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  • richardmitnick 3:40 pm on September 24, 2015 Permalink | Reply
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    From SLAC: “Mysterious Neutrinos Take the Stage at SLAC” 

    SLAC Lab

    Of all known fundamental particles, neutrinos may be the most mysterious: Although they are highly abundant in the universe and were discovered experimentally in 1956, researchers still have a lot left to learn about them. To find out more about the elusive particles and their potential links to cosmic evolution, invisible dark matter and matter’s dominance over antimatter in the universe, the Department of Energy’s SLAC National Accelerator Laboratory is taking on key roles in four neutrino experiments: EXO, DUNE, MicroBooNE and ICARUS.

    Neutrinos were also the central theme of the 43rd annual SLAC Summer Institute for particle physics and astrophysics. The tradition-rich educational event, held Aug. 10-21, attracted more than 150 scientists from around the globe and featured lectures by some of the world’s leading neutrino experts.

    “Neutrinos are a hot research topic and have become a major focus of U.S. high-energy physics,” said SLAC theorist Thomas Rizzo, one of the summer school’s organizers. “There are many things we want to know about neutrinos. For instance, what are the masses of the known neutrinos? Are there other types of neutrinos that we don’t know about? Do neutrinos and antineutrinos behave differently? Or are neutrinos their own antiparticles?”

    Francis Halzen, principal investigator of the international IceCube Neutrino Observatory at the South Pole and neutrino specialist at the University of Wisconsin, gave the summer institute’s opening lecture.

    ICECUBE neutrino detector
    IceCube neutrino detector interior

    He said neutrinos have a high potential for scientific discovery – and they are also never boring. As a matter of fact, the history of neutrino research has seen a few surprising twists and turns.

    Neutrinos were the central theme of the 43rd annual SLAC Summer Institute for particle physics and astrophysics, which featured lectures by some of the world’s leading neutrino experts. (SLAC National Accelerator Laboratory)

    Elusive and Mysterious Neutrinos

    Neutrinos are one of the most common fundamental particles in the universe. They are abundantly produced in supernova explosions, star-powering nuclear fusion and other nuclear processes, resulting in trillions of neutrinos passing through us every minute. Yet, they are very difficult to study because they rarely interact with their surroundings and easily evade detection. This explains why it took researchers nearly 30 years to catch a first glimpse of neutrinos, although their existence had been first postulated in 1930 to explain an apparent violation of the conservation of energy in the radioactive decay of unstable atomic nuclei known as beta decay.

    A few years after the initial discovery in 1956, researchers were caught by surprise when more than one type of neutrino showed up in their experiments. By the turn of the millennium, they had identified three different types, or flavors, each associated with another fundamental charged partner particle: the electron, muon and tau.

    For the longest time, neutrinos were thought to be massless. But in 1998, scientists discovered that neutrinos frequently change from one flavor into another – a process called neutrino oscillation that can only occur if neutrinos do, in fact, have mass. Although the exact masses remain unknown, researchers estimate neutrinos to be two million times lighter than the next heavier particle, the electron, and this large mass difference is one of the great puzzles of neutrino physics.

    Neutrinos are abundantly produced in nuclear processes in the universe, for instance inside the sun. This image shows the sun in “neutrino light” as seen by the Super-Kamiokande neutrino detector in Japan. (Kamioka Observatory, ICRR, University of Tokyo)

    Super-Kamiokande experiment Japan
    Super-Kamiokande neutrino detector

    EXO: The Origin of the Neutrino Mass

    The origin of neutrino masses could be different from the origin of the masses of other particles. This could explain why neutrinos are incredibly light. One sign that this is true would be if they were their own antiparticles. This is only possible for neutrinos, since they carry no electric charge. The Enriched Xenon Observatory (EXO) is searching for a theorized rare nuclear process – neutrinoless double beta decay – that would prove that neutrinos and antineutrinos are identical.

    EXO experiment
    Part of the EXO-200 underground detector used to search for a hypothesized radioactive decay that could reveal how neutrinos acquire their incredibly small mass. (EXO Collaboration)

    Located almost half a mile underground at the Waste Isolation Pilot Plant in New Mexico, protected from cosmic radiation, the sensitive EXO experiment uses 200 kilograms of enriched liquid xenon that could potentially undergo the sought-after decay. If it exists, it would be so rare that it would take billions of times longer than the age of the universe for half of the radioactive xenon nuclei to decay. Only the large number of xenon atoms in the experiment allows researchers to search for such a long-lived decay.

    “Neutrinoless double beta decay would not only tell us that neutrinos must be their own antiparticles,” said SLAC particle physicist and EXO team member Martin Breidenbach. “From the measured decay rate, we could also determine the effective neutrino mass.”

    SLAC co-led the construction of the experiment’s 200-kilogram version (EXO-200), which also serves as a test bed for a more sensitive future ton-scale version (nEXO) that would give researchers a much better chance of seeing neutrinoless double beta decay.

    DUNE: Trio of Neutrino Masses and Matter-Antimatter Imbalance

    SLAC researchers are also taking part in another neutrino experiment – the Deep Underground Neutrino Experiment (DUNE), which will be constructed by a new international collaboration hosted at the Long-Baseline Neutrino Facility (LBNF) as the centerpiece of the particle physics program in the U.S.

    As part of LBNF, neutrinos and antineutrinos will be sent 800 miles through the Earth from Fermi National Accelerator Laboratory in Illinois to the DUNE detector in South Dakota – an “eye” for neutrinos that will eventually consist of four 10,000-ton modules of liquid argon. Scientists will then track how the particles morph from one neutrino flavor into another along the way.

    By comparing the oscillations of antineutrinos with those of neutrinos, DUNE researchers will be able to determine if the matter-antimatter siblings behave differently. If they do, the difference could potentially help explain why our universe is made of matter rather than antimatter.

    “Since each neutrino flavor interacts differently with the material in the Earth, the experiment will also tell us which of the three neutrino types is the lightest and which is the heaviest,” said researcher Mark Convery, who heads SLAC’s LBNF/DUNE group.

    DUNE’s liquid argon detector may also make other experiments possible. It could be used, for instance, to catch a glimpse of neutrino bursts from supernova explosions, which could tell us more about the physics of collapsing stars. Scientists at the joint SLAC/Stanford University Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) are particularly interested in this research opportunity.

    The future DUNE experiment will send neutrinos and antineutrinos 800 miles through the Earth to determine the relative masses of the three known neutrino types and study whether neutrinos and antineutrinos behave differently. (Fermi National Accelerator Laboratory)

    MicroBooNE and ICARUS: Search for Unknown Neutrinos

    However, DUNE will not be ready until the mid-2020s. In the meantime, Convery and his team are also engaging in the current MicroBooNE and future ICARUS experiments at Fermilab. These are so-called short-baseline experiments with detectors just hundreds of yards away from the neutrino source, rather than hundreds of miles away.

    FNAL MicroBooNE
    MicroBooNE detector


    “MicroBooNE and ICARUS will help us prepare for DUNE, but they also have the potential to discover completely new physics,” Convery said. “They’ll follow up on previous short-baseline studies that observed anomalies in neutrino oscillations.”

    Researchers believe that these anomalies could hint at the existence of a fourth, “sterile” neutrino. This hypothetical particle could potentially be linked to dark matter, the invisible substance that is five times more prevalent in the universe than regular matter.

    MicroBooNE’s 170-ton liquid argon detector began collecting data in August 2015, while ICARUS, which is three-and-a-half times heavier, is being upgraded at the European particle physics laboratory CERN. Both experiments will eventually become part of a three-detector short-baseline neutrino program at Fermilab, scheduled to launch in 2018 and designed to clarify whether previous hints at sterile neutrinos are correct or not.

    See the full article here .

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    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 10:42 am on August 31, 2015 Permalink | Reply
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    From SLAC: “World’s Most Powerful Digital Camera Sees Construction Green Light” 

    SLAC Lab

    August 31, 2015

    The LSST’s camera will include a filter-changing mechanism and shutter. This animation shows that mechanism at work, which allows the camera to view different wavelengths; the camera is capable of viewing light from near-ultraviolet to near-infrared (0.3-1 μm) wavelengths. (SLAC National Accelerator Laboratory)

    The Department of Energy has approved the start of construction for a 3.2-gigapixel digital camera – the world’s largest – at the heart of the Large Synoptic Survey Telescope (LSST). Assembled at the DOE’s SLAC National Accelerator Laboratory, the camera will be the eye of LSST, revealing unprecedented details of the universe and helping unravel some of its greatest mysteries.

    The construction milestone, known as Critical Decision 3, is the last major approval decision before the acceptance of the finished camera, said LSST Director Steven Kahn: “Now we can go ahead and procure components and start building it.”

    Starting in 2022, LSST will take digital images of the entire visible southern sky every few nights from atop a mountain called Cerro Pachón in Chile. It will produce a wide, deep and fast survey of the night sky, cataloguing by far the largest number of stars and galaxies ever observed. During a 10-year time frame, LSST will detect tens of billions of objects—the first time a telescope will observe more galaxies than there are people on Earth – and will create movies of the sky with unprecedented details. Funding for the camera comes from the DOE, while financial support for the telescope and site facilities, the data management system, and the education and public outreach infrastructure of LSST comes primarily from the National Science Foundation (NSF).

    The telescope’s camera – the size of a small car and weighing more than three tons – will capture full-sky images at such high resolution that it would take 1,500 high-definition television screens to display just one of them.

    Rendering of the LSST camera. SLAC is leading the construction of the 3.2-gigapixel camera, which will be the size of a small car and weigh more than 3 tons. The digital camera will be the largest ever built, allowing LSST to create an unprecedented archive of astronomical data that will help researchers study the formation of galaxies, track potentially hazardous asteroids, observe exploding stars and better understand mysterious dark matter and dark energy, which make up 95 percent of the universe. (SLAC National Accelerator Laboratory)

    In one shot, the Large Synoptic Survey Telescope’s 3.2-gigapixel camera will capture an area of the sky 40 times the size of the full moon (or almost 10 square degrees of sky). LSST’s large mirror and large field of view work together to deliver more light from faint astronomical objects than any optical telescope in the world. (SLAC National Accelerator Laboratory)

    This has already been a busy year for the LSST Project. Its dual-surface primary/tertiary mirror – the first of its kind for a major telescope – was completed; a traditional stone-laying ceremony in northern Chile marked the beginning of on-site construction of the facility; and a nearly 2,000-square-foot, 2-story-tall clean room was completed at SLAC to accommodate fabrication of the camera.

    “We are very gratified to see everyone’s hard work appreciated and acknowledged by this DOE approval,” said SLAC Director Chi-Chang Kao. “SLAC is honored to be partnering with the National Science Foundation and other DOE labs on this groundbreaking endeavor. We’re also excited about the wide range of scientific opportunities offered by LSST, in particular increasing our understanding of dark energy.”

    Components of the camera are being built by an international collaboration of universities and labs, including DOE’s Brookhaven National Laboratory, Lawrence Livermore National Laboratory and SLAC. SLAC is responsible for overall project management and systems engineering, camera body design and fabrication, data acquisition and camera control software, cryostat design and fabrication, and integration and testing of the entire camera. Building and testing the camera will take approximately five years.

    SLAC is also designing and constructing the NSF-funded database for the telescope’s data management system. LSST will generate a vast public archive of data—approximately 6 million gigabytes per year, or the equivalent of shooting roughly 800,000 images with a regular 8-megapixel digital camera every night, albeit of much higher quality and scientific value. This data will help researchers study the formation of galaxies, track potentially hazardous asteroids, observe exploding stars and better understand dark matter and dark energy, which together make up 95 percent of the universe but whose natures remain unknown.

    “We have a busy agenda for the rest of 2015 and 2016,” said Kahn. “Construction of the telescope on the mountain is well underway. The contracts for fabrication of the telescope mount and the dome enclosure have been awarded and the vendors are at full steam.”

    This exploded view of the LSST’s digital camera highlights its various components, including lenses, shutter and filters. (SLAC National Accelerator Laboratory)

    Nadine Kurita, camera project manager at SLAC, said fabrication of the state-of-the-art sensors for the camera has already begun, and contracts are being awarded for optical elements and other major components. “After several years of focusing on designs and prototypes, we are excited to start construction of key parts of the camera. The coming year will be crucial as we assemble and test the sensors for the focal plane.”

    The National Research Council’s Astronomy and Astrophysics decadal survey, Astro2010, ranked the LSST as the top ground-based priority for the field for the current decade. The recent report of the Particle Physics Project Prioritization Panel of the federal High Energy Physics Advisory Panel, setting forth the strategic plan for U.S. particle physics, also recommended completion of the LSST.

    “We’ve been working hard for years to get to this point,” said Kurita. “Everyone is very excited to start building the camera and take a big step toward conducting a deep survey of the Southern night sky.”

    LSST Exterior
    LSST Interior
    Housing the LSST in Chile at Cerro Pachón

    See the full article here.

    Please help promote STEM in your local schools.

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    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 1:13 pm on August 7, 2015 Permalink | Reply
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    From SLAC: “Unique SLAC Technology to Power X-ray Laser in South Korea” 

    SLAC Lab

    August 7, 2015

    In a diligent, two-month-long process, SLAC engineers tested the first of the XL4 klystrons built for PAL. (SLAC National Accelerator Laboratory)

    Accelerator technology pioneered at the Department of Energy’s SLAC National Accelerator Laboratory is on its way to powering X-ray science in South Korea: On Aug. 6, the lab shipped one of its unique radio-frequency amplifiers – an XL4 klystron – to Pohang Accelerator Laboratory (PAL), where it will become a key component for the optimal performance of a new X-ray free-electron laser under construction.

    Klystrons are the driving force behind many particle accelerators. They generate powerful radio-frequency fields that provide the energy to bring charged particles up to speed for collision experiments and the production of intense X-rays.

    However, SLAC’s XL4 klystron, which operates in a particular frequency range known as the X-band, will serve another purpose at PAL: It will power accelerator structures that let scientists optimize the electron beam in the future X-ray laser.

    “We are the world’s experts for X-band radio-frequency accelerator technology,” says SLAC’s Michael Fazio, who leads the lab’s Technology Innovation Directorate (TID). “PAL and SLAC have a collaborative agreement under which SLAC is providing klystrons and other accelerator components for the new X-ray laser.”

    Optimizing X-ray Laser Performance in South Korea

    PAL is building an X-ray laser similar to SLAC’s Linac Coherent Light Source (LCLS), a DOE Office of Science User Facility that generates the most powerful X-rays on Earth. With their extremely bright and ultrashort light pulses, X-ray lasers enable groundbreaking research in many scientific areas, from materials science to biology to studies of matter in extreme conditions.

    SLAC LCLS Inside
    LCLS interior

    These state-of-the-art light sources produce X-ray light by sending short electron bunches on a wavy path inside special magnets.

    “For the best X-ray laser performance, the electron bunches must be very short, on the order of only tens to hundreds of a quadrillionth of a second,” says SLAC engineer Erik Jongewaard, the project leader of the collaboration with PAL. “However, bunches produced by the laser’s electron source itself are too long and need to be shortened by bunch compressors.”

    This is where SLAC’s XL4 klystron comes in: It delivers energy to a so-called X-band linearizer – an accelerator structure that manipulates bunches in such a way that they can be optimally shortened in the subsequent bunch compressor.

    “This manipulation can conveniently be done in the X-band,” Jongewaard says. “When it comes to X-band accelerator technology, SLAC is the only place in the world where you can go from concept through design, engineering, fabrication, testing and operation all in one place and where the entire system can be specified and optimized.”

    For the South Korean X-ray laser project, PAL therefore began collaborating with SLAC in 2012.

    “Under the $3.4-million agreement, our team built the linearizer components including two XL4 klystrons,” says SLAC’s Lisa Bonetti, head of the TID Advanced Prototyping, Fabrication and Test Facilities department. “We also trained PAL engineers here on site in using our X-band technology.”

    The first klystron and other parts are now on their way to PAL. The second klystron, which will serve as a spare but could potentially also be used in a tool to diagnose the X-ray laser’s electron and X-ray beams, is currently being tested.

    Exporting Expertise Built on Decades of Research

    SLAC’s unparalleled expertise with X-band technology goes back to the 1980s when researchers began thinking about an energy upgrade of the lab’s 2-mile-long linear accelerator to enable new particle physics experiments. Given the choice of either building an even longer accelerator or developing klystrons that drive particles to higher energies, scientists opted for the latter. This marked the birth of SLAC’s X-band program.

    Although the linear accelerator never got its energy upgrade, the X-band technology kept developing. The latest klystron model is the XL4 – an extraordinarily stable radio-frequency source with 50 million watts of peak power. At SLAC, two of them are integrated into LCLS while others power experiments at the lab’s Next Linear Collider Test Accelerator (NLCTA) and Accelerator Structure Test Area (ASTA).

    “SLAC has built a total of 22 XL4 klystrons to date, including a modified version, called the XL5, for accelerator facilities in Europe,” Jongewaard says. “Three are used in Switzerland: one at CERN and two at the Paul Scherrer Institute. We also built another two for the Elettra research center in Italy.” The XL5 model is now commercially produced by Communications & Power Industries, a Palo Alto-based company.

    Soon, SLAC’s X-band radio-frequency technology will also benefit science in East Asia: Hopes are that PAL’s X-ray laser will produce its first light in 2016.

    Members of the Advanced Prototyping, Fabrication and Test Facilities department of SLAC’s Technology Innovation Directorate and engineers of the Pohang Accelerator Laboratory (PAL) in South Korea gather next to an XL4 klystron – a unique high-power radio-frequency amplifier used to accelerate and manipulate particle beams. Over the past 20 months, SLAC has built two klystrons and other parts needed to optimize the performance of PAL’s future X-ray laser. (SLAC National Accelerator Laboratory)

    See the full article here.

    Please help promote STEM in your local schools.

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    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 8:37 pm on August 5, 2015 Permalink | Reply
    Tags: , , Ultrafast electron diffraction (UED)   

    From SLAC: “SLAC Builds One of the World’s Fastest ‘Electron Cameras'” 

    SLAC Lab

    August 5, 2015

    Illustration of SLAC’s new apparatus for ultrafast electron diffraction – one of the world’s fastest “electron cameras” for some of the speediest motions in materials. (SLAC National Accelerator Laboratory)

    An electron gun (left), initially designed for SLAC’s X-ray laser LCLS, generates electrons that researchers send through materials (right) to study their structures and motions on the atomic level. (SLAC National Accelerator Laboratory)

    A new scientific instrument at the Department of Energy’s SLAC National Accelerator Laboratory promises to capture some of nature’s speediest processes. It uses a method known as ultrafast electron diffraction (UED) and can reveal motions of electrons and atomic nuclei within molecules that take place in less than a tenth of a trillionth of a second – information that will benefit groundbreaking research in materials science, chemistry and biology.

    “We’ve built one of the world’s best UED systems to create new research opportunities in ultrafast science,” says SLAC’s Xijie Wang, who is in charge of developing the new instrument described in a paper published July 24 in Review of Scientific Instruments. “Our apparatus delivers electron beams with a better quality than any other UED machine. For example, it allows us to study chemical processes in the gas phase that are up to four times faster than those we can examine with current UED technologies.”

    The technique complements ultrafast studies with SLAC’s X-ray free-electron laser. Similar to X-ray light, highly energetic electrons can take snapshots of the interior of materials as they pass through them. Yet, electrons interact differently with materials and “see” different things. Both methods combined draw a more complete picture that will help researchers better understand and possibly control important ultrafast processes in complex systems ranging from magnetic data storage devices to chemical reactions.

    ‘Seeing’ Ultrafast Processes with Electrons

    The superior performance of the new UED system is due to a very stable “electron gun” originally developed for SLAC’s X-ray laser Linac Coherent Light Source (LCLS), a DOE Office of Science User Facility. This electron source produces highly energetic electrons, packed into extremely short bunches. It spits out 120 of these bunches every second, generating a powerful electron beam that the researchers use to probe objects on the inside.

    But how can scientists actually catch a glimpse of the interior of materials with particles like electrons?

    The method works because particles have a second nature: They also behave like waves. When electron waves pass through a sample, they scatter off the sample’s atomic nuclei and electrons. The scattered waves then combine to form a so-called diffraction pattern picked up by a detector. The whole apparatus works like a high-speed camera, capturing differences in diffraction patterns over time that scientists use to reconstruct the sample’s inner structure and how it changes.

    Since electron bunches in SLAC’s UED instrument are extremely short, they reveal changes that occur in less than 100 quadrillionths of a second, or 100 femtoseconds, for instance in response to ultrashort laser pulses.

    “UED has been under development for the past 10 to 15 years, but the repulsive forces between electrons in the electron beam limited the time resolution of previous experiments,” says the paper’s first author Stephen Weathersby, the facility manager of SLAC’s Accelerator Structure Test Area (ASTA), where the UED machine is installed. “LCLS expertise in electron gun technology and ultrafast laser systems gives our system the performance and stability needed to study much faster processes.”

    This animation explains how researchers use high-energy electrons at SLAC to study faster-than-ever motions of atoms and molecules relevant to important material properties and chemical processes.

    Electrons Plus X-rays for Ultrafast Science

    Electrons behave similarly to X-rays in the way they explore speedy phenomena in nature. Electrons scatter off both electrons and atomic nuclei in materials. X-rays, on the other hand, interact only with electrons. Therefore, electron and X-ray studies of very fast structural changes complement each other.

    The SLAC-led team has already begun to combine both approaches to better understand the link between the magnetic behavior of certain materials and their structural properties in studies that could help develop next-generation data storage devices.

    Electrons also provide a path to studies that are very challenging to perform with X-rays.

    “Electrons interact with materials much more strongly than X-rays do,” says SLAC’s Renkai Li, the paper’s lead author. “We were able to analyze samples such as very thin films whose X-ray signals would be very weak.”

    For instance, the researchers studied a single atomic layer of a material that is interesting for future electronic devices.

    “Another interesting case is gas phase samples,” Li says. “Due to the almost 1,000-fold shorter wavelength of electrons compared to X-rays, UED can see much finer structural details. We’re able to see how atoms in molecules move with UED, which is an important step toward making molecular movies of ultrafast chemical reactions.”

    Ultrafast electron diffraction patterns of single-crystal gold (left) and nitrogen gas (right) obtained with SLAC’s new experimental setup. By analyzing changes in patterns like these, scientists learn about motions in materials that take place in less than 100 quadrillionths of a second. (SLAC National Accelerator Laboratory)

    Adding ‘Ultrasmall’ to the Mix

    The researchers have already mapped out the next steps to further improve the UED instrument.

    They plan on making it even faster – corresponding to a camera with a shutter speed close to 10 femtoseconds – and will eventually reduce the size of the electron beam from its current 100 microns – the diameter of an average human hair – to below one micron. These advances could be used to investigate how ultrafast motions in tiny regions of materials are linked to magnetism and other material properties.

    The scientists’ ultimate goal is to turn UED into an ultrafast electron microscope – an instrument that would show details too small to be seen with an optical microscope. Existing electron microscopes can already capture events in 10 billionths of a second, but with SLAC’s instrument, the researchers hope to push the speed limit to processes that are 1,000 times faster.

    “Ultrafast electron microscopy will bring two established, independent communities together: researchers working in electron microscopy and in ultrafast X-ray science,” says co-author Hermann Dürr of SLAC, who is one of the project’s science coordinators. “This will generate unforeseen possibilities for ultrafast science with electrons, similar to the great things we saw happening a few years ago at LCLS, when laser science and X-ray science merged into the new field of ultrafast X-ray science.”

    In addition to researchers from SLAC and Stanford University, the research team included scientists from the University of Nebraska, Lincoln, and the University of Duisburg-Essen in Germany.

    SLAC scientists Stephen Weathersby (left) and Renkai Li (right) working at the lab’s instrument for ultrafast electron diffraction – one of the world’s fastest electron cameras. (SLAC National Accelerator Laboratory)

    Members of SLAC’s team for ultrafast electron diffraction. (SLAC National Accelerator Laboratory)

    See the full article here.

    Please help promote STEM in your local schools.

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    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 2:55 pm on July 24, 2015 Permalink | Reply
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    From SLAC: “SLAC and DESY Join Forces at Bilateral Strategy Meeting” 

    SLAC Lab

    July 24, 2015

    The German research center DESY and SLAC will work closer together in the future: That was the outcome of a meeting of senior managers of both labs who convened July 16-17 at SLAC to discuss a joint strategy for more collaboration.

    On the first day, SLAC and DESY representatives talked about their labs’ current research activities and future plans, exposing a variety of commonalities and also differences between the research centers. This led to discussions on the second day that identified areas where the labs can best collaborate with each other.

    The meeting’s attendees found plenty of common ground. They compiled a comprehensive list of common interests, including advancements in X-ray laser technology, particle physics detectors, future compact accelerators and computing methods to handle ever-increasing amounts of scientific data produced in X-ray, particle physics and cosmology experiments.

    “SLAC and DESY have so many things in common, and we already work on many projects together,” said SLAC Director Chi-Chang Kao. “Meetings like this help us identify how we can work on the most challenging problems even closer and better together.”

    Helmut Dosch, the chairman of DESY’s board of directors, added, “The meeting was a wonderful opportunity to openly discuss the potential that the two world-class research centers have together.”

    The first DESY-SLAC strategy meeting at SLAC, July 16-17, 2015. Left to right: Michael Fazio, SLAC ALD, Technology Innovation Directorate; Mike Dunne, SLAC ALD, LCLS; Vitaly Yakimenko, SLAC division director, FACET; Joachim Mnich, DESY Particle Physics and Astroparticle Physics director; Norbert Holtkamp, SLAC deputy director; Helmut Dosch, chairman of the DESY board of directors; Kelly Gaffney, SLAC ALD, SSRL; Mike Willardson, SLAC tech transfer chief; Christian Scherf, DESY administrative director; Chi-Chang Kao, SLAC director; Edgar Weckert, DESY Photon Science director; David MacFarlane, SLAC chief research officer; Reinhard Brinkmann, DESY Accelerator Division director; Mark Hartney, SLAC director for strategic planning; Bill White, SLAC deputy director for LCLS Operations; Arik Willner, DESY team leader for business development; Bob Hettel, SLAC deputy ALD, Accelerator Directorate; John Galayda, SLAC project director, LCLS-II; Steven Kahn, SLAC project director, LSST. (SLAC National Accelerator Laboratory)

    SLAC and DESY share a rich history of collaboration and competition. Founded only a few years apart some 50 years ago, both centers were conceived as accelerator labs for particle physics experiments. Over the years, X-rays – an initially unwanted byproduct of particle accelerators – have become an increasingly important tool for science in both locations. Today, SLAC and DESY are multipurpose labs with similarly broad research programs, including accelerator research, particle physics, cosmology, X-ray science, bioscience, chemistry and materials science.

    Cross-fertilization between disciplines has helped both sides to stay at the forefront of science over the past decades. Similarly, developing a common strategy for cross-fertilization between the labs may further advance technologies that both research centers will need for their continued pursuit of groundbreaking science in the decades to come.

    The meeting was the first of its kind, kicking off future regular collaboration meetings of the two labs.

    SLAC and DESY will now form bilateral working groups to flesh out detailed proposals for more collaboration in the identified areas. Senior managers plan on meeting again next year, this time at DESY, to discuss the outcome of the screening process and put some of the proposals forward.

    “The meeting was very successful. It showed how much DESY and SLAC overlap in their vision of the future,” said SLAC Deputy Director Norbert Holtkamp, who set up this year’s meeting. “We now have to turn ideas on collaboration into action. Exchange of staff in strategic areas of common interest will also play an important role in this process.”

    See the full article here.

    Please help promote STEM in your local schools.

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    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 4:11 pm on July 23, 2015 Permalink | Reply
    Tags: , , , Studying a lab   

    From SLAC: “Social Scientist Chooses SLAC as Case Study for Transformation of ‘Big Science'” 

    SLAC Lab

    July 23, 2015

    A Swedish social scientist who has been studying the Department of Energy’s SLAC National Accelerator Laboratory for nearly a decade says it represents an ideal case study for how a national lab transforms from a primary mission in particle physics to a much broader mix of research fields.

    Olof Hallonsten of Lund University specializes in studying the policies and practices of “big science” labs – labs that operate large-scale research facilities. His work highlights the forces that set priorities for Big Science and drive research in new directions, and he plans to eventually publish a book about SLAC that combines material from previous studies.

    Olof Hallonsten

    “The history deserves telling,” Hallonsten said. “There is too little written about SLAC.”

    Before his time at SLAC, he participated in a study of a science lab in Sweden and became one of the first to join a PhD program in research policy at his university. “I got so interested in this science that I had hardly heard about before. I was really interested in the politics of the Big Science labs,” he said.

    Starting in 2007, he visited SLAC several times, interviewing Nobel laureates and past and present SLAC and Stanford administrators and carefully combing through the lab archives.

    ‘A Full-scale Transformation’

    “The more I learned about SLAC, the more it became clear to me that this was one of the most exciting examples of a full-scale transformation,” Hallonsten said. “All that glorious history in particle physics – and then it manages to reinvent itself and renew itself.

    “Such a transformation cannot just happen by political leadership or by genius scientists making a case for a new direction. It has to be a combination, and I just wanted to learn more about it.”

    Hallonsten has written book chapters and research papers about other science facilities in the U.S. and abroad, and about parallels in the changing focus of research at SLAC and Germany’s DESY lab. Both labs evolved from a particle physics focus into more diverse disciplines, including “photon science,” which includes X-ray research and more broadly the interaction of light with matter.

    Ingolf Lindau, a native of Sweden who is a professor emeritus at Stanford and SLAC, had helped Hallonsten with his early research and suggested SLAC as a possible study subject.

    “Ingolf said, ‘You should definitely go to SLAC, because it’s such an exciting story,’ ” Hallonsten said. “I had nothing against going to California for a couple of months.”

    He added, “People were very generous with information. The SLAC archives are absolutely amazing. The staff are really helpful; they have a really good system. For me, as a social scientist, it was like a gold mine.”

    Witness to a ‘Pivotal’ Period

    Looking back on his first visit in 2007, Hallonsten realized he had witnessed a pivotal time in the lab’s history, when it was rapidly transitioning away from a primary focus in particle physics.

    The lab’s premier particle physics project of that era, called BaBar, shut down in 2008 along with the PEP-II ring, which had accelerated electrons and their antiparticles for collisions that would allow scientists to study the imbalance between matter and antimatter that shapes our universe.

    Not far behind was the turn-on of the Linac Coherent Light Source (LCLS) X-ray laser in 2009. It would provide a powerful new source of X-rays to complement and extend the types of experiments that SLAC’s first X-ray research facility, now known as the Stanford Synchrotron Radiation Lightsource (SSRL), had enabled. Both are DOE Office of Science User Facilities.

    SLAC LCLS Inside

    SLAC SSRL Tunnel

    LCLS, Hallonsten said, began “like a snowball” with preliminary discussions in the early 1990s and then “rose to an avalanche” of support. The launch of LCLS cemented SLAC among the world’s premier photon science labs, he said: “LCLS and photon science had become the ‘new big thing.'”

    Growth of Synchrotron Research at SLAC

    One of his major research focuses at SLAC has been the birth and growth of SSRL as a window into larger changes at the lab.

    Launched in July 1973 as a Stanford pilot project, by 1974 it became the Stanford Synchrotron Radiation Project (SSRP), a National Science Foundation-funded national user facility. It extracted synchrotron radiation – waste X-ray light from an accelerator beam used in particle collider experiments – for research in a wide range of fields.

    A DOE user facility since 1982, SSRL now operates 33 experimental stations, drawing more than 1,500 scientists from around the globe each year.

    At first these synchrotron radiation experiments were defined as a “parasitic” use that was not allowed to interfere with particle physics experiments, and they were sometimes suspended or greatly curtailed.

    But tapping synchrotron radiation as a discovery tool in biology, materials science and other fields became a global trend that “can be thought of as almost a force of nature,” Hallonsten said. “It seems like it couldn’t be stopped.”

    Hallonsten credits concerted and continuing local efforts by SLAC and Stanford administrators and scientists, along with support from national agencies, for finding ways to support and grow synchrotron research at SSRP and then SSRL by changing national and laboratory-level priorities. From its modest beginnings, SSRL developed into an internationally known facility that has contributed to Nobel Prize-winning research.

    “It’s quite clear to me that it was not by accident that SSRL beat down all those struggles and all those obstacles,” Hallonsten said. “It was by producing good science.”

    See the full article here.

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    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 1:19 pm on July 22, 2015 Permalink | Reply
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    From SLAC: “Long-sought Discovery Fills in Missing Details of Cell ‘Switchboard'” 

    SLAC Lab

    July 22, 2015

    SLAC’s X-ray Laser Lends New Insight into Key Target for Drug Development

    A biomedical breakthrough, published today in the journal Nature, reveals never-before-seen details of the human body’s cellular switchboard that regulates sensory and hormonal responses. The work is based on an X-ray laser experiment at the Department of Energy’s SLAC National Accelerator Laboratory.

    The much-anticipated discovery, a decade in the making, could have broad impacts on development of more highly targeted and effective drugs with fewer side effects to treat conditions including high blood pressure, diabetes, depression and even some types of cancer.

    This video shows a 3-D rendering of a tiny signaling switch found in cells that involves arrestin (magenta), an important signaling protein, while docked with rhodopsin (green), a light-sensitive protein that is a type of G protein-coupled receptor (GPCR) found in the retina of our eyes. The cyan structure at the top is a protein called lysozyme that scientists added to more easily preserve and study the arrestin and rhodopsin structures. An experiment at SLAC’s Linac Coherent Light Source, an X-ray laser, provided this first-ever atomic-scale map of arrestin coupled to a GPCR. (SLAC National Accelerator Laboratory)

    The study has been hailed by researchers familiar with the work as one of the most important scientific results to date using SLAC’s Linac Coherent Light Source (LCLS), a DOE Office of Science User Facility that is one of the brightest sources of X-rays on the planet. The LCLS X-rays are a billion times brighter than those from synchrotrons and produce higher-resolution images while allowing scientists to use smaller samples.

    In crystallography experiments at the Coherent X-ray Imaging experimental station at LCLS, a liquid jet delivers nanoscale crystals into this chamber, where X-ray laser pulses strike them. (SLAC National Accelerator Laboratory)

    This illustration shows arrestin (yellow), an important type of signaling protein, while docked with rhodopsin (orange), a G protein-coupled receptor. GPCRs are embedded in cell membranes and serve an important role in a cellular signaling network. An experiment conducted at SLAC’s Linac Coherent Light Source X-ray laser provided an atomic-scale 3-D map of this joined structure. (SLAC National Accelerator Laboratory)

    These ultrabright X-rays enabled the research team to complete the first 3-D atomic-scale map of a key signaling protein called arrestin while it was docked with a cell receptor involved in vision. The receptor is a well-studied example from a family of hundreds of G protein-coupled receptors, or GPCRs, which are targeted by about 40 percent of drugs on the market. Its structure while coupled with arrestin provides new insight into the on/off signaling pathways of GPCRs.

    The research, led by scientists at the Van Andel Research Institute in Michigan in collaboration with dozens of other scientists from around the globe, represents a major milestone in GPCR structural studies, said Dr. Jeffrey L. Benovic, a biochemistry and molecular biology professor at Thomas Jefferson University in Philadelphia who specializes in such research but was not a part of this study.

    “This work has tremendous therapeutic implications,” Benovic said. “The study is a critical first step and provides key insight into the structural interactions in these protein complexes.”

    Decoding the Body’s Cellular ‘Switchboard’

    Arrestins and another class of specialized signaling proteins called G proteins take turns docking with GPCRs. Both play critical roles in the body’s communications “switchboard,” sending signals that the receptors translate into cell instructions. These instructions are responsible for a range of physiological functions.

    Until now, only a G protein had been seen joined to a receptor at this scale, one of the discoveries recognized with the 2012 Nobel Prize in Chemistry. Before the study at SLAC, little was known about how arrestins – which serve a critical role as the “off” switch in cell signaling, opposite the “on” switch of G proteins – dock with GPCRs, and how this differs from G protein docking. The latest research helps scientists understand how a docked arrestin can block a G protein from docking at the same time, and vice versa.

    Many of the available drugs that activate or deactivate GPCRs block both G proteins and arrestins from docking.

    “The new paradigm in drug discovery is that you want to find this selective pathway – how to activate either the arrestin pathway or the G-protein pathway but not both — for a better effect,” said Eric Xu, a scientist at the Van Andel Research Institute in Michigan who led the experiment. The study notes that a wide range of drugs would likely be more effective and have fewer side effects with this selective activation.

    X-ray Laser Best Tool for Tiny Samples

    Xu said he first learned about the benefits of using SLAC’s X-ray laser for protein studies in 2012. The microscopic arrestin-GPCR crystals, which his team had painstakingly produced over years, proved too difficult to study at even the most advanced type of synchrotron, a more conventional X-ray source.

    In the LCLS experiments, Xu’s team used samples of a form of human rhodopsin – a GPCR found in the retina whose dysfunction can cause night blindness – fused to a type of mouse arrestin that is nearly identical to human arrestin. Measuring just thousandths of a millimeter, the crystals – which had been formed in a toothpaste-like solution – were oozed into the X-ray pulses at LCLS, producing patterns that when combined and analyzed allowed researchers to reconstruct a complete 3-D map of the protein complex

    “While this particular sample serves a specific function in the body, people may start to use this research as a model for how GPCRs, in general, can interact with signaling proteins,” Xu said. His team had been working toward this result since 2005.

    SLAC Director Chi-Chang Kao said of the research milestone, “This important work is a prime example of how SLAC’s unique combination of cutting-edge scientific capabilities, including its expertise in X-ray science and structural biology, are playing key roles in high-impact scientific discoveries.”

    Data Analysis Helps Fill in Missing Piece

    Qingping Xu, a scientist in the Joint Center for Structural Genomics at SLAC’s Stanford Synchrotron Radiation Lightsource who helped to solve the 3-D structure, said it took many hours of computer modeling and data analysis to help understand and refine its details.

    “This structure is especially important because it fills in a missing piece about protein-binding pathways for GPCRs,” he said. Even so, he noted that much work remains in determining the unique structures and docking mechanisms across the whole spectrum of GPCRs and associated signaling proteins.

    Eric Xu said his group hopes to conduct follow-up studies at LCLS with samples of GPCRs bound to different types of signaling proteins.

    In addition to scientists from SLAC, including LCLS and SSRL’s Joint Center for Structural Genomics, and the Van Andel Research Institute, the study also included researchers from: Arizona State University, University of Southern California, DESY lab’s Center for Free Electron Laser Science in Germany, National University of Singapore, New York Structural Biology Center, The Scripps Research Institute, University of California, Los Angeles, University of Toronto, Vanderbilt University, Beijing Computational Science Research Center in China, the University of Wisconsin-Milwaukee, Chinese Academy of Sciences, Paul Scherrer Institute in Switzerland, Trinity College in Ireland, University of Chicago, University of Konstanz in Germany, Chinese Academy of Sciences, Center for Ultrafast Imaging in Germany, and University of Toronto.

    See the full article here.

    Please help promote STEM in your local schools.

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    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 12:03 pm on May 28, 2015 Permalink | Reply
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    From SLAC: “Spiraling Laser Pulses Could Change the Nature of Graphene” 

    SLAC Lab

    May 27, 2015

    This illustration depicts the structure of graphene, which consists of a single layer of carbon atoms arranged in a honeycomb pattern. A new simulation suggests that spiraling pulses of polarized laser light could change graphene’s nature, turning it from a metal to an insulator. Led by researchers at SLAC and Stanford, the study paves the way for experiments that create and control new states of matter with this specialized form of light. (AlexanderAlUS via Wikimedia Commons)

    A new study predicts that researchers could use spiraling pulses of laser light to change the nature of graphene, turning it from a metal into an insulator and giving it other peculiar properties that might be used to encode information.

    The results, published May 11 in Nature Communications, pave the way for experiments that create and control new states of matter with this specialized form of light, with potential applications in computing and other areas.

    “It’s as if we’re taking a piece of clay and turning it into gold, and when the laser pulse goes away the gold goes back to clay,” said Thomas Devereaux, a professor at the Department of Energy’s SLAC National Accelerator Laboratory and director of the Stanford Institute for Materials and Energy Sciences (SIMES), a joint SLAC/Stanford institute.

    “But in this case,“ he said, “our simulations show that we could theoretically change the electronic properties of the graphene, flipping it back and forth from a metallic state, where electrons flow freely, to an insulating state. In digital terms this is like flipping between zero and one, on and off, yes and no; it can be used to encode information in a computer memory, for instance. What makes this cool and interesting is that you could make electronic switches with light instead of electrons.”

    Devereaux led the study with Michael Sentef, who began the work as a postdoctoral researcher at SLAC and is now at the Max Planck Institute for the Structure and Dynamics of Matter in Germany.

    Tweaking a wonder material

    Graphene is a pure form of carbon just one atom thick, with its atoms arranged in a honeycomb pattern. Celebrated as a wonder material since its discovery 12 years ago, it’s flexible, nearly transparent, a superb conductor of heat and electricity and one of the strongest materials known. But despite many attempts, scientists have not found a way to turn it into a semiconductor – the material at the heart of microelectronics.

    An earlier study demonstrated that it might be possible to take a step in that direction by hitting a material with circularly polarized light – light that spirals either clockwise or counterclockwise as it travels, a quality that can also be described as right- or left-handedness. This would create a “band gap,” a range of energies that electrons cannot occupy, which is one of the hallmarks of a semiconductor.

    In the SIMES study, theorists used the DOE’s National Energy Research Scientific Computing Center at Lawrence Berkeley National Laboratory to perform large-scale simulations of an experiment in which graphene is hit with circularly polarized pulses a few millionths of a billionth of a second long.

    Getting as close to real as possible

    “Previous studies were based on analytical calculations and on idealized situations,” said Martin Claassen, a Stanford graduate student in Devereaux’s group who made key contributions to the study. “This one tried to simulate what happens in as close to real experimental conditions as you can get, right down to the shape of the laser pulses. Doing such a simulation can tell you what types of experiments are feasible and identify regions where you might find the most interesting changes in those experiments.”

    The simulations show that the handedness of the laser light would interact with a slight handedness in the graphene, which is not entirely uniform. This interaction leads to interesting and unexpected properties, said SLAC staff scientist and study co-author Brian Moritz. Not only does it produce a band gap, but it also induces a quantum state in which the graphene has a so-called “Chern number” of either one or zero, which results from a phenomenon known as Berry curvature and offers another on/off state that scientists might be able to exploit.

    Insights go beyond graphene

    While this study does not immediately open ways to make electronic devices, it does give researchers fundamental insights that advance the science in that direction. The results are also relevant to materials called dichalcogenides (pronounced dye-cal-CAW-gin-eyeds), which are also two-dimensional sheets of atoms arranged in a honeycomb structure.

    Dichalcogenides are the focus of intense research at SIMES and around the world because of their potential for creating “valleytronic” devices. In valleytronics, electrons move through a two-dimensional semiconductor as a wave with two energy valleys whose characteristics can be used to encode information. Possible applications include light detectors, low-energy computer logic and data storage chips and quantum computing. In addition to the work on graphene, members of the research team have also been simulating experiments involving the interaction of light with dichalcogenides.

    “Ultimately,” Moritz said, “we’re trying to understand how interaction with light can alter a material’s character and properties to create something that’s both new and interesting from a technological point of view.”

    In addition to SLAC, Stanford, SIMES and the Max Planck Institute for the Structure and Dynamics of Matter, other members of the research team were from Berkeley Lab, the University of Tokyo and Georgetown University. The work was funded by the DOE Office of Science.

    See the full article here.

    Please help promote STEM in your local schools.

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    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 11:06 am on May 6, 2015 Permalink | Reply
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    From SLAC: “Compact Light Source Improves CT Scans” 

    SLAC Lab

    May 5, 2015

    New Technology May Advance Preclinical Studies of Cancer and Other Diseases

    A new study shows that the recently developed Compact Light Source (CLS) – a commercial X-ray source with roots in research and development efforts at the Department of Energy’s SLAC National Accelerator Laboratory – enables computer tomography scans that reveal more detail than routine scans performed at hospitals today. The new technology could soon be used in preclinical studies and help researchers better understand cancer and other diseases.

    With its ability to image cross sections of the human body, X-ray computer tomography (CT) has become an important diagnostic tool in medicine. Conventional CT scans are very detailed when it comes to bones and other dense body parts that strongly absorb X-rays. However, the technique struggles with the visualization and distinction of “soft tissues” such as organs, which are more transparent to X-rays.

    “Our work demonstrates that we can achieve better results with the Compact Light Source,” says Professor for Biomedical Physics Franz Pfeiffer of the Technical University of Munich in Germany, who led the new study published April 20 in the Proceedings of the National Academy of Sciences. “The CLS allows us to do multimodal tomography scans – a more advanced approach to X-ray imaging.”

    More than One Kind of Contrast

    The amount of detail in a CT scan depends on the difference in brightness, or contrast, which makes one type of tissue distinguishable from another. The absorption of X-rays – the basis for standard CT – is only one way to create contrast.

    Alternatively, contrast can be generated from differences in how tissues change the direction of incoming X-rays, either through bending or scattering X-ray light. These techniques are known as phase-contrast and dark-field CT, respectively.

    “Organs and other soft tissues don’t have a large absorption contrast, but they become visible in phase-contrast tomography,” says the study’s lead author, Elena Eggl, a researcher at the Technical University of Munich. “The dark-field method, on the other hand, is particularly sensitive to structures like vertebrae and the lung’s alveoli.”

    The Compact Light Source by Palo Alto-based Lyncean Technologies Inc. generates X-rays suitable for advanced tomography. The car-sized device is a miniature version of football-field-sized X-ray generators known as synchrotrons and it emerged from basic research at SLAC in the late 1990s and early 2000s. (Lyncean Technologies Inc.)

    X-ray images of a variety of mammography test objects using absorption (left), phase-contrast (center) and dark-field (right) imaging modes. Different objects appear more clearly in one or another image, depending on the object’s properties. (Franz Pfeiffer/Technical University of Munich)

    Shrinking the Synchrotron

    However, these methods require X-ray light with a well-defined wavelength aligned in a particular way – properties that conventional CT scanners in hospitals do not deliver sufficiently.

    For high-quality phase-contrast and dark-field imaging, researchers can use synchrotrons – dedicated facilities where electrons run laps in football-stadium-sized storage rings to produce the desired radiation – but these are large and expensive machines that cannot simply be implemented at every research institute and clinic.

    Conversely, the CLS is a miniature version of a synchrotron that produces suitable X-rays by colliding laser light with electrons circulating in a desk-sized storage ring. Due to its small footprint and lower cost, it could be operated in almost any location.

    “The Large Hadron Collider at CERN is the world’s largest colliding beam storage ring, and the CLS is the smallest,” says SLAC scientist Ronald Ruth, one of the study’s co-authors. Ruth is also chairman of the board of directors and co-founder of Palo Alto-based Lyncean Technologies Inc., which developed the X-ray source based on earlier fundamental research at SLAC. “It turns out that the properties of the CLS are perfect for applications like tomography.”

    See the full article here.

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  • richardmitnick 8:53 pm on January 16, 2015 Permalink | Reply
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    From Symmetry: “20-ton magnet heads to New York” 


    January 16, 2015
    Justin Eure

    A superconducting magnet begins its journey from SLAC laboratory in California to Brookhaven Lab in New York.

    Imagine an MRI magnet with a central chamber spanning some 9 feet—massive enough to accommodate a standing African elephant. Physicists at the US Department of Energy’s Brookhaven National Laboratory need just such an extraordinary piece of equipment for an upcoming experiment. And, as luck would have it, physicists at SLAC National Accelerator Laboratory happen to have one on hand.

    Photo by Andy Freeberg, SLAC National Accelerator Laboratory

    Instead of looking at the world’s largest land animal, this magnet takes aim at the internal structure of something much smaller: the atomic nucleus.

    Researchers at Brookhaven’s Relativistic Heavy Ion Collider (RHIC) specialize in subatomic investigations, smashing atoms and tracking the showers of fast-flying debris. RHIC scientists have been sifting through collision data nuclei for 13 years, but to go even deeper they need to upgrade their detector technology. That’s where a massive cylindrical magnet comes in.


    “The technical difficulty in manufacturing such a magnet is staggering,” says Brookhaven Lab physicist David Morrison, co-spokesperson for PHENIX, one of RHIC’s two main experiments. “The technology may be similar to an MRI—also a superconducting solenoid with a hollow center—but many times larger and completely customized. These magnets look very simple from the outside, but the internal structure contains very sophisticated engineering. You can’t just order one of these beasts from a catalogue. ”

    BNL Phenix

    The proposed detector upgrade—called sPHENIX—launched the search for this elusive magnet. After assessing magnets at physics labs across the world, the PHENIX collaboration found an ideal candidate in storage across the country.

    At SLAC in California, a 40,000-pound beauty had recently finished a brilliant experimental run. This particular solenoid magnet—a thick, hollow pipe about 3.5 meters across and 3.9 meters long—once sat at the heart of a detector in SLAC’s BaBar experiment, which explored the asymmetry between matter and antimatter from 1999 to 2008.

    SLAC Babar
    SLAC Babar

    “We disassembled the detector and most of the parts have already gone to the scrap yard,” says Bill Wisniewski, who serves as the deputy to the SLAC Particle Physics and Astrophysics director and was closely involved with planning the move. “It’s just such a pleasure to see that there’s some hope that a major component of the detector—the solenoid—will be reused.”

    The magnet was loaded onto a truck and departed SLAC today, beginning its long and careful journey to Brookhaven’s campus in New York.

    “The particles that bind and constitute most of the visible matter in the universe remain quite mysterious,” says PHENIX co-spokesperson Jamie Nagle, a physicist at the University of Colorado. “We’ve made extraordinary strides at RHIC, but the BaBar magnet will take us even further. We’re grateful for this chance to give this one-of-a-kind equipment a second life, and I’m very excited to see how it shapes the future of nuclear physics.”

    The BaBar solenoid

    The BaBar magnet, a 30,865-pound solenoid housed in an 8250-pound frame, was built by the Italian company Ansaldo. Ansaldo’s superconducting magnets have found their way into many pioneering physics experiments, including the ATLAS and CMS detectors of the Large Hadron Collider. The inner ring of the BaBar magnet spans 2.8 meters with a total outer diameter of nearly 3.5 meters—nearly the width of the Statue of Liberty’s arm.


    CERN CMS New

    During its run at SLAC, the BaBar experiment made many strides in fundamental physics, including contributions to the work awarded the 2008 Nobel Prize in Physics for the theory behind “charge-parity violation,” the idea that matter and antimatter behave in slightly different ways. This concept explains in part why the universe today is filled with matter and not antimatter.

    “BaBar was a seminal experiment in particle physics, and the magnet’s strength, size and uniform field proved essential to its discoveries,” says John Haggerty, the Brookhaven physicist leading the acquisition of the BaBar magnet. “It’s a remarkable piece of engineering, and it has potential beyond its original purpose.”

    In May 2013, Haggerty visited SLAC to meet with Wesley Craddock, the engineer who worked with the magnet since its installation, and Mike Racine, the technician who supervised its removal and storage. “It was immediately clear that this excellent solenoid was in very good condition and almost ready to move,” Haggerty says.

    Adds Morrison, “The BaBar magnet is larger than our initial plans called for, but using this incredible instrument will save considerable resources by repurposing existing national lab assets.”

    Brookhaven Lab was granted ownership of the BaBar solenoid in July 2013, but there was still the issue of the entire continent that sat between SLAC and the experimental hall of the PHENIX detector.

    Photo by: Andy Freeberg, SLAC National Accelerator Laboratory

    The Department of Energy is no stranger to sharing massive magnets. In the summer of 2013, the 50-foot-wide Muon g-2 ring moved from Brookhaven Lab to Fermilab, where it will search for undiscovered particles hidden in the vacuum.

    “As you might imagine, shipping this magnet requires very careful consideration,” says Peter Wanderer, who heads Brookhaven’s Superconducting Magnet Division and worked with colleagues Michael Anerella and Paul Kovach on engineering for the big move. “You’re not only dealing with an oddly shaped and very heavy object, but also one that needs to be protected against even the slightest bit of damage. This kind of high-field, high-uniformity magnet can be surprisingly sensitive.”

    Preparations for the move required consulting with one of the solenoid’s original designers in Italy, Pasquale Fabbricatore, and designing special shipping fixtures to stabilize components of the magnet.

    After months of preparation at both SLAC and Brookhaven, the magnet—inside its custom packaging—was loaded onto a specialized truck this morning, and slowly began its journey to New York.

    “I’m sad to see it go,” Racine says. “It’s the only one like it in the world. But I’m happy to see it be reused.”

    After the magnet arrives, a team of experts will conduct mechanical, electrical, and cryogenic tests to prepare for its use in the upgrade to the sPHENIX upgrade.

    “We hope to have sPHENIX in action by 2021—including the BaBar magnet at its heart—but we have to remember that it is currently a proposal, and physics is full of surprises,” Morrison says.

    The BaBar magnet will be particularly helpful in identifying upsilons—the bound state of a very heavy bottom quark and an equally heavy anti-bottom quark. There are three closely related kinds of upsilons, each of which melts, or dissociates, at a different well-defined trillion-degree temperature. This happens in the state of matter known as quark-gluon plasma, or QGP, which was discovered at RHIC.

    “We can use these upsilons as a very precise thermometer for the QGP and understand its transition into normal matter,” Morrison says. “Something similar happened in the early universe as it began to cool microseconds after the big bang.”

    See the full article here.

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    Symmetry is a joint Fermilab/SLAC publication.

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