon (anti)neutrinos. MiniBooNE has reported on appearance signals consistent with the Los Alamos LSND experiment. If electron (anti)neutrino appearance in the Booster neutrino beamline is due to oscillations, with a sterile neutrino acting as an intermediary between electron flavor and muon flavor (anti)neutrinos, then observation of the muon (anti)neutrino disappearance would be a smoking-gun signal for the presence of these sterile neutrinos. With some back-of-the-envelope calculations, it can be shown that on the order of 10 percent of the muon (anti)neutrinos, at certain energies, should be transitioning to sterile neutrinos and hence be unobservable.”

    Interested? Read on here.

    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 10:34 am on July 13, 2012 Permalink | Reply
    Tags: , , , , Neutron Science, ,   

    From Fermilab Today: “Physics in a Nutshell – Coping with high luminosity” 


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

    Friday, July 13, 2012
    Don Lincoln

    For some sorts of physics, the probability of an interaction is really, really small. This is the case with neutrino physics. Every two seconds, about ten trillion protons are extracted from the Fermilab accelerator and blasted into a target, making neutrinos. These neutrinos travel through the Earth to a distant detector, in which scientists observe a few neutrino interactions. To give a sense of scale, after about 1021 protons, the MINOS experiment has observed about 3,000 neutrinos in the far detector. In rough terms, that works out to about one observed neutrino interaction every eight to 24 hours. That’s pretty straightforward to keep track of. Increasing the beam’s intensity by a factor of ten means the time between neutrino interactions shrinks to something like an hour or so – still very easy to track. The slow rate doesn’t tax the capabilities of the equipment at all. Thus, more intensity just shortens the length of time it takes to record enough data.

    image
    This figure is a side view of the center of CERN’s CMS detector immediately after two beams passed through one another. Our best estimate is that 50 independent collisions occurred simultaneously. This figure gives an idea of the challenges that come with increasing the luminosity of our beams. No image credit.

    However, not all experiments have such a low interaction probability. In the LHC, collisions are far more frantic. At design luminosity we’re talking about 20 interactions every time the beams cross. Since the beams will cross, or collide, about 40 million times a second when the machine is operating in its final configuration, we’re talking about nearly a billion interactions per second. At that rate, the detector and electronics are barely coping. Scientists have to come up with some interesting tricks.
    The first trick is called a trigger…”

    See the full article here.

    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.

     
  • richardmitnick 3:03 pm on June 22, 2012 Permalink | Reply
    Tags: , , CERN n_TOF, , Neutron Science, ,   

    From CERN: “CERN’s Neutrons Fly Higher” 

    The construction of a second experimental area for n_TOF – CERN’s neutron source – has just been approved by the CERN Council. The new facility will provide the scientific community with a higher neutron flux, which translates into a higher sensitivity for the experiments. The new neutron beam line will open the way to a wider variety of research fields including nuclear energy applications, nuclear astrophysics, basic nuclear physics, dosimetry and radiation damage.

    ntof
    The 4π calorimeter inside the n_TOF experimental area. Image courtesy of the n_TOF Collaboration

    The project involves building a vertical flight path roughly 20 m above the current neutron target and a new experimental hall – Experimental Area 2 (EAR-2) – in the current Building 559. EAR-2 will be located on top of the neutron production target and partially on top of the ISR building (see the image below of a model of the facility). ‘The hall will be housed in a bunker, which will be connected with the n_TOF underground facilities via a duct 60 cm in diameter,’ explains Enrico Chiaveri, spokesperson for the n_TOF collaboration. ‘Due to the expected weight of the bunker, support pillars roughly 12 m high will have to be built with their feet located on the concrete structure of the n_TOF tunnel.’”

    See the full article here.

    Meet CERN in a variety of places:

    Cern Courier

    ATLAS

    i2

    ALICE

    CMS

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    LHCb
    i4

    LHC

    Quantum Diaries

     
  • richardmitnick 9:51 am on June 8, 2012 Permalink | Reply
    Tags: , , , , , Neutron Science, ,   

    From Fermilab Today: “MINOS reports new measurement of neutrino velocity “ 

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

    Friday, June 8, 2012
    Leah Hesla

    Scientists from Fermilab’s MINOS experiment are reporting a new measurement of the velocity of the neutrino.

    minos
    Scientists at the MINOS experiment measure neutrinos that travel 450 miles through the earth. They travel first through a detector at Fermilab and then through a second detector, pictured here, in a mine in Soudan, Minn. Photo: Fermilab

    The neutrino, which is the lightest known particle, is expected to move so close to the speed of light that experiments use it as a point of comparison and expect any deviations to be extremely small.

    The new MINOS measurement, presented yesterday by Fermilab’s Phil Adamson at the XXV International Conference on Neutrino Physics and Astrophysics in Kyoto, Japan (Neutrino 2012), uses seven years of data taken by the MINOS experiment. This extends an earlier published study by MINOS using a factor of 8.5 more data.

    Most importantly, the new MINOS study significantly reduces the systematic errors of its earlier work with detailed measurements of the behavior of the experiment’s GPS timing system, improved understanding of the delays of electronic components at every stage of the MINOS detectors and the use of upgraded timing equipment, designed and implemented with the assistance of the National Institute of Science and Technology and the United States Naval Observatory.”

    See the full article here.


    Wilson Hall

     
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