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  • richardmitnick 10:45 am on January 22, 2019 Permalink | Reply
    Tags: , CERN Compact Linear Collider, , China-Circular Electron Positron Collider, Future colliders, , , International Linear Collider in northern Japan, , Physics,   

    From Science News: “Physicists aim to outdo the LHC with this wish list of particle colliders” 

    From Science News

    THIS HAS BECOME A HOT TOPIC AD THERE WILL BE MANY IMPORTANT ARTICLES BASED UPON NEEDS AND COSTS

    January 22, 2019
    Emily Conover

    CERN Future Circular Collider artist’s rendering

    If built, the accelerators could pump out oodles of Higgs bosons.

    If particle physicists get their way, new accelerators could one day scrutinize the most tantalizing subatomic particle in physics — the Higgs boson.

    CERN CMS Higgs Event

    CERN ATLAS Higgs Event

    Six years after the particle’s discovery at the Large Hadron Collider, scientists are planning enormous new machines that would stretch for tens of kilometers across Europe, Japan or China.

    The 2012 discovery of the subatomic particle, which reveals the origins of mass, put the finishing touch on the standard model, the overarching theory of particle physics (SN: 7/28/12, p. 5).

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

    And it was a landmark achievement for the LHC, currently the world’s biggest accelerator.

    LHC

    CERN map


    CERN LHC Tunnel

    CERN LHC particles

    Now, physicists want to delve further into the mysteries of the Higgs boson in the hope that it could be key to solving lingering puzzles of particle physics. “The Higgs is a very special particle,” says physicist Yifang Wang, director of the Institute of High Energy Physics in Beijing. “We believe the Higgs is the window to the future.”

    But the LHC — which consists of a ring 27 kilometers in circumference, inside which protons are accelerated to nearly the speed of light and smashed together a billion times a second — can take scientists only so far. That accelerator was great for discovering the Higgs, but not ideal for studying it in detail.

    So particle physicists are clamoring for a new particle collider, specifically designed to crank out oodles of Higgs bosons. Several blueprints for powerful new machines have been put forth, and researchers are hopeful these “Higgs factories” could help reveal solutions to glaring weak spots in the standard model.

    “The standard model is not a complete theory of the universe,” says experimental particle physicist Halina Abramowicz of Tel Aviv University. For example, the theory can’t explain dark matter, an unidentified substance whose mass is necessary to account for cosmic observations such as the motions of stars in galaxies. Nor can it explain why the universe is made up of matter, while antimatter is exceedingly rare.

    Carefully scrutinizing the Higgs boson might point scientists in the direction of solutions to those puzzles, proponents of the new colliders claim. But, among scientists, the desire for new, costly accelerators is not universal, especially since it’s unclear what exactly the machines might find.

    Next in line

    Closest to inception is the International Linear Collider in northern Japan. Unlike the LHC, in which particles zip around a ring, the ILC would accelerate two beams of particles along a straight line, directly at one another over its 20-kilometer length. And instead of crashing protons together, it would collide electrons and their antimatter partners, positrons.

    But, in an ominous sign, a multidisciplinary committee of the Science Council of Japan came down against the project in a December 2018 report, urging the government to be cautious with its support and questioning whether the expected scientific achievements justified the accelerator’s cost, currently estimated at around $5 billion.

    Supporters argue that the ILC’s plan to smash together electrons and positrons, rather than protons, has some big advantages. Electrons and positrons are elementary particles, meaning they have no smaller constituents, while protons are made up of smaller particles called quarks. That means that proton collisions are messier, with more useless particle debris to sift through.

    ILC


    THIN LINE An accelerator planned for Japan, the International Linear Collider (design illustrated), would slam together electrons and positrons to better understand the Higgs boson.

    Additionally, in proton smashups, only a fraction of each proton’s energy actually goes into the collision, whereas in electron-positron colliders, particles bring the full brunt of the accelerator’s energy to bear. That means scientists can tune the energy of collisions to maximize the number of Higgs bosons produced. At the same time, the ILC would require only 250 billion electron volts to produce Higgs bosons, compared with the LHC’s 13 trillion electron volts.

    For the ILC, “the quality of the data coming out will be much higher, and there will be much more of it on the Higgs,” says particle physicist Lyn Evans of CERN in Geneva. One in every 100 ILC collisions would pump out a Higgs, whereas that happens only once in 10 billion collisions at the LHC.

    The Japanese government is expected to decide about the collider in March. If the ILC is approved, it should take about 12 years to build, Evans says. The accelerator could also be upgraded later to increase the energy it can reach.

    CERN has plans for a similar machine known as the Compact Linear Collider.

    Cern Compact Linear Collider

    It would also collide electrons and positrons, but at higher energies than the ILC. Its energy would start at 380 billion electron volts and increase to 3 trillion electron volts in a series of upgrades. But to reach those higher energies, new particle acceleration technology needs to be developed, meaning that CLIC is even further in the future than the ILC, says Evans, who leads a collaboration of researchers from both projects.

    Running in circles

    Two other planned colliders, in China and Europe, would be circular like the LHC, but would dwarf that already giant machine; both would be 100 kilometers around. That’s a circle big enough that the country of Liechtenstein could easily fit inside — twice.

    At a location yet to be determined in China, the Circular Electron Positron Collider, or CEPC, would collide electrons and positrons at 240 billion electron volts, according to a conceptual plan officially released in November and championed by Wang and the Institute of High Energy Physics.

    China Circular Electron-Positron collider depiction


    China Circular Electron Positron Collider (CEPC) map

    The accelerator could later be upgraded to collide protons at higher energies. Scientists say they could begin constructing the $5 billion to 6 billion machine by 2022 and have it ready to go by 2030.

    And at CERN, the proposed Future Circular Collider, or FCC, would likewise operate in stages, colliding electrons and positrons before moving on to protons. The ultimate goal would be to reach proton collisions with 100 trillion electron volts, more than seven times the LHC’s energy, according to a Jan. 15 report from an international group of researchers.

    FCC Future Circular Collider at CERN

    Meanwhile, scientists have shut down the LHC for two years, while they upgrade the machine to function at a slightly higher energy (SN Online: 12/3/18). Further down the line, a souped-up version known as the High-Luminosity LHC could come online in 2026 and would increase the proton collision rate by at least a factor of five (SN Online: 6/15/18).

    Portrait of the Higgs

    When the LHC was built, scientists were fairly confident they’d find the Higgs boson with it. But with the new facilities, there’s no promise of new particles. Instead, the machines will aim to catalog how strongly the Higgs interacts with other known particles; in physicist lingo, these are known as its “couplings.”

    Measurements of the Higgs’ couplings may simply confirm expectations of the standard model. But if the observations differ from expectations, the discrepancy could indirectly hint at the presence of something new, such as the particles that make up dark matter.

    Some scientists are hopeful that something unexpected might arise. That’s because the Higgs is an enigma: The particles condense into a kind of molasses-like fluid. “Why does this fluid do that? We have no clue,” says theoretical particle physicist Michael Peskin of Stanford University. That fluid pervades the universe, slowing particles down and giving them heft.

    Another puzzle is that the Higgs’ mass is a million billion times smaller than expected (SN Online: 10/22/13). Certain numbers in the standard model must be fine-tuned to extreme precision make the Higgs less hefty, a situation physicists find unnatural.

    The weirdness of the Higgs suggests other particles might be out there. Scientists previously thought they had an answer to the Higgs quandaries, via a theory called supersymmetry, which posits that each known particle has a heavier partner (SN: 10/1/16, p. 12). “Before the LHC started, there were huge expectations,” says Abramowicz: Some scientists claimed the LHC would quickly find supersymmetric particles. “Well, it didn’t happen,” she says.

    The upcoming colliders may yet find evidence of supersymmetry, or otherwise hint at new particles, but this time around, scientists aren’t making promises.

    4
    BIG SMASH In the new accelerators, collisions would produce showers of exotic particles (illustrated), including the Higgs boson, which explains how particles get mass.

    “In the past, some people have clearly oversold what the LHC was expected to deliver,” says theoretical particle physicist Juan Rojo of Vrije University Amsterdam. When it comes to any new colliders, “we should avoid making the same mistake if we want to keep our field alive for decades to come,” he says.

    Researchers around the world are now hashing out priorities, making arguments for the new colliders and other particle physics experiments. European physicists, for example, will meet in May to discuss options, working toward a document called the European Particle Physics Strategy Update, to guide research there in 2020 and beyond.

    One thing is certain: The proposed accelerators would explore unknown territory, with unpredictable results. The unanswered questions surrounding the Higgs boson make it the most obvious place to look for hints of new physics, Peskin says. “It’s the place that we haven’t looked yet, so it’s really compelling.”

    Citations

    CERN. Future Circular Collider Conceptual Design Report. Published online January 15, 2018.

    European Particle Physics. Strategy Update 2018–2020.

    Linear Collider Collaboration. Executive Summary of the Science Council of Japan’s Report. LC Newsline. Published online December 21, 2018.

    The Institute of High Energy Physics of the Chinese Academy of Sciences. CEPC Conceptual Design Report Volume I – Accelerator. November 14, 2018.

    The Institute of High Energy Physics of the Chinese Academy of Sciences. CEPC Conceptual Design Report Volume II – Physics & Detector. November 14, 2018.

    See the full article here .


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  • richardmitnick 10:44 am on January 21, 2019 Permalink | Reply
    Tags: , , , , , , , Physics, ,   

    Weizmann Institute of Science via Science Alert: “We Just Got Lab-Made Evidence of Stephen Hawking’s Greatest Prediction About Black Holes” 

    Weizmann Institute of Science logo

    Weizmann Institute of Science

    via

    ScienceAlert

    Science Alert

    21 JAN 2019
    MICHELLE STARR

    Scientists may have just taken a step towards experimentally proving the existence of Hawking radiation. Using an optical fibre analogue of an event horizon – a lab-created model of black hole physics – researchers from Weizmann Institute of Science in Rehovot, Israel report that they have created stimulated Hawking radiation.

    Under general relativity, a black hole is inescapable. Once something travels beyond the event horizon into the heart of the black hole, there’s no return. So intense is the gravitational force of a black hole that not even light – the fastest thing in the Universe – can achieve escape velocity.

    Under general relativity, therefore, a black hole emits no electromagnetic radiation. But, as a young Stephen Hawking theorised in 1974, it does emit something when you add quantum mechanics to the mix.

    This theoretical electromagnetic radiation is called Hawking radiation; it resembles black body radiation, produced by the temperature of the black hole, which is inversely proportional to its mass (watch the video below to get a grasp of this neat concept).

    This radiation would mean that black holes are extremely slowly and steadily evaporating, but according to the maths, this radiation is too faint to be detectable by our current instruments.

    So, cue trying to recreate it in a lab using black hole analogues. These can be built from things that produce waves, such as fluid and sound waves in a special tank, from Bose-Einstein condensates, or from light contained in optical fibre.

    “Hawking radiation is a much more general phenomenon than originally thought,” explained physicist Ulf Leonhardt to Physics World. “It can happen whenever event horizons are made, be it in astrophysics or for light in optical materials, water waves or ultracold atoms.”

    These won’t, obviously, reproduce the gravitational effects of a black hole (a good thing for, well, us existing), but the mathematics involved is analogous to the mathematics that describe black holes under general relativity.

    This time, the team’s method of choice was an optical fibre system developed by Leonhardt some years ago.

    The optical fibre has micro-patterns on the inside, and acts as a conduit. When entering the fibre, light slows down just a tiny bit. To create an event horizon analogue, two differently coloured ultrafast pulses of laser light are sent down the fibre. The first interferes with the second, resulting in an event horizon effect, observable as changes in the refractive index of the fibre.

    The team then used an additional light on this system, which resulted in an increase in radiation with a negative frequency. In other words, ‘negative’ light was drawing energy from the ‘event horizon’ – an indication of stimulated Hawking radiation.

    While the findings were undoubtedly cool, the end goal for such research is to observe spontaneous Hawking radiation.

    Stimulated emission is exactly what it sounds like – emission that requires an external electromagnetic stimulus. Meanwhile the Hawking radiation emanating from a black hole would be of the spontaneous variety, not stimulated.

    There are other problems with stimulated Hawking radiation experiments; namely, they are rarely unambiguous, since it’s impossible to precisely recreate in the lab the conditions around an event horizon.

    With this experiment, for example, it’s difficult to be 100 percent certain that the emission wasn’t created by an amplification of normal radiation, although Leonhardt and his team are confident that their experiment did actually produce Hawking radiation.

    Either way, it’s a fascinating achievement and has landed another mystery in the team’s hands, too – they found the result was not quite as they expected.

    “Our numerical calculations predict a much stronger Hawking light than we have seen,” Leonhardt told Physics World.

    “We plan to investigate this next. But we are open to surprises and will remain our own worst critics.”

    The research has been published in the journal Physical Review Letters.

    See the full article here .

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    Weizmann Institute Campus

    The Weizmann Institute of Science is one of the world’s leading multidisciplinary research institutions. Hundreds of scientists, laboratory technicians and research students working on its lushly landscaped campus embark daily on fascinating journeys into the unknown, seeking to improve our understanding of nature and our place within it.

    Guiding these scientists is the spirit of inquiry so characteristic of the human race. It is this spirit that propelled humans upward along the evolutionary ladder, helping them reach their utmost heights. It prompted humankind to pursue agriculture, learn to build lodgings, invent writing, harness electricity to power emerging technologies, observe distant galaxies, design drugs to combat various diseases, develop new materials and decipher the genetic code embedded in all the plants and animals on Earth.

    The quest to maintain this increasing momentum compels Weizmann Institute scientists to seek out places that have not yet been reached by the human mind. What awaits us in these places? No one has the answer to this question. But one thing is certain – the journey fired by curiosity will lead onward to a better future.

     
  • richardmitnick 12:29 pm on January 15, 2019 Permalink | Reply
    Tags: , NPDGamma Experiment, , , Physics, Precision experiment first to isolate measure weak force between protons and neutrons,   

    From Oak Ridge National Laboratory: “Precision experiment first to isolate, measure weak force between protons, neutrons” 

    i1

    From Oak Ridge National Laboratory

    December 19, 2018
    Sara Shoemaker, Communications
    shoemakerms@ornl.gov
    865.576.9219

    1
    Scientists analyzed the gamma rays emitted during the NPDGamma Experiment and found parity-violating asymmetry, which is a specific change in behavior in the force between a neutron and a proton.

    2

    They measured a 30 parts per billion preference for gamma rays to be emitted antiparallel to the neutron spin when neutrons are captured by protons in liquid hydrogen. After observing that more gammas go down than up, the experiment resolved for the first time a mirror-asymmetric component or handedness of the weak force. Credit: Andy Sproles/Oak Ridge National Laboratory, U.S. Dept. of Energy.

    A team of scientists has for the first time measured the elusive weak interaction between protons and neutrons in the nucleus of an atom. They had chosen the simplest nucleus consisting of one neutron and one proton for the study.

    Through a unique neutron experiment at the Department of Energy’s Oak Ridge National Laboratory, experimental physicists resolved the weak force between the particles at the atom’s core, predicted in the Standard Model that describes the elementary particles and their interactions.

    Their result is sensitive to subtle aspects of the strong force between nuclear particles, which is still poorly understood.

    The team’s observation, described in Physical Review Letters, culminates decades of work performed with an apparatus known as NPDGamma. The first phase of the experiment took place at Los Alamos National Laboratory. Building on the knowledge gained at LANL, the team moved the project to ORNL to take advantage of the high neutron beam intensity produced at the lab’s Spallation Neutron Source.

    ORNL Spallation Neutron Source


    ORNL Spallation Neutron Source

    Protons and neutrons are made of smaller particles called quarks that are bound together by the strong interaction, which is one of the four known forces of nature: strong force, electromagnetism, weak force and gravity. The weak force exists in the tiny distance within and between protons and neutrons; the strong interaction confines quarks in neutrons and protons.

    The weak force also connects the axial spin and direction of motion of the nuclear particles, revealing subtle aspects of how quarks move inside protons and neutrons.

    “The goal of the experiment was to isolate and measure one component of this weak interaction, which manifested as gamma rays that could be counted and verified with high statistical accuracy,” said David Bowman, co-author and team leader for neutron physics at ORNL. “You have to detect a lot of gammas to see this tiny effect.”

    The NPDGamma Experiment, the first to be carried out at the Fundamental Neutron Physics Beamline at SNS, channeled cold neutrons toward a target of liquid hydrogen. The apparatus was designed to control the spin direction of the slow-moving neutrons, “flipping” them from spin-up to spin-down positions as desired. When the manipulated neutrons smashed into the target, they interacted with the protons within the liquid hydrogen’s atoms, sending out gamma rays that were measured by special sensors.

    After analyzing the gamma rays, the scientists found parity-violating asymmetry, which is a specific change in behavior in the force between a neutron and a proton. “If parity were conserved, a nucleus spinning in the righthanded way and one spinning in the lefthanded way—as if they were mirrored images—would result in an equal number of gammas emitting up as emitting down,” Bowman explained.

    “But, in fact, we observed that more gammas go down than go up, which lead to successfully isolating and measuring a mirror-asymmetric component of the weak force.”

    The scientists ran the experiment numerous times for about two decades, counting and characterizing the gamma rays and collecting data from these events based on neutron spin direction and other factors.

    The high intensity of the SNS, along with other improvements, allowed a count rate that is nearly 100 times higher compared with previous operation at the Los Alamos Neutron Science Center.

    Results of the NPDGamma Experiment filled in a vital piece of information, yet there are still theories to be tested.

    “There is a theory for the weak force between the quarks inside the proton and neutron, but the way that the strong force between the quarks translates into the force between the proton and the neutron is not fully understood,” said W. Michael Snow, co-author and professor of experimental nuclear physics at Indiana University. “That’s still an unsolved problem.”

    He compared the measurement of the weak force in relation with the strong force as a kind of tracer, similar to a tracer in biology that reveals a process of interest in a system without disturbing it.

    “The weak interaction allows us to reveal some unique features of the dynamics of the quarks within the nucleus of an atom,” Snow added.

    Co-authors of the study titled, “First Observation of P-odd γ Asymmetry in Polarized Neutron Capture on Hydrogen,” included co-principal investigators James David Bowman of ORNL and William Michael Snow of Indiana University (IU). The lead co-authors were David Blyth of Arizona State University and Argonne National Laboratory; Jason Fry of the University of Virginia and IU; and Nadia Fomin of the University of Tennessee, Knoxville, and Los Alamos National Laboratory. In total, 64 individuals from 28 institutions worldwide contributed to this research, and it produced more than 15 Ph.D. theses.

    The research was supported by DOE’s Office of Science and used resources of the Spallation Neutron Source at ORNL, a DOE Office of Science User Facility. It was also supported by the U.S. National Science Foundation, the Natural Sciences and Engineering Research Council of Canada, the Canadian Foundation for Innovation, the PAPIIT-UNAM and CONACYT agencies in Mexico, the German Academic Exchange Service and the Indiana University Center for Spacetime Symmetries.

    See the full article here .


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    ORNL is managed by UT-Battelle for the Department of Energy’s Office of Science. DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time.

    i2

     
  • richardmitnick 3:56 pm on January 14, 2019 Permalink | Reply
    Tags: , , , , , Physics   

    From Cornell Chronicle: “Next-gen particle accelerator is aim of Bright Beams work” 

    Cornell Bloc

    From Cornell Chronicle

    January 10, 2019
    Rick Ryan

    1
    Professor James Sethna, left, and postdoctoral theorist Danilo Liarte, both members of the Center for Bright Beams, are working toward more efficient particle accelerators. Provided.

    Particle accelerators have been used for decades to answer questions regarding the nuclei of atoms, the smallest forms of matter. New research is helping address current challenges and develop more efficient accelerators.

    Currently, particles get accelerated thanks to metallic chambers known as superconducting radio-frequency cavities. These chambers, also known as RF cavities, are spaced along a particle accelerator. As a beam of particles passes through a cavity, it is hit with energy from radio waves, causing it to accelerate. However, in order for the RF cavity to be superconducting, it must be cooled with liquid helium to near zero kelvins – approximately minus 460 degrees Fahrenheit – an expensive proposition.

    Another problem is dissipation of energy, in the form of heat, from the radio waves. Experimentalists traditionally have been able to bypass some of the negative impacts by carefully reducing the temperature of the RF cavity to well below the superconducting threshold. While this approach works, researchers are seeking a more efficient and lasting solution.

    Recently, theorists and experimentalists from the Center for Bright Beams (CBB) – a multi-institution National Science Foundation Science and Technology Center led by Cornell – published research that may help enhance the theoretical framework used to model future accelerators. The ultimate goal is to simplify the refrigeration needs for RF cavities while reducing RF power losses.

    Postdoctoral theorist Danilo Liarte is lead author of “Vortex Dynamics and Losses Due to Pinning: Dissipation from Trapped Magnetic Flux in Resonant Superconducting Radio-Frequency Cavities,” published Nov. 27 in Physical Review Applied. Senior authors are Cornell physics professors James Sethna and Matthias Liepe, both CBB members.

    The material of choice for today’s accelerating cavities is niobium, which becomes superconducting at a higher temperature than any other pure metal. “Higher” is relative, though: The operating temperature is minus 456 degrees Fahrenheit, or 2 kelvins, and requires costly cryogenic equipment to cool the cavity in a bath of liquid helium.

    “A current challenge in accelerator physics is to maximize the accelerating field, and minimize the dissipation (heat) within the superconducting cavity,” said Liarte, a member of the Sethna lab. “By understanding the power losses from having these theoretical models, we can better understand the material properties of the cavities.”

    Future accelerators, Liarte said, are likely to be compound superconductors such as triniobium-tin (Nb3Sn). These compounds have better intrinsic properties than niobium and could operate at a higher superconducting temperature – minus 452 degrees Fahrenheit, or 4.2 kelvins.

    While this jump in temperature may seem negligible, it can drastically reduce the costs of operating SRF cavities by eliminating the need for superfluid helium refrigeration.

    While understanding of Nb3Sn cavities is still limited, there are certain properties that can be better understood by looking at multiple types of superconductors.

    For their most recent study, the group collected data from three separate cavity treatments: niobium sprayed onto copper, Nb3Sn and niobium with impurities.

    Each of these materials provided insight into one of the most sought-after pieces of evidence for the negative impacts on accelerating cavities: vortex lines. Considered the “smoking gun” of superconducting cavities, these lines of errant magnetic fields within the cavity are surrounded by vortices of electrons that interfere with the desired radio waves.

    “Pretty much all of the superconducting materials that we use will have at least some vortex lines in them,” said contributor Peter Koufalis, a doctoral student in the Liepe group and a member of the Cornell Laboratory for Accelerator-based Sciences and Education (CLASSE). “It is very hard to completely get rid of them.”

    These vortices can get trapped within the active layer of the superconductor, creating magnetic fields that cause disarray within what should be a finely ordered system of acceleration. The vortex lines get trapped in the inevitable impurities of the cavity, the group found, and can dissipate RF power more quickly than earlier theorized.

    “What we have now is basically a model that explains this behavior in a quantitative and qualitative manner,” Liarte said.

    Other contributors to the study included Daniel Hall, Ph.D. ’17, from the Liepe group; doctoral student Alen Senanian from the Sethna group; and Akira Miyazaki of the European Organization for Nuclear Research (CERN) and the University of Manchester, England.

    This work, conducted at Cornell and CERN, was supported by the National Science Foundation and the U.S. Department of Energy.

    See the full article here .


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    Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

    Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

    On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

     
  • richardmitnick 11:31 am on January 8, 2019 Permalink | Reply
    Tags: , Antiuniverse, , , CPT symmetry, , Our universe has antimatter partner on the other side of the Big Bang say physicists, , Physics, , The entity that respects the symmetry is a universe–antiuniverse pair   

    From physicsworld.com: “Our universe has antimatter partner on the other side of the Big Bang, say physicists” 

    physicsworld
    From physicsworld.com

    03 Jan 2019

    1
    (Courtesy: shutterstock/tomertu)

    Our universe could be the mirror image of an antimatter universe extending backwards in time before the Big Bang. So claim physicists in Canada, who have devised a new cosmological model positing the existence of an “antiuniverse” [Physical Review Letters] which, paired to our own, preserves a fundamental rule of physics called CPT symmetry. The researchers still need to work out many details of their theory, but they say it naturally explains the existence of dark matter.

    Standard cosmological models tell us that the universe – space, time and mass/energy – exploded into existence some 14 billion years ago and has since expanded and cooled, leading to the progressive formation of subatomic particles, atoms, stars and planets.

    However, Neil Turok of the Perimeter Institute for Theoretical Physics in Ontario reckons that these models’ reliance on ad-hoc parameters means they increasingly resemble Ptolemy’s description of the solar system. One such parameter, he says, is the brief period of rapid expansion known as inflation that can account for the universe’s large-scale uniformity. “There is this frame of mind that you explain a new phenomenon by inventing a new particle or field,” he says. “I think that may turn out to be misguided.”

    Instead, Turok and his Perimeter Institute colleague Latham Boyle set out to develop a model of the universe that can explain all observable phenomena based only on the known particles and fields. They asked themselves whether there is a natural way to extend the universe beyond the Big Bang – a singularity where general relativity breaks down – and then out the other side. “We found that there was,” he says.

    The answer was to assume that the universe as a whole obeys CPT symmetry. This fundamental principle requires that any physical process remains the same if time is reversed, space inverted and particles replaced by antiparticles. Turok says that this is not the case for the universe that we see around us, where time runs forward as space expands, and there’s more matter than antimatter.

    2
    In a CPT-symmetric universe, time would run backwards from the Big Bang and antimatter would dominate (L Boyle/Perimeter Institute of Theoretical Physics)

    Instead, says Turok, the entity that respects the symmetry is a universe–antiuniverse pair. The antiuniverse would stretch back in time from the Big Bang, getting bigger as it does so, and would be dominated by antimatter as well as having its spatial properties inverted compared to those in our universe – a situation analogous to the creation of electron–positron pairs in a vacuum, says Turok.

    Turok, who also collaborated with Kieran Finn of Manchester University in the UK, acknowledges that the model still needs plenty of work and is likely to have many detractors. Indeed, he says that he and his colleagues “had a protracted discussion” with the referees reviewing the paper for Physical Review Letters [link is above] – where it was eventually published – over the temperature fluctuations in the cosmic microwave background. “They said you have to explain the fluctuations and we said that is a work in progress. Eventually they gave in,” he says.

    In very broad terms, Turok says, the fluctuations are due to the quantum-mechanical nature of space–time near the Big Bang singularity. While the far future of our universe and the distant past of the antiuniverse would provide fixed (classical) points, all possible quantum-based permutations would exist in the middle. He and his colleagues counted the instances of each possible configuration of the CPT pair, and from that worked out which is most likely to exist. “It turns out that the most likely universe is one that looks similar to ours,” he says.

    Turok adds that quantum uncertainty means that universe and antiuniverse are not exact mirror images of one another – which sidesteps thorny problems such as free will.

    But problems aside, Turok says that the new model provides a natural candidate for dark matter. This candidate is an ultra-elusive, very massive particle called a “sterile” neutrino hypothesized to account for the finite (very small) mass of more common left-handed neutrinos. According to Turok, CPT symmetry can be used to work out the abundance of right-handed neutrinos in our universe from first principles. By factoring in the observed density of dark matter, he says that quantity yields a mass for the right-handed neutrino of about 5×108 GeV – some 500 million times the mass of the proton.

    Turok describes that mass as “tantalizingly” similar to the one derived from a couple of anomalous radio signals spotted by the Antarctic Impulsive Transient Antenna (ANITA). The balloon-borne experiment, which flies high over Antarctica, generally observes cosmic rays travelling down through the atmosphere. However, on two occasions ANITA appears to have detected particles travelling up through the Earth with masses between 2 and 10×108 GeV. Given that ordinary neutrinos would almost certainly interact before getting that far, Thomas Weiler of Vanderbilt University and colleagues recently proposed that the culprits were instead decaying right-handed neutrinos [Letters in High Energy Physics].

    Turok, however, points out a fly in the ointment – which is that the CPT symmetric model requires these neutrinos to be completely stable. But he remains cautiously optimistic. “It is possible to make these particles decay over the age of the universe but that takes a little adjustment of our model,” he says. “So we are still intrigued but I certainly wouldn’t say we are convinced at this stage.”

    See the full article here .


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    Please help promote STEM in your local schools.


    Stem Education Coalition

    Perimeter Institute is the world’s largest research hub devoted to theoretical physics. The independent Institute was founded in 1999 to foster breakthroughs in the fundamental understanding of our universe, from the smallest particles to the entire cosmos. Research at Perimeter is motivated by the understanding that fundamental science advances human knowledge and catalyzes innovation, and that today’s theoretical physics is tomorrow’s technology. Located in the Region of Waterloo, the not-for-profit Institute is a unique public-private endeavour, including the Governments of Ontario and Canada, that enables cutting-edge research, trains the next generation of scientific pioneers, and shares the power of physics through award-winning educational outreach and public engagement.

    PhysicsWorld is a publication of the Institute of Physics. The Institute of Physics is a leading scientific society. We are a charitable organisation with a worldwide membership of more than 50,000, working together to advance physics education, research and application.

    We engage with policymakers and the general public to develop awareness and understanding of the value of physics and, through IOP Publishing, we are world leaders in professional scientific communications.
    IOP Institute of Physics

     
  • richardmitnick 10:13 am on January 8, 2019 Permalink | Reply
    Tags: , , , Infrared spectroscopy, Physics, , ,   

    From SLAC National Accelerator Lab: “Study shows single atoms can make more efficient catalysts” 

    From SLAC National Accelerator Lab

    January 7, 2019
    Glennda Chui

    1
    Scientists used a combination of four techniques, represented here by four incoming beams, to reveal in unprecedented detail how a single atom of iridium catalyzes a chemical reaction. (Greg Stewart/SLAC National Accelerator Laboratory)

    Detailed observations of iridium atoms at work could help make catalysts that drive chemical reactions smaller, cheaper and more efficient.

    Catalysts are chemical matchmakers: They bring other chemicals close together, increasing the chance that they’ll react with each other and produce something people want, like fuel or fertilizer.

    Since some of the best catalyst materials are also quite expensive, like the platinum in a car’s catalytic converter, scientists have been looking for ways to shrink the amount they have to use.

    Now scientists have their first direct, detailed look at how a single atom catalyzes a chemical reaction. The reaction is the same one that strips poisonous carbon monoxide out of car exhaust, and individual atoms of iridium did the job up to 25 times more efficiently than the iridium nanoparticles containing 50 to 100 atoms that are used today.

    The research team, led by Ayman M. Karim of Virginia Tech, reported the results in Nature Catalysis.

    “These single-atom catalysts are very much a hot topic right now,” said Simon R. Bare, a co-author of the study and distinguished staff scientist at the Department of Energy’s SLAC National Accelerator Laboratory, where key parts of the work took place. “This gives us a new lens to look at reactions through, and new insights into how they work.”

    Karim added, “To our knowledge, this is the first paper to identify the chemical environment that makes a single atom catalytically active, directly determine how active it is compared to a nanoparticle, and show that there are very fundamental differences – entirely different mechanisms – in the way they react.”

    Is smaller really better?

    Catalysts are the backbone of the chemical industry and essential to oil refining, where they help break crude oil into gasoline and other products. Today’s catalysts often come in the form of nanoparticles attached to a surface that’s porous like a sponge – so full of tiny holes that a single gram of it, unfolded, might cover a basketball court. This creates an enormous area where millions of reactions can take place at once. When gas or liquid flows over and through the spongy surface, chemicals attach to the nanoparticles, react with each other and float away. Each catalyst is designed to promote one specific reaction over and over again.

    But catalytic reactions take place only on the surfaces of nanoparticles, Bare said, “and even though they are very small particles, the expensive metal on the inside of the nanoparticle is wasted.”

    Individual atoms, on the other hand, could offer the ultimate in efficiency. Each and every atom could act as a catalyst, grabbing chemical reactants and holding them close together until they bond. You could fit a lot more of them in a given space, and not a speck of precious metal would go to waste.

    Single atoms have another advantage: Unlike clusters of atoms, which are bound to each other, single atoms are attached only to the surface, so they have more potential binding sites available to perform chemical tricks – which in this case came in very handy.

    Research on single-atom catalysts has exploded over the past few years, Karim said, but until now no one has been able to study how they function in enough detail to see all the fleeting intermediate steps along the way.

    Grabbing some help

    To get more information, the team looked at a simple reaction where single atoms of iridium split oxygen molecules in two, and the oxygen atoms then react with carbon monoxide to create carbon dioxide.

    They used four approaches­ – infrared spectroscopy, electron microscopy, theoretical calculations and X-ray spectroscopy with beams from SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL) – to attack the problem from different angles, and this was crucial for getting a complete picture.

    SLAC/SSRL

    SLAC SSRL Campus

    “It’s never just one thing that gives you the full answer,” Bare said. “It’s always multiple pieces of the jigsaw puzzle coming together.”

    The team discovered that each iridium atom does, in fact, perform a chemical trick that enhances its performance. It grabs a single carbon monoxide molecule out of the passing flow of gas and holds onto it, like a person tucking a package under their arm. The formation of this bond triggers tiny shifts in the configuration of the iridium atom’s electrons that help it split oxygen, so it can react with the remaining carbon monoxide gas and convert it to carbon dioxide much more efficiently.

    More questions lie ahead: Will this same mechanism work in other catalytic reactions, allowing them to run more efficiently or at lower temperatures? How do the nature of the single-atom catalyst and the surface it sits on affect its binding with carbon monoxide and the way the reaction proceeds?

    The team plans to return to SSRL in January to continue the 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

    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.

     
  • richardmitnick 12:58 pm on January 7, 2019 Permalink | Reply
    Tags: , , , Physics, Plasma is an electrically conductive mix of electrons and ions, , Rice University physicists are first to laser cool neutral plasma, Ultracold simulators of super-dense stars   

    From Rice University: ” Ultracold simulators of super-dense stars” 

    Rice U bloc

    From Rice University

    January 3, 2019
    Jade Boyd

    Rice University physicists are first to laser cool neutral plasma.

    Rice University physicists have created the world’s first laser-cooled neutral plasma, completing a 20-year quest that sets the stage for simulators that re-create exotic states of matter found inside Jupiter and white dwarf stars.

    The findings are detailed this week in the journal Science and involve new techniques for laser cooling clouds of rapidly expanding plasma to temperatures about 50 times colder than deep space.

    “We don’t know the practical payoff yet, but every time physicists have laser cooled a new kind of thing, it has opened a whole world of possibilities,” said lead scientist Tom Killian, professor of physics and astronomy at Rice. “Nobody predicted that laser cooling atoms and ions would lead to the world’s most accurate clocks or breakthroughs in quantum computing. We do this because it’s a frontier.”

    Killian and graduate students Tom Langin and Grant Gorman used 10 lasers of varying wavelengths to create and cool the neutral plasma. They started by vaporizing strontium metal and using one set of intersecting laser beams to trap and cool a puff of strontium atoms about the size of a child’s fingertip. Next, they ionized the ultracold gas with a 10-nanosecond blast from a pulsed laser. By stripping one electron from each atom, the pulse converted the gas to a plasma of ions and electrons.

    1
    Rice University physicists reported the first laser-cooled neutral plasma, a breakthrough that could lead to simulators for exotic states of matter that occur at the center of Jupiter or white dwarf stars. (Photo by Brandon Martin/Rice University)

    Energy from the ionizing blast causes the newly formed plasma to expand rapidly and dissipate in less than one thousandth of a second. This week’s key finding is that the expanding ions can be cooled with another set of lasers after the plasma is created. Killian, Langin and Gorman describe their techniques in the new paper, clearing the way for their lab and others to make even colder plasmas that behave in strange, unexplained ways.

    Plasma is an electrically conductive mix of electrons and ions. It is one of four fundamental states of matter; but unlike solids, liquids and gases, which are familiar in daily life, plasmas tend to occur in very hot places like the surface of the sun or a lightning bolt. By studying ultracold plasmas, Killian’s team hopes to answer fundamental questions about how matter behaves under extreme conditions of high density and low temperature.

    To make its plasmas, the group starts with laser cooling, a method for trapping and slowing particles with intersecting laser beams. The less energy an atom or ion has, the colder it is, and the slower it moves about randomly. Laser cooling was developed in the 1990s to slow atoms until they are almost motionless, or just a few millionths of a degree above absolute zero.

    2
    Rice University graduate student Tom Langin makes an adjustment to an experiment that uses dozens of lasers of varying wavelengths to laser-cool ions in a neutral plasma that is made by first laser-cooling strontium atoms and then ionizing them with a high-power laser. (Photo by Brandon Martin/Rice University)

    “If an atom or ion is moving, and I have a laser beam opposing its motion, as it scatters photons from the beam it gets momentum kicks that slow it,” Killian said. “The trick is to make sure that light is always scattered from a laser that opposes the particle’s motion. If you do that, the particle slows and slows and slows.”

    During a postdoctoral fellowship at the National Institute of Standards and Technology in Bethesda, Md., in 1999, Killian pioneered the ionization method for creating neutral plasma from a laser-cooled gas. When he joined Rice’s faculty the following year, he started a quest for a way to make the plasmas even colder. One motivation was to achieve “strong coupling,” a phenomenon that happens naturally in plasmas only in exotic places like white dwarf stars and the center of Jupiter.

    “We can’t study strongly coupled plasmas in places where they naturally occur,” Killian said. “Laser cooling neutral plasmas allows us to make strongly coupled plasmas in a lab, so that we can study their properties.

    “In strongly coupled plasmas, there is more energy in the electrical interactions between particles than in the kinetic energy of their random motion,” Killian said. “We mostly focus on the ions, which feel each other, and rearrange themselves in response to their neighbors’ positions. That’s what strong coupling means.”

    3
    To laser-cool a neutral plasma, Rice University physicists start by vaporizing billions of strontium atoms, which are laser-cooled and laser-ionized to create a rapidly expanding cloud of neutral ions. Another set of lasers cools the ions. (Photo by Brandon Martin/Rice University)

    Because the ions have positive electric charges, they repel one another through the same force that makes your hair stand up straight if it gets charged with static electricity.

    “Strongly coupled ions can’t be near one another, so they try to find equilibrium, an arrangement where the repulsion from all of their neighbors is balanced,” he said. “This can lead to strange phenomena like liquid or even solid plasmas, which are far outside our normal experience.”

    In normal, weakly coupled plasmas, these repulsive forces only have a small influence on ion motion because they’re far outweighed by the effects of kinetic energy, or heat.

    “Repulsive forces are normally like a whisper at a rock concert,” Killian said. “They’re drowned out by all the kinetic noise in the system.”

    In the center of Jupiter or a white dwarf star, however, intense gravity squeezes ions together so closely that repulsive forces, which grow much stronger at shorter distances, win out. Even though the temperature is quite high, ions become strongly coupled.

    4
    Rice University graduate student Tom Langin at the laser-table where beams of various wavelengths were used to make the world’s first ultracold neutral plasma. (Photo by Brandon Martin/Rice University)

    Killian’s team creates plasmas that are orders of magnitude lower in density than those inside planets or dead stars, but by lowering the temperature they raise the ratio of electric-to-kinetic energies. At temperatures as low as one-tenth of a Kelvin above absolute zero, Killian’s team has seen repulsive forces take over.

    “Laser cooling is well developed in gases of neutral atoms, for example, but the challenges are very different in plasmas,” he said.

    “We are just at the beginning of exploring the implications of strong coupling in ultracold plasmas,” Killian said. “For example, it changes the way that heat and ions diffuse through the plasma. We can study those processes now. I hope this will improve our models of exotic, strongly coupled astrophysical plasmas, but I am sure we will also make discoveries that we haven’t dreamt of yet. This is the way science works.”

    The research was supported by the Air Force Office of Scientific Research and the Department of Energy’s Office of Science.

    See the full article here .


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

    stem

    Stem Education Coalition

    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
  • richardmitnick 10:55 am on January 7, 2019 Permalink | Reply
    Tags: , , , NSF funds innovative stable isotope equipment at UC Santa Cruz, Physics, Stable Isotope Laboratory,   

    From UC Santa Cruz: “NSF funds innovative stable isotope equipment at UC Santa Cruz” 

    UC Santa Cruz

    From UC Santa Cruz

    January 02, 2019
    Tom Garlinghouse
    publicaffairs@ucsc.edu

    1
    Ocean Sciences Professor Matthew McCarthy (left) with lab manager Dyke Andreason in the UC Santa Cruz Stable Isotope Laboratory. (Photos by Carolyn Lagattuta)

    2
    With the new grant, the Stable Isotope Lab will acquire a cutting-edge instrument called an isotope-ratio-monitoring mass spectrometer (IRMS).

    A major grant from the National Science Foundation (NSF) will help fund the acquisition of a new state-of-the-art spectrometer for the Stable Isotope Laboratory at UC Santa Cruz.

    The $805,000 project for the new instrument was primarily supported by a $564,184 NSF grant, one of three awards the campus received this year from NSF’s highly competitive Major Research Instrumentation program. In addition, the Office of Research, the Division of Physical and Biological Sciences, the Division of Social Sciences, three departments and a research institute all contributed a total of $241,000 to fully fund the instrument expansion.

    Principal investigator Matthew McCarthy, a professor of ocean sciences, said the new equipment will support research across a wide range of disciplines, ranging from oceanography and earth science, paleontology, anthropology, ecology and fundamental biochemical cycle research.

    “We want our facility to be a place that diverse scientists from UC Santa Cruz and across our region can use,” McCarthy said. “My vision for this is to be a national and international center for novel and leading-edge stable isotope approaches.”

    Powerful tool

    Stable isotope analysis is a powerful tool for tracing carbon and nutrients as they cycle through food webs and the environment. UCSC’s Stable Isotope Laboratory, established in 1994, has been one of the world’s top facilities for research on climatic and oceanographic conditions in Earth’s past (paleoclimatology and paleoceanography). Scientists using the lab are at the forefront of research on, for example, ancient greenhouse climates, El Niño Southern Oscillation events, controls on rainfall in California, the vulnerability of species to global change, and other topics. According to McCarthy, research associated with the laboratory has generated over 165 scientific papers since 2004.

    Isotopes are different forms of the same element. The most common naturally occurring isotope of carbon, for example, is carbon–12 (the 12 refers to the number of protons and neutrons in the nucleus of the atom). Other carbon isotopes include carbon–14, which is unstable and emits radiation as it decays over time, and carbon–13, which is a stable isotope. While carbon–14 is useful for carbon dating, stable isotopes of carbon, nitrogen, and other elements are useful in a wide range of scientific analyses.

    Stable isotopes have proven especially valuable in the analysis of diet, where they can be used to distinguish between different sources of food. Isotopes in the food animals or humans eat are stored in their bones, teeth, and other tissues. By measuring the ratios of certain isotopes in tissue samples, researchers can determine, for example, where an animal fed and whether it ate primarily a marine, terrestrial, or freshwater diet. This ability has made stable isotopes an increasingly invaluable tool for not only ecology, but also paleontology, anthropology, and even forensics.

    With the new grant, the Stable Isotope Lab will acquire a cutting-edge instrument called an isotope-ratio-monitoring mass spectrometer (IRMS). McCarthy explained that the IRMS is a powerful tool for performing compound-specific isotope analysis (CSIA).

    CSIA is a way of measuring isotopes in individual molecules rather than bulk samples, which is the traditional method of stable isotope analysis. This application has proven especially useful for measuring isotope ratios of carbon and nitrogen in amino acids. This type of analysis is a relatively new but very promising field of study that “has exploded in the last 15 years,” McCarthy said.

    Innovative research

    The new spectrometer will also substantially modernize the existing isotope lab, which was last updated in 2004 and contains still usable but rapidly aging instruments that are now limited in their capabilities. With this new equipment, UC Santa Cruz will continue to be in the forefront of innovative research in the years to come, McCarthy said.

    “My vision for this project was really to not just expand things, but to make us a premier, cutting-edge place in the world to do compound-specific isotope analysis across different disciplines,” he said.

    CSIA can be used in a broad range of scientific disciplines, including oceanography, biology, ecology, astrobiology, paleontology, Earth science, and environmental studies. One expanding area at UCSC in which CSIA has proven of particular value is in anthropology and archaeology. Traditionally, bulk sample measurement of ratios between carbon–13 and nitrogen–15 in human bone collagen have helped to distinguish diets composed of, for example, animal protein versus plant protein or terrestrial versus marine diets.

    Recently, however, it is becoming increasingly clear that this technique is failing to provide adequate data in regions with complex ecosystems where diverse dietary resources are available. Compound-specific isotope analysis of individual amino acids, by contrast, can distinguish these more complex dietary regimes.

    Vicky Oelze, assistant professor in biological anthropology, sees great potential for CSIA in her research on the diets and ecology of apes and prehistoric humans. “I want to use the compound-specific approach to answer questions on meat consumption in wild chimpanzees, because the patterns we’re seeing with bulk isotopes are often super confusing,” Oelze said. “If this method works out, we have a much more precise tool we can use for future work on meat consumption frequencies in wild fauna.”

    CSIA will also be useful in a number of other areas, such as McCarthy’s research using deep-sea corals to look at millennial-scale oceanographic change. It can be used to investigate biogeochemical cycles, such as how land use changes have impacted nutrient dynamics in coastal and marine habitats, and for other applications such as studying the changes in food web dynamics in modern populations of marine mammals.

    If all goes well, the new isotope equipment will be installed and ready for use in standard applications in spring 2019, McCarthy said.

    The Stable Isotope Lab in the Earth and Marine Sciences building will be expanded to accommodate the new isotope-ratio-monitoring mass spectrometer. The lab will bring together scientists from different departments, divisions, and regional institutions, and will serve as a training ground for undergraduate and graduate students, as well as visiting researchers.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    UCSC Lick Observatory, Mt Hamilton, in San Jose, California, Altitude 1,283 m (4,209 ft)

    .

    UCO Lick Shane Telescope
    UCO Lick Shane Telescope interior
    Shane Telescope at UCO Lick Observatory, UCSC

    Lick Automated Planet Finder telescope, Mount Hamilton, CA, USA

    Lick Automated Planet Finder telescope, Mount Hamilton, CA, USA

    UC Santa Cruz campus
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

    UCSC is the home base for the Lick Observatory.

    Lick Observatory's Great Lick 91-centimeter (36-inch) telescope housed in the South (large) Dome of main building
    Lick Observatory’s Great Lick 91-centimeter (36-inch) telescope housed in the South (large) Dome of main building

    Search for extraterrestrial intelligence expands at Lick Observatory
    New instrument scans the sky for pulses of infrared light
    March 23, 2015
    By Hilary Lebow
    1
    The NIROSETI instrument saw first light on the Nickel 1-meter Telescope at Lick Observatory on March 15, 2015. (Photo by Laurie Hatch) UCSC Lick Nickel telescope

    Astronomers are expanding the search for extraterrestrial intelligence into a new realm with detectors tuned to infrared light at UC’s Lick Observatory. A new instrument, called NIROSETI, will soon scour the sky for messages from other worlds.

    “Infrared light would be an excellent means of interstellar communication,” said Shelley Wright, an assistant professor of physics at UC San Diego who led the development of the new instrument while at the University of Toronto’s Dunlap Institute for Astronomy & Astrophysics.

    Wright worked on an earlier SETI project at Lick Observatory as a UC Santa Cruz undergraduate, when she built an optical instrument designed by UC Berkeley researchers. The infrared project takes advantage of new technology not available for that first optical search.

    Infrared light would be a good way for extraterrestrials to get our attention here on Earth, since pulses from a powerful infrared laser could outshine a star, if only for a billionth of a second. Interstellar gas and dust is almost transparent to near infrared, so these signals can be seen from great distances. It also takes less energy to send information using infrared signals than with visible light.

    Frank Drake, professor emeritus of astronomy and astrophysics at UC Santa Cruz and director emeritus of the SETI Institute, said there are several additional advantages to a search in the infrared realm.

    “The signals are so strong that we only need a small telescope to receive them. Smaller telescopes can offer more observational time, and that is good because we need to search many stars for a chance of success,” said Drake.

    The only downside is that extraterrestrials would need to be transmitting their signals in our direction, Drake said, though he sees this as a positive side to that limitation. “If we get a signal from someone who’s aiming for us, it could mean there’s altruism in the universe. I like that idea. If they want to be friendly, that’s who we will find.”

    Scientists have searched the skies for radio signals for more than 50 years and expanded their search into the optical realm more than a decade ago. The idea of searching in the infrared is not a new one, but instruments capable of capturing pulses of infrared light only recently became available.

    “We had to wait,” Wright said. “I spent eight years waiting and watching as new technology emerged.”

    Now that technology has caught up, the search will extend to stars thousands of light years away, rather than just hundreds. NIROSETI, or Near-Infrared Optical Search for Extraterrestrial Intelligence, could also uncover new information about the physical universe.

    “This is the first time Earthlings have looked at the universe at infrared wavelengths with nanosecond time scales,” said Dan Werthimer, UC Berkeley SETI Project Director. “The instrument could discover new astrophysical phenomena, or perhaps answer the question of whether we are alone.”

    NIROSETI will also gather more information than previous optical detectors by recording levels of light over time so that patterns can be analyzed for potential signs of other civilizations.

    “Searching for intelligent life in the universe is both thrilling and somewhat unorthodox,” said Claire Max, director of UC Observatories and professor of astronomy and astrophysics at UC Santa Cruz. “Lick Observatory has already been the site of several previous SETI searches, so this is a very exciting addition to the current research taking place.”

    NIROSETI will be fully operational by early summer and will scan the skies several times a week on the Nickel 1-meter telescope at Lick Observatory, located on Mt. Hamilton east of San Jose.

    The NIROSETI team also includes Geoffrey Marcy and Andrew Siemion from UC Berkeley; Patrick Dorval, a Dunlap undergraduate, and Elliot Meyer, a Dunlap graduate student; and Richard Treffers of Starman Systems. Funding for the project comes from the generous support of Bill and Susan Bloomfield.

     
  • richardmitnick 1:23 pm on January 4, 2019 Permalink | Reply
    Tags: , , Cornell-Brookhaven “Energy-Recovery Linac” Test Accelerator or CBETA, , Physics, When it comes to particle accelerators magnets are one key to success   

    From Brookhaven National Lab: “Brookhaven Delivers Innovative Magnets for New Energy-Recovery Accelerator” 

    From Brookhaven National Lab

    January 2, 2019
    Karen McNulty Walsh
    kmcnulty@bnl.gov

    Test accelerator under construction at Cornell will reuse energy, running beams through multi-pass magnets that help keep size and costs down.

    1
    Members of the Brookhaven National Laboratory team with the completed magnet assemblies for the CBETA project.

    When it comes to particle accelerators, magnets are one key to success. Powerful magnetic fields keep particle beams “on track” as they’re ramped up to higher energy, crashed into collisions for physics experiments, or delivered to patients to zap tumors. Innovative magnets have the potential to improve all these applications.

    That’s one aim of the Cornell-Brookhaven “Energy-Recovery Linac” Test Accelerator, or CBETA, under construction at Cornell University and funded by the New York State Energy Research and Development Authority (NYSERDA). CBETA relies on a beamline made of cutting-edge magnets designed by physicists at the U.S. Department of Energy’s Brookhaven National Laboratory that can carry four beams at very different energies at the same time.

    Cornell BNL ERL test accelerator

    “Scientists and engineers in Brookhaven’s Collider-Accelerator Department (C-AD) just completed the production and assembly of 216 exceptional quality fixed-field, alternating gradient, permanent magnets for this project—an important milestone,” said C-AD Chair Thomas Roser, who oversees the Lab’s contributions to CBETA.

    The novel magnet design, developed by Brookhaven physicist Stephen Brooks and C-AD engineer George Mahler, has a fixed magnetic field that varies in strength at different points within each circular magnet’s aperture. “Instead of having to ramp up the magnetic field to accommodate beams of different energies, beams with different energies simply find their own ‘sweet spot’ within the aperture,” said Brooks. The result: Beams at four different energies can pass through a single beamline simultaneously.

    In CBETA, a chain of these magnets strung together like beads on a necklace will form what’s called a return loop that repeatedly delivers bunches of electrons to a linear accelerator (linac). Four trips through the superconducting radiofrequency cavities of the linac will ramp up the electrons’ energy, and another four will ramp them down so the energy stored in the beam can be recovered and reused for the next round of acceleration.

    “The bunches at different energies are all together in the return loop, with alternating magnetic fields keeping them oscillating along their individual paths, but then they merge and enter the linac sequentially,” explained C-AD chief mechanical engineer Joseph Tuozzolo. “As one bunch goes through and gets accelerated, another bunch gets decelerated and the energy recovered from the deceleration can accelerate the next bunch.”

    Even when the beams are used for experiments, the energy recovery is expected to be close to 99.9 percent, making this “superconducting energy recovery linac (ERL)” a potential game changer in terms of efficiency. New bunches of near-light-speed electrons are brought up to the maximum energy every microsecond, so fresh beams are always available for experiments.

    That’s one of the big advantages of using permanent magnets. Electromagnets, which require electricity to change the strength of the magnetic field, would never be able to ramp up fast enough, he explained. Using permanent fixed field magnets that require no electricity—like the magnets that stick to your refrigerator, only much stronger—avoids that problem and reduces the energy/cost required to run the accelerator.

    To prepare the magnets for CBETA, the Brookhaven team started with high-quality permanent magnet assemblies produced by KYMA, a magnet manufacturing company, based on the design developed by Brooks and Mahler. C-AD’s Tuozzolo organized and led the procurement effort with KYMA and the acquisition of the other components for the return loop.

    Engineers in Brookhaven’s Superconducting Magnet Division took precise measurements of each magnet’s field strength and used a magnetic field correction system developed and built by Brooks to fine-tune the fields to achieve the precision needed for CBETA. Mahler then led the assembly of the finished magnets onto girder plates that will hold them in perfect alignment in the finished accelerator, while C-AD engineer Robert Michnoff led the effort to build and test electronics for beam position monitors that will track particle paths through the beamline.

    “Brookhaven’s CBETA team reached the goals of this milestone nine days earlier than scheduled thanks to the work of extremely dedicated people performing multiple magnetic measurements and magnet surveys over many long work days,” Roser said.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    BNL Campus

    BNL NSLS-II


    BNL NSLS II

    BNL RHIC Campus

    BNL/RHIC Star Detector

    BNL RHIC PHENIX

    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.
    i1

     
  • richardmitnick 12:50 pm on January 4, 2019 Permalink | Reply
    Tags: , Nuclear phase diagram, , , Physics, , Star detector,   

    From Brookhaven National Lab: “Startup Time for Ion Collisions Exploring the Phases of Nuclear Matter” 

    From Brookhaven National Lab

    January 4, 2019
    Karen McNulty Walsh
    kmcnulty@bnl.gov
    (631) 344-8350 or

    Peter Genzer
    genzer@bnl.gov
    (631) 344-3174

    1
    The Relativistic Heavy Ion Collider (RHIC) is actually two accelerators in one. Beams of ions travel around its 2.4-mile-circumference rings in opposite directions at nearly the speed of light, coming into collision at points where the rings cross.

    BNL RHIC Campus

    January 2 marked the startup of the 19th year of physics operations at the Relativistic Heavy Ion Collider (RHIC), a U.S. Department of Energy Office of Science user facility for nuclear physics research at Brookhaven National Laboratory. Physicists will conduct a series of experiments to explore innovative beam-cooling technologies and further map out the conditions created by collisions at various energies. The ultimate goal of nuclear physics is to fully understand the behavior of nuclear matter—the protons and neutrons that make up atomic nuclei and those particles’ constituent building blocks, known as quarks and gluons.

    BNL RHIC Star detector

    2
    The STAR collaboration’s exploration of the “nuclear phase diagram” so far shows signs of a sharp border—a first-order phase transition—between the hadrons that make up ordinary atomic nuclei and the quark-gluon plasma (QGP) of the early universe when the QGP is produced at relatively low energies/temperatures. The data may also suggest a possible critical point, where the type of transition changes from the abrupt, first-order kind to a continuous crossover at higher energies. New data collected during this year’s run will add details to this map of nuclear matter’s phases.

    Many earlier experiments colliding gold ions at different energies at RHIC have provided evidence that energetic collisions create extreme temperatures (trillions of degrees Celsius). These collisions liberate quarks and gluons from their confinement with individual protons and neutrons, creating a hot soup of quarks and gluons that mimics what the early universe looked like before protons, neutrons, or atoms ever formed.

    “The main goal of this run is to turn the collision energy down to explore the low-energy part of the nuclear phase diagram to help pin down the conditions needed to create this quark-gluon plasma,” said Daniel Cebra, a collaborator on the STAR experiment at RHIC. Cebra is taking a sabbatical leave from his position as a professor at the University of California, Davis, to be at Brookhaven to help coordinate the experiments this year.

    STAR is essentially a house-sized digital camera with many different detector systems for tracking the particles created in collisions. Nuclear physicists analyze the mix of particles and characteristics such as their energies and trajectories to learn about the conditions created when ions collide.

    By colliding gold ions at various low energies, including collisions where one beam of gold ions smashes into a fixed target instead of a counter-circulating beam, RHIC physicists will be looking for signs of a so-called “critical point.” This point marks a spot on the nuclear phase diagram—a map of the phases of quarks and gluons under different conditions—where the transition from ordinary matter to free quarks and gluons switches from a smooth one to a sudden phase shift, where both states of matter can coexist.

    STAR gets a wider view

    STAR will have new components in place that will increase its ability to capture the action in these collisions. These include new inner sectors of the Time Projection Chamber (TPC)—the gas-filled chamber particles traverse from their point of origin in the quark-gluon plasma to the sensitive electronics that line the inner and outer walls of a large cylindrical magnet. There will also be a “time of flight” (ToF) wall placed on one of the STAR endcaps, behind the new sectors.

    “The main purpose of these is to enhance STAR’s sensitivity to signatures of the critical point by increasing the acceptance of STAR—essentially the field of view captured in the pictures of the collisions—by about 50 percent,” said James Dunlop, Associate Chair for Nuclear Physics in Brookhaven Lab’s Physics Department.

    “Both of these components have large international contributions,” Dunlop noted. “A large part of the construction of the iTPC sectors was done by STAR’s collaborating institutions in China. The endcap ToF is a prototype of a detector being built for an experiment called Compressed Baryonic Matter (CBM) at the Facility for Antiproton and Ion Research (FAIR) in Germany. The early tests at RHIC will allow CBM to see how well the detector components behave in realistic conditions before it is installed at FAIR while providing both collaborations with necessary equipment for a mutual-benefit physics program,” he said.

    Tests of electron cooling

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    A schematic of low-energy electron cooling at RHIC, from right: 1) a section of the existing accelerator that houses the beam pipe carrying heavy ion beams in opposite directions; 2) the direct current (DC) electron gun and other components that will produce and accelerate the bright beams of electrons; 3) the line that will transport and inject cool electrons into the ion beams; and 4) the cooling sections where ions will mix and scatter with electrons, giving up some of their heat, thus leaving the ion beam cooler and more tightly packed.

    Before the collision experiments begin in mid-February, RHIC physicists will be testing a new component of the accelerator designed to maximize collision rates at low energies.

    “RHIC operation at low energies faces multiple challenges, as we know from past experience,” said Chuyu Liu, the RHIC Run Coordinator for Run 19. “The most difficult one is that the tightly bunched ions tend to heat up and spread out as they circulate in the accelerator rings.”

    That makes it less likely that an ion in one beam will strike an ion in the other.

    To counteract this heating/spreading, accelerator physicists at RHIC have added a beamline that brings accelerated “cool” electrons into a section of each RHIC ring to extract heat from the circulating ions. This is very similar to the way the liquid running through your home refrigerator extracts heat to keep your food cool. But instead of chilled ice cream or cold cuts, the result is more tightly packed ion bunches that should result in more collisions when the counter-circulating beams cross.

    Last year, a team led by Alexei Fedotov demonstrated that the electron beam has the basic properties needed for cooling. After a number of upgrades to increase the beam quality and stability further, this year’s goal is to demonstrate that the electron beam can actually cool the gold-ion beam. The aim is to finish fine-tuning the technique so it can be used for the physics program next year.

    Berndt Mueller, Brookhaven’s Associate Laboratory Director for Nuclear and Particle Physics, noted, “This 19th year of operations demonstrates once again how the RHIC team — both accelerator physicists and experimentalists — is continuing to explore innovative technologies and ways to stretch the physics capabilities of the most versatile particle accelerator in the world.”

    See the full article here .


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