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  • richardmitnick 4:33 pm on July 1, 2021 Permalink | Reply
    Tags: "Department of Energy Awards 22 Million Node-Hours of Computing Time to Support Cutting-Edge Research", Advanced Scientific Computing Research (ASCR) Leadership Computing Challenge (ALCC) program, , , , , , , , , , U.S. Department of Energy Office of Science   

    From U.S. Department of Energy Office of Science: “Department of Energy Awards 22 Million Node-Hours of Computing Time to Support Cutting-Edge Research” 

    DOE Main

    From U.S. Department of Energy Office of Science

    Department of Energy Awards 22 Million Node-Hours of Computing Time to Support Cutting-Edge Research
    The U.S. Department of Energy’s (DOE) Office of Science today announced that 22 million node-hours for 41 scientific projects under the Advanced Scientific Computing Research (ASCR) Leadership Computing Challenge (ALCC) program. The projects, with applications ranging from nuclear forensics to advanced energy systems to climate change, will use DOE supercomputers to uncover unique insights about scientific problems that would otherwise be impossible to solve using other experimental approaches.

    Selected projects will receive computational time, also known as node-hours, on one or multiple DOE supercomputers to conduct research that would take years to complete on a standard desktop computer. A node-hour is the usage of one node (or computing unit) on a supercomputer for one hour. A project allocated 1,000,000 node-hours could run a simulation on 1,000 compute nodes for 1,000 hours – vastly reducing the total amount of time required to complete the simulation. These three supercomputers – The Oak Ridge Leadership Computing Facility’s “Summit” system at DOE’s Oak Ridge National Laboratory (US), The Argonne Leadership Computing Facility’s “Theta” system at DOE’s Argonne National Laboratory (US), and the DOE’s National Energy Research Scientific Computing Center’s “Cori” system at DOE’s Lawrence Berkeley National Laboratory (US) – are among the fastest computers in the nation. Oak Ridge National Laboratory’s “Summit” currently performs as the second fastest computer in the world.

    “The Department of Energy is committed to providing the advanced scientific tools needed to move U.S. science forward. Supercomputers allow us to explore scientific problems in ways we haven’t been able to in the past – modeling dangerous, large, or costly experiments, safely and quickly,” said Barb Helland, DOE Associate Director for DOE Office of Science Advanced Scientific Computing Research (US). “The ALCC awards are just one example of how the DOE’s investments in supercomputing benefit researchers all across our nation to advance our nation’s scientific competitiveness, accelerate clean energy options, and to understand and mitigate the impacts of climate change.”

    The ASCR Leadership Computing Challenge (ALCC) program supports efforts to broaden community access to DOE’s computing facilities. ALCC focuses on high-risk, high-payoff simulations in areas directly related to the DOE mission and seeks to broaden the community of researchers who use DOE’s advanced computing resources. The 2021 awardees are awarded compute time at DOE’s high-performance computing facilities at Oak Ridge National Laboratory in Tennessee, Argonne National Laboratory in Illinois, and the National Energy Research Scientific Computing Center (US) at Lawrence Berkeley National Laboratory in California. Of the 41 projects, 3 are from industry, 19 are led by universities and 19 are led by national laboratories.
    The projects cover a variety of topics, including:
    • Climate change research, including improving climate models, studying the effects of turbulence in oceans, characterizing the impact of low-level jets on wind farms, improving the simulation of biochemical processes, and simulating clouds on a global scale.
    • Energy research, including AI and deep learning prediction for fusion energy systems, modeling materials for energy storage, studying wind turbine mechanics, and research into the properties of lithium battery electrolytes.
    • Medical research, such as deep learning for medical natural language processing, modeling cancer screening strategies, and modeling cancer initiation pathways.
    Learn more about the 2021 ALCC awardees by visiting the ASCR website. The ALCC application period will re-open for the 2022-23 allocation cycle in Fall 2021.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition
    The mission of the Energy Department is to ensure America’s security and prosperity by addressing its energy, environmental and nuclear challenges through transformative science and technology solutions.

    Science Programs Organization

    The Office of Science manages its research portfolio through six program offices:

    Advanced Scientific Computing Research
    Basic Energy Sciences
    Biological and Environmental Research
    Fusion Energy Sciences
    High Energy Physics
    Nuclear Physics

    The Science Programs organization also includes the following offices:

    The Department of Energy’s Small Business Innovation Research and Small Business Technology Transfer Programs, which the Office of Science manages for the Department;
    The Workforce Development for Teachers and Students program sponsors programs helping develop the next generation of scientists and engineers to support the DOE mission, administer programs, and conduct research; and
    The Office of Project Assessment provides independent advice to the SC leadership regarding those activities essential to constructing and operating major research facilities.

     
  • richardmitnick 12:10 am on July 1, 2021 Permalink | Reply
    Tags: "Basic to Breakthrough- How Exploring the Building Blocks of the Universe Sets the Foundation for Innovation", , , , , , , , U.S. Department of Energy Office of Science,   

    From U.S. Department of Energy Office of Science: “Basic to Breakthrough- How Exploring the Building Blocks of the Universe Sets the Foundation for Innovation” 

    DOE Main

    From U.S. Department of Energy Office of Science

    June 28, 2021

    1
    The Large Hadron Collider (LHC) at European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN] is one of the premier particle physics research facilities.

    U.S. researchers were instrumental in building technology in the facility as well as discovering the Higgs boson there. Image courtesy of CERN

    What are the basic building blocks of our cosmos, and how do they interact? What happens at the smallest levels, and what hidden potential lies therein? How did our universe evolve, and what may the future hold? Particle physics research seeks that knowledge.

    Scientists supported by the U.S. Department of Energy tackle these fundamental mysteries at universities and national labs across the country. They build state-of-the-art experiments that yield incredible discoveries and achievements. Along the way, they create new technologies, applications, and a highly trained workforce.

    In the past, these technologies have found uses in areas as diverse as consumer electronics and medicine. When J. J. Thomson discovered the electron in 1897, few could imagine that one day life might largely revolve around devices built around it. When accelerator magnets were engineered to power the discovery of new particles, few foresaw their spinoff to new life-saving roles in MRI machines and cancer treatment. While today’s basic research delves into the fundamentals of our cosmos, it too may reveal knowledge that we will build on in tomorrow’s breakthroughs.

    Perhaps the most well-known physics discovery of the past decade was that of the Higgs boson. It’s a long sought after particle that helps give rise to much of the mass in the universe. Hundreds of scientists at DOE labs and universities were part of the international teams that co-discovered the particle in 2012. Scientists have since learned much about how the Higgs boson lives, decays, and interacts with other particles. U.S. researchers were also instrumental in building the accelerator technology that made the intense high-energy beams of particles. They’re now making upgrades to the Large Hadron Collider’s particle accelerators and detectors, building innovative equipment and setting world records along the way.

    In the U.S., particle physicists have also built on and expanded prior knowledge. Earlier this year, the Muon g-2 experiment at Fermilab provided further proof of an anomaly discovered 20 years ago at Brookhaven Lab. Researchers found that muons (the heavier cousins of electrons) behave in a way that scientists’ best theory does not predict—possibly because of new subatomic particles or forces at work.

    Another class of particles known as neutrinos also display odd properties that hint at new physics. Researchers want to figure out whether these particles were key players in how our universe evolved, particularly if they’re the reason matter exists at all. The recent operation at CERN of a house-sized neutrino detector called ProtoDUNE successfully demonstrated the novel technology needed to help answer that question.

    Together with our international partners, we will use it to build the Deep Underground Neutrino Experiment here in the U.S. It’s a project made possible by the world’s most intense high-energy neutrino beam.



    Researchers also gather more clues on the nature of dark matter, which makes up most of the mass in the universe. Using a gigantic, ultrasensitive camera developed at our national labs, the Dark Energy Survey produced the largest dark matter maps of the cosmos.

    _____________________________________________________________________________________
    Dark Energy Survey

    The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. DES began searching the Southern skies on August 31, 2013.

    According to Einstein’s theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or General Relativity must be replaced by a new theory of gravity on cosmic scales.

    DES is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 400 scientists from over 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, Switzerland, and Australia are working on the project. The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

    Over six years (2013-2019), the DES collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.
    _____________________________________________________________________________________

    A suite of current and upcoming experiments – including ADMX, DESI, the Vera Rubin Observatory, LZ and SuperCDMS – is poised to reveal dark matter’s secrets through direct detection and further mapping of matter.

    _____________________________________________________________________________________

    LBNL/DESI Spectroscope instrument on the 4 meter Mayall telescope, at Kitt Peak, Arizona, USA, Altitude 2,120 m (6,960 ft)

    LBNL/DESI spectroscopic instrument on the Mayall 4-meter telescope at Kitt Peak National Observatory starting in 2018


    _____________________________________________________________________________________

    These maps of the celestial distribution of matter also help us understand the properties of the mysterious dark energy responsible for the accelerated expansion of the universe.

    Our national labs also use their expertise in the quantum world to make important strides in quantum information science. The launch of the National Quantum Initiative has emphasized the importance of QIS to the nation’s cybersecurity and economic competitiveness. Scientists, engineers, and technicians at five new national quantum centers are working to build everything from quantum sensors to computers. They implement particle accelerator technologies and new computing algorithms while training a quantum workforce. A crucial step on the way to a viable quantum internet, DOE-funded researchers even made the first demonstration of sustained high-fidelity quantum teleportation.

    While used in particle physics to smash particles together, accelerator technology also has applications in medicine, energy, national security, and materials science. In medicine alone, accelerators are used in imaging devices, radiation treatment for cancer, and X-ray beams to develop more effective drugs. Investments in accelerator research improve our current facilities as well as pursue advances that could result in new technologies. For example, laser-driven plasma wake field technology may be able to make the length of an accelerator 2,000 times smaller than today’s machines. Our accelerator stewardship program helps make this technology more widely available to science and industry.

    Applications for the new knowledge gained by basic physics research are broad and transform society, yet are difficult to predict. They go hand-in-hand with answering one of our most fundamental questions: How does this universe work?

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition
    The mission of the Energy Department is to ensure America’s security and prosperity by addressing its energy, environmental and nuclear challenges through transformative science and technology solutions.

    Science Programs Organization

    The Office of Science manages its research portfolio through six program offices:

    Advanced Scientific Computing Research
    Basic Energy Sciences
    Biological and Environmental Research
    Fusion Energy Sciences
    High Energy Physics
    Nuclear Physics

    The Science Programs organization also includes the following offices:

    The Department of Energy’s Small Business Innovation Research and Small Business Technology Transfer Programs, which the Office of Science manages for the Department;
    The Workforce Development for Teachers and Students program sponsors programs helping develop the next generation of scientists and engineers to support the DOE mission, administer programs, and conduct research; and
    The Office of Project Assessment provides independent advice to the SC leadership regarding those activities essential to constructing and operating major research facilities.

     
  • richardmitnick 10:53 am on September 11, 2020 Permalink | Reply
    Tags: "Future machines to explore new frontiers in particle physics", , CERN FCC Future Circular Collider 100km-diameter successor to LHC., CERN-European Organization for Nuclear Research, FNAL Long-Baseline Neutrino Facility, FNAL new superconducting accelerator Proton Improvement Plan II (PIP-II), , , , , , , U.S. Department of Energy Office of Science   

    From U.S. Department of Energy Office of Science: “Future machines to explore new frontiers in particle physics” 

    DOE Main

    From U.S. Department of Energy Office of Science

    September 10, 2020

    Jim Siegrist
    Associate Director for High Energy Physics Office
    U.S Department of Energy
    Email: news@science.doe.gov

    Particle physics is global. Addressing the full breadth of the field’s most urgent scientific questions requires expertise from around the world. The timeline for developing a world-class international facility to explore new frontiers in the subatomic world may take decades, but it is built from a multitude of milestones marking scientific and technical advances. The U.S. Department of Energy’s (DOE’s) Office of Science is working with partners around the globe to realise the next generation of particle physics facilities and enable future discoveries.

    Studying the science of neutrinos

    Today, the foundational groundwork is underway in the U.S. to host an international facility to study the science of neutrinos. These ghostly particles rarely interact with other forms of matter and change their flavour between three known types as they travel. To enable precision study of this puzzling behaviour, the Long-Baseline Neutrino Facility (LBNF) will produce the world’s most intense beam of neutrinos at DOE’s Fermi National Accelerator Laboratory (Fermilab), in Illinois, and send them 1,300 km through the earth to the Sanford Underground Research Facility in South Dakota.

    SURF-Sanford Underground Research Facility, Lead, South Dakota, USA.

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

    A new superconducting particle accelerator at Fermilab, the Proton Improvement Plan II (PIP-II), will provide the high-intensity proton beam needed to create the neutrinos.

    FNAL new superconducting accelerator Proton Improvement Plan II (PIP-II).

    About 1,500 m below the surface of the Earth in South Dakota, the Deep Underground Neutrino Experiment (DUNE) will measure neutrinos as they arrive from Illinois as well as from natural sources, such as supernovas from our region of the Milky Way. An international collaboration of over 1,000 scientists from 33 countries is now working to develop and build the large-scale DUNE detector, using results from prototypes at the CERN Neutrino Platform to refine their design and affirm the technology.

    International partnerships will play a crucial role in the successful realisation of this new international neutrino facility. The DOE Office of Science is working to strengthen existing collaborative partnerships in High Energy Physics and build new ones with global partners in order to bring together the necessary scientific talent and technical expertise. Formal agreements are currently in place with the European Organization for Nuclear Research (CERN) as well as the governments of India, Italy, and the United Kingdom, to contribute to different areas of this mega-scale neutrino endeavour.

    Discussions to expand the partnerships are now underway with several other countries across Europe, Asia, and South America. In fact, through such cooperative partnerships, the contributions for PIP-II will make this facility the first accelerator project hosted in the U.S. with significant contributions from global partners.

    Developing particle accelerator technology

    The DOE Office of Science is also developing particle accelerator technology that will help enable future particle physics facilities around the world. DOE is supporting the development of a future “Higgs factory,” an electron-positron collider with international participation that could produce many Higgs bosons to enable precision studies that complement those at the Large Hadron Collider (LHC) at CERN.

    To realise this vision, DOE supports the R&D of accelerator and detector technologies to enable Japan to move forward with the International Linear Collider (ILC).


    ILC schematic, being planned for the Kitakami highland, in the Iwate prefecture of northern Japan.

    Over the past year, DOE has also worked with the U.S. Department of State, The White House Office of Science & Technology Policy, and the National Security Council to make a concerted effort to support a Japanese initiative to move forward with the proposed ILC “Pre-Laboratory” phase of the project.

    Our scientists are developing improvements to the superconducting technology that will increase accelerator cavity efficiency and reduce the cost of construction and subsequent operations.

    FNAL A superconducting radiofrequency cavity responsible for accelerating particles at the new PIP-II accelerator.

    In June, the CERN Council unanimously adopted the resolution updating the 2020 European Strategy for Particle Physics. As recently pointed out by the CERN Director-General, the strategy is visionary and ambitious while remaining realistic and prudent, emphasising many exciting future initiatives in particle physics that can be achieved in collaboration with global partners, including the DOE. As one of its high priorities, the European strategy reaffirms the successful completion of the high-luminosity upgrades of the LHC accelerator and the LHC experimental ATLAS and CMS detectors. To enable this next era of the LHC program, the DOE Office of Science is contributing key magnets and cavity components to the accelerator upgrade, including high-field niobium-tin-based superconducting magnets developed in the United States, as well as state-of-the-art detector elements for the ATLAS and CMS detector upgrades.

    The future: New frontiers in particle physics

    Looking to the farther future towards the next facility after the LHC, studies are underway for a Future Circular Collider (FCC), the next-generation complex that could reach particle collision energies over seven times that of the LHC. The development of such a facility is one of the key focal points of the 2020 update of the European strategy.

    CERN FCC Future Circular Collider details of proposed 100km-diameter successor to LHC.

    Earlier this year, the DOE Office of Science partnered with CERN and national laboratories across Europe on a FCC Innovation Study as part of a European Commission Horizon 2020 Design Study initiative that would investigate the technical design for a 100 km circumference collider in the French-Swiss border, one that could also leverage the existing infrastructure at CERN. The study would enable scientists and engineers to optimise the particle collider design and plan investigations into a suitable civil engineering project while also allowing all global partners to integrate into the study’s network and user community.

    Moreover, DOE and CERN have recently begun discussions to expand DOE’s cooperation into CERN’s proposed future collider and is looking forward to working with CERN and other global partners to envision the technology that could achieve a FCC. Overall, facilities such as the LHC, FCC and LBNF/DUNE/PIP-II across the frontiers of science and technology promise to enable our quest to explore and achieve groundbreaking discoveries.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The mission of the Energy Department is to ensure America’s security and prosperity by addressing its energy, environmental and nuclear challenges through transformative science and technology solutions.

    Science Programs Organization

    The Office of Science manages its research portfolio through six program offices:

    Advanced Scientific Computing Research
    Basic Energy Sciences
    Biological and Environmental Research
    Fusion Energy Sciences
    High Energy Physics
    Nuclear Physics

    The Science Programs organization also includes the following offices:

    The Department of Energy’s Small Business Innovation Research and Small Business Technology Transfer Programs, which the Office of Science manages for the Department;
    The Workforce Development for Teachers and Students program sponsors programs helping develop the next generation of scientists and engineers to support the DOE mission, administer programs, and conduct research; and
    The Office of Project Assessment provides independent advice to the SC leadership regarding those activities essential to constructing and operating major research facilities.

     
  • richardmitnick 2:48 pm on September 7, 2020 Permalink | Reply
    Tags: "The Mystery of the Neutron Lifetime", , , How long the neutron takes to fall apart presents a bit of a mystery., Nine seconds-just long enough to confound nuclear physicists studying the lifetime of the neutron., , , , The neutron lifetime may also provide insight into what happened just moments after the Big Bang., The neutron the simplest particle that is radioactive which means that it regularly breaks down into other particles., U.S. Department of Energy Office of Science   

    From U.S. Department of Energy Office of Science: “The Mystery of the Neutron Lifetime” 

    DOE Main

    From U.S. Department of Energy Office of Science

    1
    From left, ORNL staff Matthew Frost and Leah Broussard work at the Magnetism Reflectometer at the Spallation Neutron Source, used for a search for mirror neutrons. Image courtesy of Genevieve Martin /Oak Ridge National Laboratory, U.S. Dept. of Energy.

    ORNL Spallation Neutron Source.


    ORNL Spallation Neutron Source.

    Nine seconds. An eternity in some scientific experiments; an unimaginably small amount in the grand scheme of the universe. And just long enough to confound nuclear physicists studying the lifetime of the neutron.

    The neutron is one of the building blocks of matter, the neutral counterpart to the positive proton. Like many other subatomic particles, the neutron doesn’t last long outside of the nucleus. Over the course of about 15 minutes, it breaks apart into a proton, an electron, and a tiny particle called an anti-neutrino.

    But how long the neutron takes to fall apart presents a bit of a mystery. One method measures it as 887.7 seconds, plus or minus 2.2 seconds. Another method measures it as 878.5 seconds, plus or minus 0.8 second. At first, this difference seemed to be a matter of measurement sensitivity. It may be just that. But as scientists continue to perform a series of ever-more-precise experiments to evaluate possible issues, the discrepancy remains.

    This persistence leads to the possibility that the difference is pointing to some type of unknown physics. It could be revealing an unknown process in neutron decay. Or it could be pointing to science beyond the Standard Model scientists currently use to explain all of particle physics.

    Standard Model of Particle Physics, Quantum Diaries.

    There are a number of phenomena that the Standard Model doesn’t fully explain and this difference could point the way towards answering those questions.

    To unravel this strange disparity, the Department of Energy’s (DOE) Office of Science is working with other federal agencies, national laboratories, and universities to nail down the duration of the neutron lifetime.

    A Fundamental Quantity

    Nuclear physicists first started studying the neutron lifetime because of its essential role in physics. “There are some fundamental quantities in nature that seem to be always important,” said Geoff Greene, University of Tennessee professor and physicist at DOE’s Oak Ridge National Laboratory. He’s been researching the neutron lifetime for much of his lifetime – about 40 years. “Theories come and go, but the neutron lifetime seems to remain a central parameter in a variety of things.”

    The neutron is a useful guide to understanding other particles. It’s the simplest particle that is radioactive, which means that it regularly breaks down into other particles. As such, it provides a lot of insight into the weak force, the force that determines if neutrons turn into protons or not. Often, this process releases energy and causes the nuclei to break apart. The interactions of the weak force also play an important role in nuclear fusion, where two protons combine.

    The neutron lifetime may also provide insight into what happened just moments after the Big Bang. In the few seconds after protons and neutrons formed but before they joined together into elements, there was a precise bit of timing. The universe was cooling rapidly. At a certain point, it got cool enough that protons and neutrons almost instantaneously joined to form helium and hydrogen. If neutrons decayed a little faster or slower into protons, it would have vast effects on that process. There would be a very different balance of elements in the universe; it’s likely that life wouldn’t exist.

    “It’s one of those fortuitous accidents of nature that we have chemical elements at all,” said Greene.

    Scientists would like to have a solid number for the neutron lifetime to plug into these equations. They need the uncertainty of the lifetime down to less than a second. But getting this certainty is more difficult than it initially seemed. “The neutron lifetime is one of the least well-known fundamental parameters in the Standard Model,” said Zhaowen Tang, a physicist at DOE’s Los Alamos National Laboratory (LANL).

    Individual experiments have been able to reach this level of precision. But the incongruity between different types of experiments is preventing scientists from nailing down a specific number.

    Discovering a Discrepancy

    Finding out there was a difference at all arose from physicists’ desire to be comprehensive. Using two or more methods to measure the same quantity is the best way to guarantee an accurate measurement. But scientists can’t put timers on neutrons to see how fast they fall apart. Instead, they find ways to measure neutrons before and after they decay to calculate the lifetime.

    Beam experiments use machines that create streams of neutrons. Scientists measure the number of neutrons in a specific volume of the beam. They then send the stream through a magnetic field and into a particle trap formed by an electric and magnetic field. The neutrons decay in the trap, where the scientists measure the number of protons left in the end.

    “The beam experiment is a really hard way to do a precision measurement,” said Shannon Hoogerheide, a physicist at the National Institute of Standards and Technology (NIST), who has collaborated with DOE scientists. “The beam measurement requires not one, but two absolute measurements.”

    In contrast, bottle experiments trap ultra-cold neutrons in a container. Ultra-cold neutrons move much slower than regular ones – a few meters per second compared to the 10 million meters per second from fission reactions. Scientists measure how many neutrons are in the container at the beginning and then again after a certain period of time. By examining the difference, they can calculate how fast the neutrons decayed.

    “The bottle experiment measures the survivors, the beam experiment measures the dead,” said Greene. “The bottle experiment sounds easy but actually is very hard. On the other hand, the beam experiment sounds hard and is hard.”

    A beam experiment at NIST in 2005 (with support from DOE) and a bottle experiment in France not long after first revealed the difference in measurement. Since then, experiments have tried to reduce the space between the two by minimizing as many uncertainties as possible.

    Greene and his collaborators took new measurements in 2013 at NIST that helped them recalculate the 2005 beam experiment even more accurately. By that point, scientists had completed five bottle and two beam experiments. Greene was convinced that previous beam experiments had missed one of the biggest sources of uncertainty – precisely counting the number of neutrons in the beam. They improved their measurement of this variable to make it five times more accurate. But eight years of hard work left them with almost the exact same gap in results.

    Physicists working on bottle experiments faced their own struggles. One of the biggest challenges was to keep the neutrons from getting lost from interactions with the material the container is made of. A leak changes the number of neutrons at the end and throws off the lifetime calculation.

    To solve this problem, the most recent bottle experiment at LANL (which was supported by the Office of Science) eliminated physical walls. Instead, the nuclear physicists used magnetic fields and gravity to hold the neutrons in place. “I was in the camp of, if we do that, we might get a neutron to live longer and agree with the beam lifetime,” said Chen-Yu Liu, an Indiana University professor who led the experiment. “That was my personal bias.”

    But the difference remained. “That was a big shock to me,” she said, describing the result published in 2018. The odds of that difference happening from random chance are less than 1 in 10,000. But it could still be caused by a flaw in the experiments.

    Hunting Down the Root Cause

    Scientists face two types of uncertainties or errors in experiments: statistical or systematic. Statistical errors come from not having enough data to draw solid conclusions. If you can get more data, you can reliably lower those errors. Systematic errors are fundamental uncertainties with the experiment. Many times, they’re far from obvious. The two types of neuron lifetime experiments have vastly different potential systematic errors. The experiments would be a great check on each other if the results matched. But it makes it devilishly hard to figure out why they don’t.

    “The hardest thing about measuring the neutron lifetime is that it’s both too short and too long,” said Hoogerheide. “It turns out 15 minutes is a really awkward time to measure in physics.”

    So nuclear scientists are continuing work to collect more data and minimize systematic errors.

    “One of the things that I find most fun about my field is the exquisite attention to detail required and how deeply you have to understand every aspect of your experiment in order to make a robust measurement,” said Leah Broussard, a nuclear physicist at ORNL.

    At NIST, Hoogerheide, Greene, and others are running a new beam experiment [NIST-Neutron Lifetime Measurement Using a Cold Neutron Beam] that walks through each possible issue in as comprehensive a way as possible. Unfortunately, each tweak affects the others, so it’s two steps forward, one step back.

    Other efforts are looking into new ways to measure the neutron lifetime. Researchers from Johns Hopkins University and the U.K.’s Durham University supported by DOE figured out how to use data from NASA to measure the neutron lifetime [Physical Review Research]. Based on neutrons coming off of Venus and Mercury, they calculated a lifetime of 780 seconds with an uncertainty of 130 seconds. But because the data collection wasn’t designed for this purpose, the uncertainty is too high to resolve the lifetime difference. At LANL, Tang is setting up an experiment that’s a cross between the bottle and beam experiments. Instead of measuring protons at the end, it will measure electrons.

    Exotic Possibilities Await

    There’s also the possibility that the difference is revealing a gap in our knowledge of this fundamental particle.

    “We cannot leave any stones unturned,” said Tang. “There are so many examples of people who have seen something, just chucked something to a mistake, not worked on it hard enough, and someone else did and they got the Nobel Prize.”

    One theory is that the neutron is breaking down in a way that scientists simply aren’t aware of. It may break down into different particles than the familiar proton, electron, and anti-neutrino combination. If it does, that would explain why neutrons are disappearing in the bottle experiments but the corresponding number of protons aren’t showing up in the beam experiments.

    Other ideas are even more radical. Some theorists proposed that neutrons are breaking up into gamma rays and mysterious dark matter. Dark matter makes up 75 percent of the matter in the universe, yet as far as we know only interacts with regular matter via gravity. To test this theory, a group of scientists at LANL did a version of the bottle experiment where they measured both neutrons and gamma rays [Search for the Neutron Decay n→ X+γ where X is a dark matter particle]. But the proposed gamma rays didn’t materialize, leaving scientists with no evidence for dark matter from neutrons.

    Mirror matter is another possible concept that sounds like science-fiction. In theory, the “missing” neutrons could be turning into mirror neutrons, perfect copies that exist in an opposite universe. Having evolved in a different way from our universe, this mirror universe would be much colder and dominated by helium. While some nuclear scientists such as Greene think that this is “implausible,” others are interested in testing it just in case.

    “It’s relatively unexplored territory. It’s very compelling for me because I’ve got a great source of neutrons in my backyard,” said Broussard, referring to the Spallation Neutron Source and High Flux Isotope Reactor, both DOE Office of Science user facilities at ORNL.

    To test this theory, Broussard is analyzing data from an experiment that mimics the beam lifetime experiments [EPJ Web Conferences], but adjusted to catch a sign of the neutron’s potential invisible partner. By shooting a neutron beam through a specific magnetic field and then stopping it with a material that halts normal neutrons, she and her colleagues should be able to detect whether or not mirror neutrons exist.

    Whatever results this experiment delivers, the work to understand the neutron lifetime will continue. “It’s very telling that there are so many attempts to precisely measure the neutron lifetime. That tells you the emotional reaction of scientists to a discrepancy in the field – ‘I want to explore this!’” said Broussard. “Every scientist is motivated by the desire to learn, the desire to understand.”

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The mission of the Energy Department is to ensure America’s security and prosperity by addressing its energy, environmental and nuclear challenges through transformative science and technology solutions.

    Science Programs Organization

    The Office of Science manages its research portfolio through six program offices:

    Advanced Scientific Computing Research
    Basic Energy Sciences
    Biological and Environmental Research
    Fusion Energy Sciences
    High Energy Physics
    Nuclear Physics

    The Science Programs organization also includes the following offices:

    The Department of Energy’s Small Business Innovation Research and Small Business Technology Transfer Programs, which the Office of Science manages for the Department;
    The Workforce Development for Teachers and Students program sponsors programs helping develop the next generation of scientists and engineers to support the DOE mission, administer programs, and conduct research; and
    The Office of Project Assessment provides independent advice to the SC leadership regarding those activities essential to constructing and operating major research facilities.

     
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