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  • richardmitnick 11:56 am on July 12, 2019 Permalink | Reply
    Tags: "Enriching solid-state batteries", , , Jennifer Rupp, Laser Technology, , , , ,   

    From MIT News: Women in STEM-“Enriching solid-state batteries” Jennifer Rupp 

    MIT News

    From MIT News

    July 11, 2019
    Denis Paiste | Materials Research Laboratory

    1
    MIT Associate Professor Jennifer Rupp stands in front of a pulsed laser deposition chamber, in which her team developed a new lithium garnet electrolyte material with the fastest reported ionic conductivity of its type. The technique produces a thin film about 330 nanometers thick. “Having the lithium electrolyte as a solid-state very fast conductor allows you to dream out loud of anything else you can do with fast lithium motion,” Rupp says. Photo: Denis Paiste/Materials Research Laboratory

    Researchers at MIT have come up with a new pulsed laser deposition technique to make thinner lithium electrolytes using less heat, promising faster charging and potentially higher-voltage solid-state lithium ion batteries.

    Key to the new technique for processing the solid-state battery electrolyte is alternating layers of the active electrolyte lithium garnet component (chemical formula, Li6.25Al0.25La3Zr2O12, or LLZO) with layers of lithium nitride (chemical formula Li3N). First, these layers are built up like a wafer cookie using a pulsed laser deposition process at about 300 degrees Celsius (572 degrees Fahrenheit). Then they are heated to 660 C and slowly cooled, a process known as annealing.

    During the annealing process, nearly all of the nitrogen atoms burn off into the atmosphere and the lithium atoms from the original nitride layers fuse into the lithium garnet, forming a single lithium-rich, ceramic thin film. The extra lithium content in the garnet film allows the material to retain the cubic structure needed for positively charged lithium ions (cations) to move quickly through the electrolyte. The findings were reported in a Nature Energy paper published online recently by MIT Associate Professor Jennifer L. M. Rupp and her students Reto Pfenninger, Michal M. Struzik, Inigo Garbayo, and collaborator Evelyn Stilp.

    “The really cool new thing is that we found a way to bring the lithium into the film at deposition by using lithium nitride as an internal lithiation source,” Rupp, the work’s senior author, says. Rupp holds joint MIT appointments in the departments of Materials Science and Engineering and Electrical Engineering and Computer Science.

    “The second trick to the story is that we use lithium nitride, which is close in bandgap to the laser that we use in the deposition, whereby we have a very fast transfer of the material, which is another key factor to not lose lithium to evaporation during a pulsed laser deposition,” Rupp explains.

    Safer technology

    Lithium batteries with commonly used electrolytes made by combining a liquid and a polymer can pose a fire risk when the liquid is exposed to air. Solid-state batteries are desirable because they replace the commonly used liquid polymer electrolytes in consumer lithium batteries with a solid material that is safer. “So we can kick that out, bring something safer in the battery, and decrease the electrolyte component in size by a factor of 100 by going from the polymer to the ceramic system,” Rupp explains.

    Although other methods to produce lithium-rich ceramic materials on larger pellets or tapes, heated using a process called sintering, can yield a dense microstructure that retains a high lithium concentration, they require higher heat and result in bulkier material. The new technique pioneered by Rupp and her students produces a thin film that is about 330 nanometers thick (less than 1.5 hundred-thousandths of an inch). “Having a thin film structure instead of a thick ceramic is attractive for battery electrolyte in general because it allows you to have more volume in the electrodes, where you want to have the active storage capacity. So the holy grail is be thin and be fast,” she says.

    Compared to the classic ceramic coffee mug, which under high magnification shows metal oxide particles with a grain size of tens to hundreds of microns, the lithium (garnet) oxide thin films processed using Rupp’s methods show nanometer scale grain structures that are one-thousandth to one-ten-thousandth the size. That means Rupp can engineer thinner electrolytes for batteries. “There is no need in a solid-state battery to have a large electrolyte,” she says.

    Faster ionic conduction

    Instead, what is needed is an electrolyte with faster conductivity. The unit of measurement for lithium ion conductivity is expressed in Siemens. The new multilayer deposition technique produces a lithium garnet (LLZO) material that shows the fastest ionic conductivity yet for a lithium-based electrolyte compound, about 2.9 x 10-5 Siemens (0.000029 Siemens) per centimeter. This ionic conductivity is competitive with solid-state lithium battery thin film electrolytes based on LIPON (lithium phosphorus oxynitride electrolytes) and adds a new film electrolyte material to the landscape.

    “Having the lithium electrolyte as a solid-state very fast conductor allows you to dream out loud of anything else you can do with fast lithium motion,” Rupp says.

    A battery’s negatively charged electrode stores power. The work points the way toward higher-voltage batteries based on lithium garnet electrolytes, both because its lower processing temperature opens the door to using materials for higher voltage cathodes that would be unstable at higher processing temperatures, and its smaller electrolyte size allows physically larger cathode volume in the same battery size.

    Co-authors Michal Struzik and Reto Pfenninger carried out processing and Raman spectroscopy measurements on the lithium garnet material. These measurements were key to showing the material’s fast conduction at room temperature, as well as understanding the evolution of its different structural phases.

    “One of the main challenges in understanding the development of the crystal structure in LLZO was to develop appropriate methodology. We have proposed a series of experiments to observe development of the crystal structure in the [LLZO] thin film from disordered or ‘amorphous’ phase to fully crystalline, highly conductive phase utilizing Raman spectroscopy upon thermal annealing under controlled atmospheric conditions,” says co-author Struzik, who was a postdoc working at ETH Zurich and MIT with Rupp’s group, and is now a professor at Warsaw University of Technology in Poland. “That allowed us to observe and understand how the crystal phases are developed and, as a consequence, the ionic conductivity improved,” he explains.

    Their work shows that during the annealing process, lithium garnet evolves from the amorphous phase in the initial multilayer processed at 300 C through progressively higher temperatures to a low conducting tetragonal phase in a temperature range from about 585 C to 630 C, and to the desired highly conducting cubic phase after annealing at 660 C. Notably, this temperature of 660 C to achieve the highly conducting phase in the multilayer approach is nearly 400 C lower than the 1,050 C needed to achieve it with prior sintering methods using pellets or tapes.

    “One of the greatest challenges facing the realization of solid-state batteries lies in the ability to fabricate such devices. It is tough to bring the manufacturing costs down to meet commercial targets that are competitive with today’s liquid-electrolyte-based lithium-ion batteries, and one of the main reasons is the need to use high temperatures to process the ceramic solid electrolytes,” says Professor Peter Bruce, the Wolfson Chair of the Department of Materials at Oxford University, who was not involved in this research.

    “This important paper reports a novel and imaginative approach to addressing this problem by reducing the processing temperature of garnet-based solid-state batteries by more than half — that is, by hundreds of degrees,” Bruce adds. “Normally, high temperatures are required to achieve sufficient solid-state diffusion to intermix the constituent atoms of ceramic electrolyte. By interleaving lithium layers in an elegant nanostructure the authors have overcome this barrier.”

    After demonstrating the novel processing and high conductivity of the lithium garnet electrode, the next step will be to test the material in an actual battery to explore how the material reacts with a battery cathode and how stable it is. “There is still a lot to come,” Rupp predicts.

    Understanding aluminum dopant sites

    A small fraction of aluminum is added to the lithium garnet formulation because aluminum is known to stabilize the highly conductive cubic phase in this high-temperature ceramic. The researchers complemented their Raman spectroscopy analysis with another technique, known as negative-ion time-of-flight secondary ion mass spectrometry (TOF-SIMS), which shows that the aluminum retains its position at what were originally the interfaces between the lithium nitride and lithium garnet layers before the heating step expelled the nitrogen and fused the material.

    “When you look at large-scale processing of pellets by sintering, then everywhere where you have a grain boundary, you will find close to it a higher concentration of aluminum. So we see a replica of that in our new processing, but on a smaller scale at the original interfaces,” Rupp says. “These little things are what adds up, also, not only to my excitement in engineering but my excitement as a scientist to understand phase formations, where that goes and what that does,” Rupp says.

    “Negative TOF-SIMS was indeed challenging to measure since it is more common in the field to perform this experiment with focus on positively charged ions,” explains Pfenninger, who worked at ETH Zurich and MIT with Rupp’s group. “However, for the case of the negatively charged nitrogen atoms we could only track it in this peculiar setup. The phase transformations in thin films of LLZO have so far not been investigated in temperature-dependent Raman spectroscopy — another insight towards the understanding thereof.”

    The paper’s other authors are Inigo Garbayo, who is now at CIC EnergiGUNE in Minano, Spain, and Evelyn Stilp, who was then with Empa, Swiss Federal Laboratories for Materials Science and Technology, in Dubendorf, Switzerland.

    Rupp began this research while serving as a professor of electrochemical materials at ETH Zurich (the Swiss Federal Institute of Technology) before she joined the MIT faculty in February 2017. MIT and ETH have jointly filed for two patents on the multi-layer lithium garnet/lithium nitride processing. This new processing method, which allows precise control of lithium concentration in the material, can also be applied to other lithium oxide films such as lithium titanate and lithium cobaltate that are used in battery electrodes. “That is something we invented. That’s new in ceramic processing,” Rupp says.

    “It is a smart idea to use Li3N as a lithium source during preparation of the garnet layers, as lithium loss is a critical issue during thin film preparation otherwise,” comments University Professor Jürgen Janek at Justus Liebig University Giessen in Germany. Janek, who was not involved in this research, adds that “the quality of the data and the analysis is convincing.”

    “This work is an exciting first step in preparing one of the best oxide-based solid electrolytes in an intermediate temperature range,” Janek says. “It will be interesting to see whether the intermediate temperature of about 600 degrees C is sufficient to avoid side reactions with the electrode materials.”

    Oxford Professor Bruce notes the novelty of the approach, adding “I’m not aware of similar nanostructured approaches to reduce diffusion lengths in solid-state synthesis.”

    “Although the paper describes specific application of the approach to the formation of lithium-rich and therefore highly conducting garnet solid electrolytes, the methodology has more general applicability, and therefore significant potential beyond the specific examples provided in the paper,” Bruce says. Commercialization may be needed to be demonstrate this approach at larger scale, he suggests.

    While the immediate impact of this work is likely to be on batteries, Rupp predicts another decade of exciting advances based on applications of her processing techniques to devices for neuromorphic computing, artificial intelligence, and fast gas sensors. “The moment the lithium is in a small solid-state film, you can use the fast motion to trigger other electrochemistry,” she says.

    Several companies have already expressed interest in using the new electrolyte approach. “It’s good for me to work with strong players in the field so they can push out the technology faster than anything I can do,” Rupp says.

    This work was funded by the MIT Lincoln Laboratory, the Thomas Lord Foundation, Competence Center Energy and Mobility, and Swiss Electrics.

    See the full article here .


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  • richardmitnick 10:42 am on June 15, 2019 Permalink | Reply
    Tags: A tale of two liquids, , , , Laser Technology, , , When stable becomes unstable,   

    From SLAC National Accelerator Lab: “A quick liquid flip helps explain how morphing materials store information” 

    From SLAC National Accelerator Lab

    June 14, 2019

    Experiments at SLAC’s X-ray laser reveal in atomic detail how two distinct liquid phases in these materials enable fast switching between glassy and crystalline states that represent 0s and 1s in memory devices.

    1
    In phase-change memory devices, a material switches between glassy and crystalline phases that represent the 0s and 1s used to store information. One pulse of electricity or light heats the material to high temperature, causing it to crystallize, and another pulse melts it into a disordered, glassy state. Experiments at SLAC’s X-ray laser revealed a key part of this switch – a quick transition from one liquid-like state to another – that enables fast and reliable data storage. (Peter Zalden/European XFEL)

    Instead of flash drives, the latest generation of smart phones uses materials that change physical states, or phases, to store and retrieve data faster, in less space and with more energy efficiency. When hit with a pulse of electricity or optical light, these materials switch between glassy and crystalline states that represent the 0s and 1s of the binary code used to store information.

    Now scientists have discovered how those phase changes occur on an atomic level.

    Researchers from European XFEL and the University of Duisburg-Essen in Germany, working in collaboration with researchers at the Department of Energy’s SLAC National Accelerator Laboratory, led X-ray laser experiments at SLAC that collected more than 10,000 snapshots of phase-change materials transforming from a glassy to a crystalline state in real time.

    They discovered that just before the material crystallizes, it changes from one liquid-like state to another, a process that could not be clearly seen in prior studies because it was blurred by the rapid motions of the atoms. And they showed that this transition is responsible for the material’s unique ability to store information for long periods of time while also quickly switching between states.

    The results, published in Science today, offer a new strategy for designing improved phase-change materials for specialized memory storage.

    “Current data storage technology has reached a scaling limit, so that new concepts are required to store the amounts of data that we will produce in the future,” said Peter Zalden, a scientist at European XFEL and lead author of the study. “Our study explains how the switching process in a promising new technology can be fast and reliable at the same time.”

    When stable becomes unstable

    The experiments took place at SLAC’s Linac Coherent Light Source (LCLS) which produces X-ray laser pulses that are short enough and intense enough to capture snapshots of atomic changes occurring in femtoseconds – millionths of a billionths of a second.

    To store information with phase-change materials, they must be cooled quickly to enter a glassy state without crystallizing, and remain in this glassy state as long as the information needs to stay there. This means the crystallization process must be very slow to the point of being almost absent, such as is the case in ordinary glass. But when it comes time to erase the information, which is done by applying high temperatures, the same material has to crystallize very quickly. The fact that a material can form a stable glass but then become very unstable at elevated temperatures has puzzled researchers for decades.

    At LCLS, the scientists used an optical laser to rapidly heat amorphous films of phase-change materials, just 50 nanometers thick, atop an equally thin support. The films cooled into a crystalline state as the heat from the laser blast dissipated into the surrounding support structure over billionths of a second.

    They used X-ray laser pulses to make images of the material’s structural evolution, collecting each snapshot in the instant before a sample deteriorated.

    A tale of two liquids

    The researchers found that when the liquid cools far enough below the material’s melting temperature, it undergoes a structural change to form another, lower-temperature liquid that exists for just billionths of a second.

    The two liquids not only have very different atomic structures, but they also behave differently: The one at higher temperature has highly mobile atoms that can quickly arrange themselves into the well-ordered structure of a crystal. But in the lower-temperature liquid, some chemical bonds become stronger and more rigid and can hold the disordered atomic structure of the glass in place. It is only the rigid nature of these chemical bonds that keeps the glass from crystallizing and – in the case of phase-change memory devices – secures information in place. The results also help scientists understand how other classes of materials form a glass.

    2
    The research team after performing experiments at SLAC’s Linac Coherent Light Source X-ray laser. (Klaus Sokolowski-Tinten/University of Duisburg-Essen)

    See the full article here.
    See the XFEL press release here .


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    SLAC/LCLS


    SLAC/LCLS II projected view


    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 12:24 pm on June 13, 2019 Permalink | Reply
    Tags: , , , Compact particle accelerators, , Laser Technology   

    From DESY: “Laser trick produces high-energy terahertz pulses” 

    DESY
    From DESY

    2019/06/13

    Milestone for compact particle accelerators.

    A team of scientists from DESY and the University of Hamburg has achieved an important milestone in the quest for a new type of compact particle accelerator. Using ultra-powerful pulses of laser light, they were able to produce particularly high-energy flashes of radiation in the terahertz range having a sharply defined wavelength (colour). Terahertz radiation is to open the way for a new generation of compact particle accelerators that will find room on a lab bench. The team headed by Andreas Maier and Franz Kärtner from the Hamburg Center for Free-Electron Laser Science (CFEL) is presenting its findings in the journal Nature Communications. CFEL is jointly run by DESY, the University of Hamburg and the Max Planck Society.

    1
    From the colour difference of two slightly delayed laser flashes (left) a non-linear crystal generates an energetic terahertz pulse (right). Credit: DESY, Lucid Berlin

    The terahertz range of electromagnetic radiation lies between the infrared and microwave frequencies. Air travellers may be familiar with terahertz radiation from the full-body scanners used by airport security to search for objects hidden beneath a person’s garments. However, radiation in this frequency range might also be used to build compact particle accelerators. “The wavelength of terahertz radiation is about a thousand times shorter than the radio waves that are currently used to accelerate particles,” says Kärtner, who is a lead scientist at DESY. “This means that the components of the accelerator can also be built to be around a thousand times smaller.” The generation of high-energy terahertz pulses is therefore also an important step for the AXSIS (frontiers in Attosecond X-ray Science: Imaging and Spectroscopy) project at CFEL, funded by the European Research Council (ERC), which aims to open up completely new applications with compact terahertz particle accelerators.

    However, chivvying along an appreciable number of particles calls for powerful pulses of terahertz radiation having a sharply defined wavelength. This is precisely what the team has now managed to create. “In order to generate terahertz pulses, we fire two powerful pulses of laser light into a so-called non-linear crystal, with a minimal time delay between the two,” explains Maier from the University of Hamburg. The two laser pulses have a kind of colour gradient, meaning that the colour at the front of the pulse is different from that at the back. The slight time shift between the two pulses therefore leads to a slight difference in colour. “This difference lies precisely in the terahertz range,” says Maier. “The crystal converts the difference in colour into a terahertz pulse.”

    The method requires the two laser pulses to be precisely synchronised. The scientists achieve this by splitting a single pulse into two parts and sending one of them on a short detour so that it is slightly delayed before the two pulses are eventually superimposed again. However, the colour gradient along the pulses is not constant, in other words the colour does not change uniformly along the length of the pulse. Instead, the colour changes slowly at first, and then more and more quickly, producing a curved outline. As a result, the colour difference between the two staggered pulses is not constant. The difference is only appropriate for producing terahertz radiation over a narrow stretch of the pulse.

    That was a big obstacle towards creating high-energy terahertz pulses,” as Maier reports. “Because straightening the colour gradient of the pulses, which would have been the obvious solution, is not easy to do in practice.” It was co-author Nicholas Matlis who came up with the crucial idea: he suggested that the colour profile of just one of the two partial pulses should be stretched slightly along the time axis. While this still does not alter the degree with which the colour changes along the pulse, the colour difference with respect to the other partial pulse now remains constant at all times. “The changes that need to be made to one of the pulses are minimal and surprisingly easy to achieve: all that was necessary was to insert a short length of a special glass into the beam,” reports Maier. “All of a sudden, the terahertz signal became stronger by a factor of 13.” In addition, the scientists used a particularly large non-linear crystal to produce the terahertz radiation, specially made for them by the Japanese Institute for Molecular Science in Okazaki.

    “By combining these two measures, we were able to produce terahertz pulses with an energy of 0.6 millijoules, which is a record for this technique and more than ten times higher than any terahertz pulse of sharply defined wavelength that has previously been generated by optical means,” says Kärtner. “Our work demonstrates that it is possible to produce sufficiently powerful terahertz pulses with sharply defined wavelengths in order to operate compact particle accelerators.”

    See the full article here .


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    desi

    DESY is one of the world’s leading accelerator centres. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety – from the interactions of tiny elementary particles and the behaviour of new types of nanomaterials to biomolecular processes that are essential to life. The accelerators and detectors that DESY develops and builds are unique research tools. The facilities generate the world’s most intense X-ray light, accelerate particles to record energies and open completely new windows onto the universe. 
That makes DESY not only a magnet for more than 3000 guest researchers from over 40 countries every year, but also a coveted partner for national and international cooperations. Committed young researchers find an exciting interdisciplinary setting at DESY. The research centre offers specialized training for a large number of professions. DESY cooperates with industry and business to promote new technologies that will benefit society and encourage innovations. This also benefits the metropolitan regions of the two DESY locations, Hamburg and Zeuthen near Berlin.

    DESY Petra III interior


    DESY Petra III

    DESY/FLASH

    H1 detector at DESY HERA ring

    DESY DORIS III

     
  • richardmitnick 9:51 am on June 11, 2019 Permalink | Reply
    Tags: "Seeing the Light", , , , , , Laser Technology, Lunar research   

    From Eos: “Seeing the Light” 

    From AGU
    Eos news bloc

    From Eos

    6.11.19
    Damond Benningfield

    1
    Apache Point Observatory’s laser fires at the Apollo 15 retroreflector during a lunar eclipse in 2014. Credit: Dan Long, Apache Point Observatory

    Apache Point Observatory, near Sunspot, New Mexico Altitude 2,788 meters (9,147 ft)

    When Neil Armstrong and Edwin “Buzz” Aldrin blasted off the Moon on 21 July 1969, they left a couple of packages at Tranquility Base. One was a solar-powered seismometer that collected 21 days of observations before expiring in late August. The other was an aluminum frame filled with chunks of fused-silica glass that looked a bit like a high-tech egg crate.

    Along with similar devices left on the Moon by Apollo 14 and 15, the instrument is still working—the only Apollo surface experiment that continues to provide data.

    Known as a lunar laser ranging retroreflector, it bounces pulses of laser light back to their sources on Earth. Scientists time the round-trip travel time of each pulse, allowing them to measure the Earth-Moon distance to within a millimeter. A half century of these observations has provided precise measurements of the shape of the Moon’s orbit, wobbles in the Moon’s rotation, and other parameters. Those, in turn, have helped scientists determine the Moon’s recession rate, probe its interior structure, and test gravitational theory to some of the highest levels of precision yet obtained.

    “This is a venerable technique that’s provided some of our best science about how gravity works,” says Tom Murphy, a professor of physics at the University of California, San Diego, who has headed a lunar laser-ranging project since the early 2000s.

    Peculiar Prisms on the Moon

    The devices left on the Moon by Apollo astronauts (as well as two others aboard Soviet Lunokhod rovers) consist of arrays of corner cube reflectors.

    2
    McDonald Observatory’s 2.7-meter telescope beams a laser toward the Moon. The telescope, part of the University of Texas at Austin, conducted laser observations from 1969 to the mid-1980s, when laser ranging was moved to a smaller telescope. Credit: Frank Armstrong/UT Austin

    U Texas at Austin McDonald Observatory, Altitude 2,070 m (6,790 ft)

    “These are like peculiar prisms—they’re shaped like the upper corner of a room,” says Doug Currie, a professor of physics at the University of Maryland in College Park who has worked in the field since the 1960s. “You could throw a tennis ball in the corner, and it would hit all three sides and bounce back to you. The lunar reflectors do the same thing. The difference is, you can send up to 1023 photons at a time, and you’re happy when one comes back.”

    The Apollo 11 and 14 retroreflectors each contain one hundred 3.8-centimeter corner cubes, whereas the Apollo 15 array contains 300, so it produces the strongest return signal.

    Photons are beamed toward the Moon through a telescope, such as the 3.5-meter telescope at Apache Point Observatory in New Mexico, the largest instrument ever to conduct lunar laser ranging. The laser is fired in 100-picosecond pulses—“bullets of light” just 2 centimeters thick, says Murphy, who heads the Apache Point Observatory Lunar Laser-ranging Operation (APOLLO).

    No more than a few photons from each pulse return to the telescope, but the telescope fires thousands of laser bullets during each ranging session, allowing it to collect thousands of photons per session. Statistical analysis smooths out the differences in ranges between individual photons, producing a distance to the Moon with an accuracy of about 1 millimeter.

    APOLLO ranges to the Moon about six times per month and targets all five of the retroreflectors during each session. France’s Observatoire de la Côte d’Azur, the other major lunar-ranging station, uses a smaller telescope but has begun ranging with an infrared laser, which is about 8 times more efficient than the standard green laser.

    An Array of Scientific Contributions

    3
    All five of the current lunar retroreflectors are located near or north of the Moon’s equator, leaving the southern hemisphere uncovered. Credit: NASA

    Lunar laser ranging’s first scientific contribution was to produce an accurate measurement of how quickly the Moon is moving away from Earth: 3.8 centimeters per year. The retreat is the result of the ocean tides on Earth, which cause our planet’s rotation rate to slowly increase. To balance the books on the overall motion of the Earth-Moon system, the Moon speeds up, causing it to move away from Earth.

    Collecting data from the network of five retroreflectors over the course of several decades also has allowed planetary scientists to probe the Moon’s interior by measuring how the Moon “wobbles” on its axis.

    Some of those wobbles are caused by the Moon’s elliptical orbit, but others are produced by motions within the Moon itself. Measurements of that interior “sloshing” revealed that the Moon has a liquid outer core that’s about 700 kilometers in diameter, roughly 20% of the Moon’s overall diameter.

    “Everybody came in thinking, ‘we really know the Moon,’ but we didn’t,” says Peter Shelus, a research scientist at the University of Texas at Austin, which conducted lunar laser-ranging operations for more than 40 years. “We didn’t know the lunar rotation as well as we thought. As we got more data, though, everything fell into place, and the rotation rate allowed us to probe the interior.”

    When the lunar laser-ranging experiment was conceived in the early 1960s, however, learning about the Moon itself was a secondary goal. The primary goal was to study gravity. And so far, laser ranging has confirmed Isaac Newton’s gravitational constant to the highest precision yet seen and confirmed other tenets of gravitational theory, including the equivalence principle, which says that gravitational energy should behave like other forms of energy and mass.

    “What we’re after, the flagship science, is the strong equivalence principle,” says Murphy. “By, quote, dropping Earth and the Moon toward the Sun, we can use the Earth-Moon separation as a way to explore whether two bodies are pulled toward the Sun differently. That’s a foundational tenet of general relativity, and it would be very important if we saw a violation there.”

    So far, the lunar laser-ranging experiment has confirmed relativity’s predictions about the equivalence principle to the highest precision yet seen—within the experiment’s margin of error, Earth and the Moon “fall” toward the Sun at the same rate.

    “There’s Still Work to Do”

    Despite the experiment’s success, Murphy says he’s “disappointed” in the results to date.

    “We’ve managed to produce measurements we’re all confident in at the millimeter level of accuracy, but the model that it takes to extract science from this result has been slow to catch up. So we haven’t yet seen the order-of-magnitude level of improvement that we hoped for in those tests. We’ve seen maybe a factor-of-2 level of improvement, but that’s not very satisfying.”

    James Williams, a senior research scientist at NASA’s Jet Propulsion Laboratory and another pioneer in the lunar-ranging field, agrees that there’s work to do to improve our understanding of the results.

    “We’ve measured the Earth-Moon acceleration toward the Sun to 1.5 parts in 1013, which is a very, very sensitive test. It limits certain gravitational theories,” Williams says. “But there’s stuff in the model and in the data that we still don’t understand. There’s still work to do.”

    While the models catch up, the observational side of the project could stand some improvement as well, scientists say.

    The Lunokhod reflectors, for example, can be used only around sunrise and sunset; thermal problems scuttle observations at other points in the lunar cycle. The Apollo reflectors are degrading, probably because micrometeorite impacts on the surface are splashing dust onto the corner cubes. All of the current retroreflectors are placed near or north of the equator, leaving the southern half of the lunar globe uncovered. And current ranging is so precise that the orientation of the retroreflectors can cause a problem: As the laser bounces off opposite corners of an array, it can increase uncertainty in the measurements by a few centimeters.

    Currie has proposed sending new reflectors to the Moon using a new corner cube design.

    “We’ve been working on a 100-millimeter glass reflector that’s basically a scaled-up version of the Apollo reflectors,” he says. “You don’t have to worry whether a returned photon came from the near corner or the far corner of an array. We think that’ll improve the accuracy of a shot by a factor of a hundred. We’ve had to solve some thermal issues with the reflectors and the frame, but we can put together a package that can fly.”

    Currie’s group has submitted proposals to NASA to strap one of the new modules on an upcoming lunar mission and has signed an agreement with Moon Express, a company vying to launch a lander.

    “If you’re going to the Moon, these are almost no-brainer accompaniments,” says Murphy. “Their success is almost guaranteed; they require no power, they’ll work for decades and decades….It’s a low-cost, high-reward investment, which is why it was included on the initial Apollo mission.”

    It’s an investment that’s still paying dividends 50 years later.

    See the full article here .

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    Eos is the leading source for trustworthy news and perspectives about the Earth and space sciences and their impact. Its namesake is Eos, the Greek goddess of the dawn, who represents the light shed on understanding our planet and its environment in space by the Earth and space sciences.

     
  • richardmitnick 9:14 am on June 4, 2019 Permalink | Reply
    Tags: "For The First Time Physicists Have Produced a Stunning Type of Plasma Jet in The Lab", Laser Technology, ,   

    From Rice University via From Science Alert: “For The First Time, Physicists Have Produced a Stunning Type of Plasma Jet in The Lab” 

    Rice U bloc

    From Rice University

    via

    ScienceAlert

    From Science Alert

    4 JUN 2019
    DAVID NIELD

    1
    OMEGA laser. (Rather Anonymous/Flickr/CC BY NC 2.0)

    Plasma, that super-hot mix of electrified atomic particles, plays a key role in the evolution of stars, black holes, and other cosmic elements. For closer study though, plasma needs to be recreated in a lab – and researchers have just managed to generate a particular type of plasma jet for the first time.

    The key characteristics of this lab-created plasma jet are its stability and its magnetism. Further study of the jet could help us unlock some more of the secrets of the Universe.

    Not only that, the scientists were able to run some advanced diagnostics on the jet – getting readings for its density, temperature, length, coherence, and magnetic field – which helps them better compare it to plasma out in space.

    “We are now creating stable, supersonic, and strongly magnetised plasma jets in a laboratory that might allow us to study astrophysical objects light years away,” says one of the team leaders, astrophysicist Edison Liang from Rice University in Texas.

    The researchers trained 20 individual laser beams into a circular shape on a plastic target to produce puffs of plasma, which were then pressurised as they expanded to create a plasma jet four millimetres (0.16 inches) in length, with a magnetic field strength of over 100 tesla (about 10,000 times stronger than a small bar magnet).

    Those original laser beams weren’t any ordinary lights, though – they were produced by the OMEGA laser at the Laboratory for Laser Energetics, part of the University of Rochester in New York. It’s one of the most powerful lasers in the world, capable of focussing huge energy bursts on very small targets.

    U Rochester OMEGA EP Laser System


    U Rochester Omega Laser

    Thanks to the diagnostic work the researchers carried out on the plasma jet, they now have a baseline to use to see how the plasma reacts under different conditions.

    Future tests will involve different types of plasma-related phenomena, such as using an external magnetic field to see if the jet grows in size and becomes more collimated (with parallel rays).

    The researchers also want to try the same experiment with the National Ignition Facility at Lawrence Livermore National Laboratory, which has no fewer than 192 laser beams – half of those could contribute to the plasma laser ring.

    “It would have a larger radius and thus produce a longer jet than that produced using OMEGA,” says one of the lead researchers, physicist Lan Gao from the Princeton Plasma Physics Laboratory (PPPL). “This process would help us figure out under which conditions the plasma jet is strongest.”

    The circle method the researchers developed here has the potential to scale up very well, the researchers say, and is similar to the plasma offshoots that might be observed from a newborn star – only easier to study up close.

    As the research continues, we should learn more about this special state of matter and the role it plays in the wider cosmos (as well as any ordinary microwave, if the right conditions are met).

    “This is groundbreaking research because no other team has successfully launched a supersonic, narrowly beamed jet that carries such a strong magnetic field, extending to significant distances,” says Liang.

    “This is the first time that scientists have demonstrated that the magnetic field does not just wrap around the jet, but also extends parallel to the jet’s axis.”

    The research has been published in The Astrophysical Journal Letters.

    See the full article here .


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


    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 7:42 am on June 4, 2019 Permalink | Reply
    Tags: , , Laser Technology, , , Supercritical drying,   

    From Lawrence Livermore National Laboratory: “Making metal with the lightness of air” 

    From Lawrence Livermore National Laboratory

    June 3, 2019
    Breanna Bishop
    bishop33@llnl.gov
    925-423-9802

    1
    A mosquito standing on cotton fibers carries a sample of ultra-low density gold aerogel. Photos by Joshua DeOtte.

    Gold, silver and copper are heavy metals, but LLNL scientists can now make them nearly as light as air — in a form so tiny it can ride on a mosquito’s back.

    The groundbreaking science, part of a joint NIF/Physical and Life Sciences (PLS) project supported by the Laboratory Directed Research and Development (LDRD) Program, created these ultra-low density metal foams to give physicists better X-ray sources to employ in experiments that support NIF’s Stockpile Stewardship mission.

    The foam is the product of a nearly decade-long research effort by members of the Lab’s NIF and PLS directorates for use on inertial confinement fusion (ICF) experiments at NIF, the world’s most energetic laser system.

    “We are looking primarily at fundamental science questions that govern how to synthesize, assemble and shape metal nanowire-based aerogels,” said materials scientist Michael Bagge-Hansen, the LDRD project’s principal investigator.

    The material is called foam because that’s historically what these types of materials were named, but it’s not a material made by foaming. It’s a spaghetti-like web of randomly connected nanometer-sized wires, formed into the shape of a miniature marshmallow and containing the same or fewer number of atoms as air.

    Physicist Sergei Kucheyev calls it a “porous metal monolith. There’s a lot going on here in terms of both chemistry and physics.”

    X-ray sources

    Scientists sought different ultra-low density metals that can be used as targets for laser-driven X-ray sources for experiments further probing the properties of various materials placed under the extreme conditions possible when NIF’s 192 high-powered lasers [see below] are directed inside the target chamber, said Tyler Fears, a staff scientist with the LLNL’s Materials Science Division (MSD).

    Each element emits a characteristic set of X-rays when heated by lasers into a plasma, Fears explained. Metal foams can mimic gas even though they are made from materials that are not gas at room temperature.

    The underlying physics of laser-driven X-ray sources, however, sets the bar high with rigorous specifications for the types, densities, shapes and sizes of metal foams needed for experiments.

    “We need heavy metal targets to be around the density of air and a few millimeters in size within well-defined dimensions,” he said. “Our challenge is to try to meet all those goals at the same time.”

    The team also had to make sure the techniques they developed could be repeated to consistently produce the foams, even if the size, shape and composition are changed to meet future experimental needs.

    2
    An ultra-low density metal foam sample dangles from a single strand of a spider’s web.

    “You need to be able to make either the same material or a comparable material every time,” Fears said. “We have to understand when we change something, how is that going to change the product? If you change the density or if you change the shape, you have to know that’s the only thing you’re changing.”

    Kucheyev said the research dates back nearly a decade, but “only in the last couple of years did we get foams of this amazing quality.”

    Some previous versions aged in air before they could be brought into the target chamber, when they “ended up looking like old stale marshmallows,” he said. Another iteration came out of molds looking distorted, while others fell apart so easily one team member called them “cigarette ash.”

    The team also tried using other types of low-density material to create scaffolding that provided a supporting structure for embedded particles of the specific metals. But the scaffolding materials would create unwanted X rays when hit by lasers, which would interfere with the X-ray data scientists wanted from the specific types of foam they were testing.

    So, to maintain the purity of the X-ray spectrum, the team had to create the wire structure out of the specific metal itself, which was “the biggest challenge we had,” said materials scientist Fang Qian.

    “The dearth of previous literature on creating these types of wires in large amounts meant we had to perform numerous experiments and fundamental studies to understand the synthetic mechanisms,” she said. “We also have leveraged several characterization tools in MSD to evaluate growth models, structure, surface and chemistry of these unique materials. We eventually developed our own unique recipe and protocol.”

    Qian added that MSD “can now rapidly perform the on-site research and development of metallic nanomaterials, such as particles and wires, and reproduce feedstocks at the gram-scale using rigorously tested procedures.”

    Supercritical drying

    The team freezes the nanowire inside a shape-creating mold typically filled with a water-glycerol mix. When it hardens, the nanowire looks like a “randomly interconnected mesh of frozen spaghetti,” Kucheyev said.

    The material is then removed from the mold and the frozen water is extracted by replacing it with the solvent acetone, which is then dissolved in a supercritical drying process using liquid carbon dioxide, leaving only the metal and air. Supercritical drying ensures the liquid transforms into a gas phase without creating a meniscus that could damage the fragile ultra-low density metal foam structure.

    “You don’t have any capillary pressures and that also allows you to maintain the very small pores without any shrinkage,” Fears said.

    The team has produced copper and silver foam, and silver has performed well in NIF shots. The team is able to produce gold foams, which still tend to fall off the mounts that hold them in front of NIF’s lasers. “That’s the challenge we’re trying to overcome now,” Fears said.

    The joint PLS/NIF-funded LDRD project is designed to build on the team’s previous work with silver and copper so materials scientists can make ultra-low density metallic foams with other metals “to respond to current and future needs,” Bagge-Hansen said. The team is now working on tin as well as gold.

    “Translating these successes into other materials (e.g., gold) raised significant technical challenges that we are navigating in the LDRD,” he said. “I attribute our success to an innovative, diverse team of scientists that share their varied technical backgrounds to solve a highly multi-disciplinary challenge.”

    The effort also included Mark May, Brent Blue, Alyssa Troksa, Tom Braun, Thomas Yong-Jin Han, Ted Baumann, Daniel Malone, Corie Horwood, Chantel Aracne-Ruddle, Kelly Youngblood, Michael Stadermann and Suhas Bhandarkar.

    The foams were developed specifically for NIF as X-ray sources. The material also could be applied to other uses, however, such as target shells or hohlraum liners. And now that scientists know the material can be made, it could spur creative ideas for future experiments.

    The foams were developed specifically for NIF as X-ray sources. The material also could be applied to other uses, however, such as target shells or hohlraum liners. And now that scientists know the material can be made, it could spur creative ideas for future experiments.

    “The physicists come up with ideas, but usually they’ll ask what someone can make, and they’ll design an experiment around that,” Fears said. “If we can make a material that they never thought we could make before, they’ll come up with new experiments to fit those capabilities.”

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    LLNL Campus

    Operated by Lawrence Livermore National Security, LLC, for the Department of Energy’s National Nuclear Security Administration
    Lawrence Livermore National Laboratory (LLNL) is an American federal research facility in Livermore, California, United States, founded by the University of California, Berkeley in 1952. A Federally Funded Research and Development Center (FFRDC), it is primarily funded by the U.S. Department of Energy (DOE) and managed and operated by Lawrence Livermore National Security, LLC (LLNS), a partnership of the University of California, Bechtel, BWX Technologies, AECOM, and Battelle Memorial Institute in affiliation with the Texas A&M University System. In 2012, the laboratory had the synthetic chemical element livermorium named after it.
    LLNL is self-described as “a premier research and development institution for science and technology applied to national security.” Its principal responsibility is ensuring the safety, security and reliability of the nation’s nuclear weapons through the application of advanced science, engineering and technology. The Laboratory also applies its special expertise and multidisciplinary capabilities to preventing the proliferation and use of weapons of mass destruction, bolstering homeland security and solving other nationally important problems, including energy and environmental security, basic science and economic competitiveness.

    The Laboratory is located on a one-square-mile (2.6 km2) site at the eastern edge of Livermore. It also operates a 7,000 acres (28 km2) remote experimental test site, called Site 300, situated about 15 miles (24 km) southeast of the main lab site. LLNL has an annual budget of about $1.5 billion and a staff of roughly 5,800 employees.

    LLNL was established in 1952 as the University of California Radiation Laboratory at Livermore, an offshoot of the existing UC Radiation Laboratory at Berkeley. It was intended to spur innovation and provide competition to the nuclear weapon design laboratory at Los Alamos in New Mexico, home of the Manhattan Project that developed the first atomic weapons. Edward Teller and Ernest Lawrence,[2] director of the Radiation Laboratory at Berkeley, are regarded as the co-founders of the Livermore facility.

    The new laboratory was sited at a former naval air station of World War II. It was already home to several UC Radiation Laboratory projects that were too large for its location in the Berkeley Hills above the UC campus, including one of the first experiments in the magnetic approach to confined thermonuclear reactions (i.e. fusion). About half an hour southeast of Berkeley, the Livermore site provided much greater security for classified projects than an urban university campus.

    Lawrence tapped 32-year-old Herbert York, a former graduate student of his, to run Livermore. Under York, the Lab had four main programs: Project Sherwood (the magnetic-fusion program), Project Whitney (the weapons-design program), diagnostic weapon experiments (both for the Los Alamos and Livermore laboratories), and a basic physics program. York and the new lab embraced the Lawrence “big science” approach, tackling challenging projects with physicists, chemists, engineers, and computational scientists working together in multidisciplinary teams. Lawrence died in August 1958 and shortly after, the university’s board of regents named both laboratories for him, as the Lawrence Radiation Laboratory.

    Historically, the Berkeley and Livermore laboratories have had very close relationships on research projects, business operations, and staff. The Livermore Lab was established initially as a branch of the Berkeley laboratory. The Livermore lab was not officially severed administratively from the Berkeley lab until 1971. To this day, in official planning documents and records, Lawrence Berkeley National Laboratory is designated as Site 100, Lawrence Livermore National Lab as Site 200, and LLNL’s remote test location as Site 300.[3]

    The laboratory was renamed Lawrence Livermore Laboratory (LLL) in 1971. On October 1, 2007 LLNS assumed management of LLNL from the University of California, which had exclusively managed and operated the Laboratory since its inception 55 years before. The laboratory was honored in 2012 by having the synthetic chemical element livermorium named after it. The LLNS takeover of the laboratory has been controversial. In May 2013, an Alameda County jury awarded over $2.7 million to five former laboratory employees who were among 430 employees LLNS laid off during 2008.[4] The jury found that LLNS breached a contractual obligation to terminate the employees only for “reasonable cause.”[5] The five plaintiffs also have pending age discrimination claims against LLNS, which will be heard by a different jury in a separate trial.[6] There are 125 co-plaintiffs awaiting trial on similar claims against LLNS.[7] The May 2008 layoff was the first layoff at the laboratory in nearly 40 years.[6]

    On March 14, 2011, the City of Livermore officially expanded the city’s boundaries to annex LLNL and move it within the city limits. The unanimous vote by the Livermore city council expanded Livermore’s southeastern boundaries to cover 15 land parcels covering 1,057 acres (4.28 km2) that comprise the LLNL site. The site was formerly an unincorporated area of Alameda County. The LLNL campus continues to be owned by the federal government.

    LLNL/NIF


    DOE Seal
    NNSA

     
  • richardmitnick 7:43 am on May 21, 2019 Permalink | Reply
    Tags: Advanced Radiographic Capability (ARC), , , Laser Technology, , ,   

    From Lawrence Livermore National Laboratory: “ARC experiments exceed expectations” 

    From Lawrence Livermore National Laboratory

    May 17, 2019
    Breanna Bishop
    bishop33@llnl.gov
    925-423-9802

    – Charlie Osolin

    1
    At left: A schematic of the National Ignition Facility’s (NIF) target chamber with 192 NIF long-pulse beams shown in blue and two of the NIF beams “picked off” for ARC shown in red (upper right). The two long-pulse beams are split to form two rectangular beamlets each, giving a total of four beamlets that are compressed to picosecond-pulse lengths. Lower right: The modeled ellipsoidal focal spot for one of the four beamlets at target chamber center.

    The first proton-acceleration experiments using the National Ignition Facility’s (NIF) Advanced Radiographic Capability (ARC) short-pulse laser have produced protons with energies about 10 times higher than previous experience would have predicted (see “A Powerful New Source of High-Energy Protons”).

    Beams of high-energy protons can be precisely targeted and are able to quickly heat materials before they can expand. Ultrafast heating of matter will enable opacity and equation-of-state measurements at unprecedented energy densities and could open the door to new ways of studying extreme states of matter, such as stellar and planetary interiors. Proton acceleration also promises to enable a variety of other applications in high energy density (HED) and inertial confinement fusion (ICF) research.

    In a recently published Physics of Plasmas paper, an international team of researchers reported that the maximum proton energies created in the February 2018 experiments — from 14 to 18 MeV (million electron volts) — are “indicative of (an)…electron acceleration mechanism that sustains acceleration over long (multi-picosecond) time-scales and allows for proton energies to be achieved far beyond what the well-established scalings of proton acceleration (at ARC-level intensities) would predict.

    “Coupled with the NIF,” the researchers said, “developing ARC laser-driven ion acceleration capabilities will enable multiple exciting applications. For example, the NIF can deliver 1.8 MJ (million joules) of laser light to drive an experiment and with an energetic proton beam, we could begin to diagnose electromagnetic fields in these experiments by using proton radiography.”

    LLNL engineering physicist Derek Mariscal, lead author of the paper, said the surprise results at ARC’s quasi-relativistic, or “modest” laser intensities — about a quintillion (1018) watts per square centimeter — “forced us to try to understand the source of these particles, and we ultimately found that a different mechanism for accelerating particles to MeV electrons was necessary to explain the results.

    “While we haven’t completely explained this mechanism,” he said, “we’ve been able to start discounting mechanisms that have been identified in previous short-pulse work to start honing in on how we could get such unexpected electron and subsequent proton energies.

    “These results are really encouraging not only for ARC-driven proton beams,” he added, “but for particle acceleration in what’s referred to as the quasi-relativistic laser regime.”

    ARC is a petawatt (quadrillion watt)-class short-pulse laser created by splitting two of NIF’s 192 long-pulse beams into four rectangular beamlets. Using a 2018 Nobel Prize-winning process called chirped-pulse amplification, the beamlets are stretched in time to reduce their peak intensity, then amplified at intensities below the optics damage threshold in the laser amplifiers and finally compressed to picosecond (trillionth of a second) pulse lengths and highest peak power in large compressor vessels, as shown in this video.

    In the experiments, which are supported by LLNL’s Laboratory Directed Research and Development (LDRD) and NIF’s Discovery Science programs, two ARC shots were fired onto 1.5×1.5-millimeter-square, 33-micron-thick titanium foils. About 2.6 kilojoules of energy were delivered in a 9.6-picosecond pulse and 1.1 kJ were fired in a 1.6-ps pulse. A Target Normal Sheath Acceleration (TNSA) field, first observed on LLNL’s Nova petawatt laser two decades ago, accelerated high-energy protons and ions from the contamination layer of proton-rich hydrocarbons and water coating the target’s surface.

    3
    Illustration of the titanium target foil, ARC beamlet pointing, and images of the proton-acceleration data captured by radiochromic film stacks placed at the front of the primary diagnostics, the NIF Electron Positron Proton Spectrometer (NEPPS) magnetic spectrometers.

    “We plan to take this platform in several directions,” Mariscal said. “One of the most obvious directions is for probing electromagnetic field structures generated during experiments driven by the NIF long-pulse beams, which has been a standard use for these proton beams since their discovery here at LLNL around 20 years ago on the Nova petawatt laser.

    “In addition to using proton beams as a diagnostic tool,” he said, “we plan to continue to use these beams to create high-energy-density conditions. Since we’re able to generate around 50 joules of proton beam energy, if we can deposit it over a 10-picosecond timescale we can generate plasmas at near solid density with temperatures over 100 eV, which is a truly exotic state of matter known as hot dense matter.”

    he researchers also are exploring new target designs that could enhance ARC’s laser intensity to achieve even higher proton energy, enabling probes of ICF experiments. And by varying the length of ARC pulses, they hope to create shaped short pulses using ARC laser beams.

    “Pulse shaping with nanosecond pulses allows for driving precision shocks in materials for studying material equations of state, but we plan to use this idea at the sub-picosecond level to manipulate particle acceleration physics,” Mariscal said. “We’ve tried this scheme on the OMEGA EP laser at the University of Rochester’s Laboratory for Laser Energetics and saw greatly enhanced laser coupling to high-energy particles over single short pulses.”
    Two-proton-beam experiments

    Additional NIF shots will use a 10-picosecond ARC beam to drive a beam of protons intended to rapidly heat a solid sample to more than 50 eV. Concurrently, a higher-intensity one-picosecond ARC beam will be used to generate a second proton beam that will probe the electromagnetic field structures of the heating experiment. “That will ultimately help us to understand how particles are being accelerated to MeV energies with a 10-picosecond pulse,” Mariscal said.

    Mariscal credited the “fantastic” suite of diagnostics at the ARC diagnostics table and modeling support from the NIF ARC laser team with enabling the researchers to learn “some very interesting fundamental short-pulse-driven particle acceleration physics in this new regime provided by ARC.

    “We’re given a new level of confidence in our interpretations due to the high-quality characterization of delivered ARC laser pulses,” he said. “This allows our physics team to accurately model the laser conditions of the experiment and maximize our understanding from the limited overall number of ARC laser experiments.”

    Joining Mariscal on the paper were LLNL colleagues Tammy Ma, Scott Wilks, Andreas Kemp, G. Jackson Williams, Pierre Michel, Hui Chen, Prav Patel, Bruce Remington, Mark Bowers, Lawrence Pelz, Mark Hermann, Warren Hsing, David Martinez, Ron Sigurdsson, Matt Prantil, Alan Conder, Janice Lawson, Matt Hamamoto, Pascal Di Nicola, Clay Widmayer, Doug Homoelle, Roger Lowe-Webb, Sandrine Herriot, Wade Williams, David Alessi, Dan Kalantar, Rich Zacharias, Constantin Haefner, Nathaniel Thompson, Thomas Zobrist, Dawn Lord, Nicholas Hash, Arthur Pak, Nuno Lemos and Max Tabak, along with collaborators from the University of California at San Diego, General Atomics, the University of Oxford and the Central Laser Facility at the STFC Rutherford Appleton Laboratory in the UK, the Institute of Laser Engineering at Osaka University in Japan and Los Alamos National Laboratory.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    LLNL Campus

    Operated by Lawrence Livermore National Security, LLC, for the Department of Energy’s National Nuclear Security Administration
    Lawrence Livermore National Laboratory (LLNL) is an American federal research facility in Livermore, California, United States, founded by the University of California, Berkeley in 1952. A Federally Funded Research and Development Center (FFRDC), it is primarily funded by the U.S. Department of Energy (DOE) and managed and operated by Lawrence Livermore National Security, LLC (LLNS), a partnership of the University of California, Bechtel, BWX Technologies, AECOM, and Battelle Memorial Institute in affiliation with the Texas A&M University System. In 2012, the laboratory had the synthetic chemical element livermorium named after it.
    LLNL is self-described as “a premier research and development institution for science and technology applied to national security.” Its principal responsibility is ensuring the safety, security and reliability of the nation’s nuclear weapons through the application of advanced science, engineering and technology. The Laboratory also applies its special expertise and multidisciplinary capabilities to preventing the proliferation and use of weapons of mass destruction, bolstering homeland security and solving other nationally important problems, including energy and environmental security, basic science and economic competitiveness.

    The Laboratory is located on a one-square-mile (2.6 km2) site at the eastern edge of Livermore. It also operates a 7,000 acres (28 km2) remote experimental test site, called Site 300, situated about 15 miles (24 km) southeast of the main lab site. LLNL has an annual budget of about $1.5 billion and a staff of roughly 5,800 employees.

    LLNL was established in 1952 as the University of California Radiation Laboratory at Livermore, an offshoot of the existing UC Radiation Laboratory at Berkeley. It was intended to spur innovation and provide competition to the nuclear weapon design laboratory at Los Alamos in New Mexico, home of the Manhattan Project that developed the first atomic weapons. Edward Teller and Ernest Lawrence,[2] director of the Radiation Laboratory at Berkeley, are regarded as the co-founders of the Livermore facility.

    The new laboratory was sited at a former naval air station of World War II. It was already home to several UC Radiation Laboratory projects that were too large for its location in the Berkeley Hills above the UC campus, including one of the first experiments in the magnetic approach to confined thermonuclear reactions (i.e. fusion). About half an hour southeast of Berkeley, the Livermore site provided much greater security for classified projects than an urban university campus.

    Lawrence tapped 32-year-old Herbert York, a former graduate student of his, to run Livermore. Under York, the Lab had four main programs: Project Sherwood (the magnetic-fusion program), Project Whitney (the weapons-design program), diagnostic weapon experiments (both for the Los Alamos and Livermore laboratories), and a basic physics program. York and the new lab embraced the Lawrence “big science” approach, tackling challenging projects with physicists, chemists, engineers, and computational scientists working together in multidisciplinary teams. Lawrence died in August 1958 and shortly after, the university’s board of regents named both laboratories for him, as the Lawrence Radiation Laboratory.

    Historically, the Berkeley and Livermore laboratories have had very close relationships on research projects, business operations, and staff. The Livermore Lab was established initially as a branch of the Berkeley laboratory. The Livermore lab was not officially severed administratively from the Berkeley lab until 1971. To this day, in official planning documents and records, Lawrence Berkeley National Laboratory is designated as Site 100, Lawrence Livermore National Lab as Site 200, and LLNL’s remote test location as Site 300.[3]

    The laboratory was renamed Lawrence Livermore Laboratory (LLL) in 1971. On October 1, 2007 LLNS assumed management of LLNL from the University of California, which had exclusively managed and operated the Laboratory since its inception 55 years before. The laboratory was honored in 2012 by having the synthetic chemical element livermorium named after it. The LLNS takeover of the laboratory has been controversial. In May 2013, an Alameda County jury awarded over $2.7 million to five former laboratory employees who were among 430 employees LLNS laid off during 2008.[4] The jury found that LLNS breached a contractual obligation to terminate the employees only for “reasonable cause.”[5] The five plaintiffs also have pending age discrimination claims against LLNS, which will be heard by a different jury in a separate trial.[6] There are 125 co-plaintiffs awaiting trial on similar claims against LLNS.[7] The May 2008 layoff was the first layoff at the laboratory in nearly 40 years.[6]

    On March 14, 2011, the City of Livermore officially expanded the city’s boundaries to annex LLNL and move it within the city limits. The unanimous vote by the Livermore city council expanded Livermore’s southeastern boundaries to cover 15 land parcels covering 1,057 acres (4.28 km2) that comprise the LLNL site. The site was formerly an unincorporated area of Alameda County. The LLNL campus continues to be owned by the federal government.

    LLNL/NIF


    DOE Seal
    NNSA

     
  • richardmitnick 11:05 am on May 16, 2019 Permalink | Reply
    Tags: Laser Technology, , Phonon lasers, , The optical tweezer   

    From The Conversation: “Laser of sound promises to measure extremely tiny phenomena” 

    Conversation
    From The Conversation

    May 16, 2019
    Mishkat Bhattacharya
    Associate Professor of Physics and Astronomy, Rochester Institute of Technology

    Nick Vamivakas
    Associate Professor of Quantum Optics & Quantum Physics, University of Rochester

    1
    The crests (bright) and troughs (dark) of waves spread out after they were produced. The picture applies to both light and sound waves. Titima Ongkantong

    Most people are familiar with optical lasers through their experience with laser pointers. But what about a laser made from sound waves?

    What makes optical laser light different from a light bulb or the sun is that all the light waves emerging from it are moving in the same direction and are pretty much in perfect step with each other. This is why the beam coming out of the laser pointer does not spread out in all directions.

    In contrast, rays from the sun and light from a light bulb go in every direction. This is a good thing because otherwise it would be difficult to illuminate a room; or worse still, the Earth might not receive any sunlight. But keeping the light waves in step – physicists call it coherence – is what makes a laser special. Sound is also made of waves.

    Recently there has been considerable scientific interest in creating phonon lasers in which the oscillations of light waves are replaced by the vibrations of a tiny solid particle. By generating sound waves that are perfectly synchronized, we figured out how to make a phonon laser – or a “laser for sound.”

    In work we recently published in the journal Nature Photonics, we have constructed our phonon laser using the oscillations of a particle – about a hundred nanometers in diameter – levitated using an optical tweezer.

    2
    A red laser beam from a high-power lab laser. Doug McLean/Shutterstock.com

    Waves in sync

    An optical tweezer is simply a laser beam which goes through a lens and traps a nanoparticle in midair, like the tractor beam in “Star Wars.” The nanoparticle does not stay still. It swings back and forth like a pendulum, along the direction of the trapping beam.

    Since the nanoparticle is not clamped to a mechanical support or tethered to a substrate, it is very well isolated from its surrounding environment. This enables physicists like us to use it for sensing weak electric, magnetic and gravitational forces whose effects would be otherwise obscured.

    To improve the sensing capability, we slow or “cool” the nanoparticle motion. This is done by measuring the position of the particle as it changes with time. We then feed that information back into a computer that controls the power in the trapping beam. Varying the trapping power allows us to constrain the particle so that it slows down. This setup has been used by several groups around the world in applications that have nothing to do with sound lasers. We then took a crucial step that makes our device unique and is essential for building a phonon laser.

    This involved modulating the trapping beam to make the nanoparticle oscillate faster, yielding laser-like behavior: The mechanical vibrations of the nanoparticle produced synchronized sound waves, or a phonon laser.

    The phonon laser is a series of synchronized sound waves. A detector can monitor the phonon laser and identify changes in the pattern of these sound waves that reveal the presence of a gravitational or magnetic force.

    It might appear that the particle becomes less sensitive because it is oscillating faster, but the effect of having all the oscillations in sync actually overcomes that effect and makes it a more sensitive instrument.

    3
    An artist’s depiction of optical tweezers (pink) holding the nanoparticle in midair, while allowing it to move back and forth and create sound waves. A. Nick Vamivakas and Michael Osadciw, University of Rochester illustration, CC BY-SA

    Possible applications

    It is clear that optical lasers are very useful. They carry information over optical fiber cables, read bar codes in supermarkets and run the atomic clocks which are essential for GPS.

    We originally developed the phonon laser as a tool for detecting weak electric, magnetic and gravitational fields, which affect the sound waves in a way we can detect. But we hope that others will find new uses for this technology in communication and sensing, such as the mass of very small molecules.

    On the fundamental side, our work leverages current interest in testing quantum physics theories about the behavior of collections of billion atoms – roughly the number contained in our nanoparticle. Lasers are also the starting point for creating exotic quantum states like the famous Schrodinger cat state, which allows an object to be in two places at the same time. Of course the most exciting uses of the optical tweezer phonon laser may well be ones we cannot currently foresee.

    See the full article here .

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

    Please help promote STEM in your local schools.

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    The Conversation launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 10:45 am on May 14, 2019 Permalink | Reply
    Tags: , “Tractor beam”, “What I want to do is understand these complex biological processes using the laws and tools of physics.”, , For Lee these multidisciplinary projects reflect the essence of his chosen calling: biophysics., Laser Technology, Lee is also able to generate ultra-high resolution images of neuron development for research aimed at finding improved treatments for degenerative diseases., Lee is principal investigator on a $1.5 million Department of Energy project—with his Rutgers team (Shishir Chundawat; Eric Lam; and Laura Fabris), Lee says “I became determined to understand biological processes through the simple universal and beautiful principles of physics.”, Lee’s device allows him to examine live plant cells in “unprecedented molecular detail” for a project that could help break new ground in the development of biofuels., , Rutgers physicist Sang-Hyuk Lee, , The development of optical tweezers goes back decades., The instrument uses a focused laser beam to trap hold and move microscopic objects that previously had been too tiny to touch.   

    From Rutgers University: “Once a Dream of Science Fiction, a Laser Tweezer Helps a Rutgers Biophysicist Boldly Go Where Molecules Move” 

    Rutgers smaller
    Our Great Seal.

    From Rutgers University

    THIS POST IS DEDICATED TO L.Z. OF RUTGERS UNIVERSITY PHYSICS AND H.P.

    5.14.19
    John Chadwick

    Sang-Hyuk Lee integrates two Nobel Prize-winning innovations.

    1
    Sang-Hyuk Lee

    “An old dream of science fiction,” the Nobel Prize Committee said in its praise of the invention.

    Like the “tractor beam” of vintage Star Trek episodes others observed.

    The futuristic device they’re talking about is optical tweezers.

    Invented by Arthur Ashkin, one of three pioneers in laser physics to win the 2018 Nobel Prize in Physics, the instrument uses a focused laser beam to trap, hold, and move microscopic objects that previously had been too tiny to touch.

    2
    Sang-Hyuk Lee with Nobel Prize winning device, “tractor beam”

    The revolutionary tool is essential to the work of a Rutgers professor who recently brought the technology to the university. Sang-Hyuk Lee, of the Department of Physics and Astronomy, School of Arts and Sciences, has also added advanced microscopy techniques to make the device capable of examining and visualizing molecules at the tiniest level.

    He is using the innovative instrument for several federally-funded research projects that combine elements of physics and biology.

    Lee’s device allows him to examine live plant cells in “unprecedented molecular detail” for a project that could help break new ground in the development of biofuels. He is also able to generate ultra-high resolution images of neuron development for research aimed at finding improved treatments for degenerative diseases.

    For Lee, these multidisciplinary projects reflect the essence of his chosen calling: biophysics.

    “A biophysicist is bridging the gap between two worlds,” he says. “What I want to do is understand these complex biological processes using the laws and tools of physics.”

    The optical tweezers provide him with the perfect tool for that mission.

    The development of optical tweezers goes back decades. Ashkin, who was the head of laser science at Bell Labs in Holmdel, N.J., from 1963 to 1987, set out to build an instrument capable of grabbing particles, atoms, molecules, and living cells with “laser beam fingers,” according to NobelPrize.org. A major breakthrough came in 1987, when Ashkin succeeded in capturing living bacteria without harming them.

    Optical tweezers can move and manipulate particles smaller than a micron. A single strand of human hair is about 75 microns in width.

    Lee became intrigued by the technology while working on his doctorate at New York University under David Grier, a physicist who created more complex versions of optical tweezers by adding digital holography. Lee was also influenced by, and later worked as a post-doc for Carlos Bustamante, a biophysicist at the University of California, Berkeley, who used optical tweezers to stretch a single DNA molecule to measure the force holding it together.

    “His work completely changed my views of biology,” Lee says. “I became determined to understand biological processes through the simple, universal, and beautiful principles of physics.”

    After arriving at Rutgers in 2015, Lee designed and built the mammoth instrument that’s now housed within a glass enclosure in a laboratory at the Institute for Quantitative Biomedicine on Busch Campus. The device is far more versatile than commercially available models because Lee integrated a number of advanced optics techniques, including use of multiple lasers, and a technology known as super resolution fluorescence microscopy, which won the 2014 Nobel in Chemistry for producing higher resolution image than what conventional light microscopes could achieve.

    “So, we can get super-resolution image of intra-cellular structures while we exert measure force on individual molecules,” he says. “Our instrument is a one-of-a-kind, home-built microscope.”

    Physics Chair Robert Bartynski agrees. And he said the application of laser physics to contemporary problems in biology is opening an exciting new chapter in interdisciplinary science.

    4
    Nobel Prize winning device, “Tractor Beam”

    “The optical tweezers technology that Sang-Hyuk has developed at Rutgers give us a singular capability that expands our understanding of how biomolecules move in and around cells to carry out critical tasks,” Bartynski said. “The ability to manipulate and visualize individual molecules with these advanced optical techniques, will give unprecedented insights into the physics behind key biological processes

    Lee is principal investigator on a $1.5 million Department of Energy project—with his Rutgers team (Shishir Chundawat, Eric Lam and Laura Fabris), along with collaborators at Vanderbilt University and Oak Ridge National Laboratory—that seeks to understand how cell walls in plants are formed—knowledge that may accelerate the development of genetically engineered crops for use as renewable fuels and have broad impact on molecular and cellular biology fields in general.

    He is also involved in a National Science Foundation-funded project—with Nada N. Boustany, a Rutgers professor of biomedical engineering serving as principal investigator—that could help improve treatments for degenerative neural diseases or nerve injury due to trauma.

    Lee describes his research focus as “single-molecule biophysics,” the study of individual biomolecules to understand how they carry out their functions in living cells.

    “The application to important biology problems is still in its infancy,” he says. “This emerging field has tremendous potential.

    See the full article here .


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    Please help promote STEM in your local schools.

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    rutgers-campus

    Rutgers, The State University of New Jersey, is a leading national research university and the state’s preeminent, comprehensive public institution of higher education. Rutgers is dedicated to teaching that meets the highest standards of excellence; to conducting research that breaks new ground; and to providing services, solutions, and clinical care that help individuals and the local, national, and global communities where they live.

    Founded in 1766, Rutgers teaches across the full educational spectrum: preschool to precollege; undergraduate to graduate; postdoctoral fellowships to residencies; and continuing education for professional and personal advancement.

    As a ’67 graduate of University college, second in my class, I am proud to be a member of

    Alpha Sigma Lamda, National Honor Society of non-tradional students.

     
  • richardmitnick 8:01 am on May 10, 2019 Permalink | Reply
    Tags: "Q&A: SLAC/Stanford researchers prepare for a new quantum revolution", , , , , Laser Technology, , , , , Quantum squeezing, , The most exciting opportunities in quantum control make use of a phenomenon known as entanglement   

    From SLAC National Accelerator Lab- “Q&A: SLAC/Stanford researchers prepare for a new quantum revolution” 

    From SLAC National Accelerator Lab

    May 9, 2019
    Manuel Gnida

    Monika Schleier-Smith and Kent Irwin explain how their projects in quantum information science could help us better understand black holes and dark matter.

    The tech world is abuzz about quantum information science (QIS). This emerging technology explores bizarre quantum effects that occur on the smallest scales of matter and could potentially revolutionize the way we live.

    Quantum computers would outperform today’s most powerful supercomputers; data transfer technology based on quantum encryption would be more secure; exquisitely sensitive detectors could pick up fainter-than-ever signals from all corners of the universe; and new quantum materials could enable superconductors that transport electricity without loss.

    In December 2018, President Trump signed the National Quantum Initiative Act into law, which will mobilize $1.2 billion over the next five years to accelerate the development of quantum technology and its applications. Three months earlier, the Department of Energy had already announced $218 million in funding for 85 QIS research awards.

    The Fundamental Physics and Technology Innovation directorates of DOE’s SLAC National Accelerator Laboratory recently joined forces with Stanford University on a new initiative called Q-FARM to make progress in the field. In this Q&A, two Q-FARM scientists explain how they will explore the quantum world through projects funded by DOE QIS awards in high-energy physics.

    Monika Schleier-Smith, assistant professor of physics at Stanford, wants to build a quantum simulator made of atoms to test how quantum information spreads. The research, she said, could even lead to a better understanding of black holes.

    Kent Irwin, professor of physics at Stanford and professor of photon science and of particle physics and astrophysics at SLAC, works on quantum sensors that would open new avenues to search for the identity of the mysterious dark matter that makes up most of the universe.

    1
    Monika Schleier-Smith and Kent Irwin are the principal investigators of three quantum information science projects in high-energy physics at SLAC. (Farrin Abbott/Dawn Harmer/SLAC National Accelerator Laboratory)

    What exactly is quantum information science?

    Irwin: If we look at the world on the smallest scales, everything we know is already “quantum.” On this scale, the properties of atoms, molecules and materials follow the rules of quantum mechanics. QIS strives to make significant advances in controlling those quantum effects that don’t exist on larger scales.

    Schleier-Smith: We’re truly witnessing a revolution in the field in the sense that we’re getting better and better at engineering systems with carefully designed quantum properties, which could pave the way for a broad range of future applications.

    What does quantum control mean in practice?

    Schleier-Smith: The most exciting opportunities in quantum control make use of a phenomenon known as entanglement – a type of correlation that doesn’t exist in the “classical,” non-quantum world. Let me give you a simple analogy: Imagine that we flip two coins. Classically, whether one coin shows heads or tails is independent of what the other coin shows. But if the two coins are instead in an entangled quantum state, looking at the result for one “coin” automatically determines the result for the other one, even though the coin toss still looks random for either coin in isolation.

    Entanglement thus provides a fundamentally new way of encoding information – not in the states of individual “coins” or bits but in correlations between the states of different qubits. This capability could potentially enable transformative new ways of computing, where problems that are intrinsically difficult to solve on classical computers might be more efficiently solved on quantum ones. A challenge, however, is that entangled states are exceedingly fragile: any measurement of the system – even unintentional – necessarily changes the quantum state. So a major area of quantum control is to understand how to generate and preserve this fragile resource.

    At the same time, certain quantum technologies can also take advantage of the extreme sensitivity of quantum states to perturbations. One application is in secure telecommunications: If a sender and receiver share information in the form of quantum bits, an eavesdropper cannot go undetected, because her measurement necessarily changes the quantum state.

    Another very promising application is quantum sensing, where the idea is to reduce noise and enhance sensitivity by controlling quantum correlations, for instance, through quantum squeezing.

    What is quantum squeezing?

    Irwin: Quantum mechanics sets limits on how we can measure certain things in nature. For instance, we can’t perfectly measure both the position and momentum of a particle. The very act of measuring one changes the other. This is called the Heisenberg uncertainty principle. When we search for dark matter, we need to measure an electromagnetic signal extremely well, but Heisenberg tells us that we can’t measure the strength and timing of this signal without introducing uncertainty.

    Quantum squeezing allows us to evade limits on measurement set by Heisenberg by putting all the uncertainty into one thing (which we don’t care about), and then measuring the other with much greater precision. So, for instance, if we squeeze all of the quantum uncertainty in an electromagnetic signal into its timing, we can measure its strength much better than quantum mechanics would ordinarily allow. This lets us search for an electromagnetic signal from dark matter much more quickly and sensitively than is otherwise possible.

    2
    Kent Irwin (at left with Dale Li) leads efforts at SLAC and Stanford to build quantum sensors for exquisitely sensitive detectors. (Andy Freeberg/SLAC National Accelerator Laboratory)

    What types of sensors are you working on?

    Irwin: My team is exploring quantum techniques to develop sensors that could break new ground in the search for dark matter.

    We’ve known since the 1930s that the universe contains much more matter than the ordinary type that we can see with our eyes and telescopes – the matter made up of atoms. Whatever dark matter is, it’s a new type of particle that we don’t understand yet. Most of today’s dark matter detectors search for relatively heavy particles, called weakly interacting massive particles, or WIMPs.

    PandaX II Dark Matter experiment at Jin-ping Underground Laboratory (CJPL) in Sichuan, China

    DEAP Dark Matter detector, The DEAP-3600, suspended in the SNOLAB deep in Sudbury’s Creighton Mine

    LBNL LZ project at SURF, Lead, SD, USA

    But what if dark matter particles were so light that they wouldn’t leave a trace in those detectors? We want to develop sensors that would be able to “see” much lighter dark matter particles.

    There would be so many of these very light dark matter particles that they would behave much more like waves than individual particles. So instead of looking for collisions of individual dark matter particles within a detector, which is how WIMP detectors work, we want to look for dark matter waves, which would be detected like a very weak AM radio signal.

    In fact, we even call one of our projects “Dark Matter Radio.” It works like the world’s most sensitive AM radio. But it’s also placed in the world’s most perfect radio shield, made up of a material called a superconductor, which keeps all normal radio waves out. However, unlike real AM radio signals, dark matter waves would be able to go right through the shield and produce a signal. So we are looking for a very weak AM radio station made by dark matter at an unknown frequency.

    Quantum sensors can make this radio much more sensitive, for instance by using quantum tricks such as squeezing and entanglement. So the Dark Matter Radio will not only be the world’s most sensitive AM radio; it will also be better than the Heisenberg uncertainty principle would normally allow.

    What are the challenges of QIS?

    Schleier-Smith: There is a lot we need to learn about controlling quantum correlations before we can make broad use of them in future applications. For example, the sensitivity of entangled quantum states to perturbations is great for sensor applications. However, for quantum computing it’s a major challenge because perturbations of information encoded in qubits will introduce errors, and nobody knows for sure how to correct for them.

    To make progress in that area, my team is studying a question that is very fundamental to our ability to control quantum correlations: How does information actually spread in quantum systems?

    The model system we’re using for these studies consists of atoms that are laser-cooled and optically trapped. We use light to controllably turn on interactions between the atoms, as a means of generating entanglement. By measuring the speed with which quantum information can spread in the system, we hope to understand how to design the structure of the interactions to generate entanglement most efficiently. We view the system of cold atoms as a quantum simulator that allows us to study principles that are also applicable to other physical systems.

    In this area of quantum simulation, one major thrust has been to advance understanding of solid-state systems, by trapping atoms in arrays that mimic the structure of a crystalline material. In my lab, we are additionally working to extend the ideas and tools of quantum simulation in new directions. One prospect that I am particularly excited about is to use cold atoms to simulate what happens to quantum information in black holes.

    3
    Monika Schleier-Smith (at center with graduate students Emily Davis and Eric Cooper) uses laser-cooled atoms in her lab at Stanford to study the transfer of quantum information. (Dawn Harmer/SLAC National Accelerator Laboratory)

    What do cold atoms have to do with black holes?

    Schleier-Smith: The idea that there might be any connection between quantum systems we can build in the lab and black holes has its origins in a long-standing theoretical problem: When particles fall into a black hole, what happens to the information they contained? There were compelling arguments that the information should be lost, but that would contradict the laws of quantum mechanics.

    More recently, theoretical physicists – notably my Stanford colleague Patrick Hayden – found a resolution to this problem: We should think of the black hole as a highly chaotic system that “scrambles” the information as fast as physically possible. It’s almost like shredding documents, but quantum information scrambling is much richer in that the result is a highly entangled quantum state.

    Although precisely recreating such a process in the lab will be very challenging, we hope to look at one of its key features already in the near term. In order for information scrambling to happen, information needs to be transferred through space exponentially fast. This, in turn, requires quantum interactions to occur over long distances, which is quite counterintuitive because interactions in nature typically become weaker with distance. With our quantum simulator, we are able to study interactions between distant atoms by sending information back and forth with photons, particles of light.

    What do you hope will happen in QIS over the next few years?

    Irwin: We need to prove that, in real applications, quantum technology is superior to the technology that we already have. We are in the early stages of this new quantum revolution, but this is already starting to happen. The things we’re learning now will help us make a leap in developing future technology, such as universal quantum computers and next-generation sensors. The work we do on quantum sensors will enable new science, not only in dark matter research. At SLAC, I also see potential for quantum-enhanced sensors in X-ray applications, which could provide us with new tools to study advanced materials and understand how biomolecules work.

    Schleier-Smith: QIS offers plenty of room for breakthroughs. There are many open questions we still need to answer about how to engineer the properties of quantum systems in order to harness them for technology, so it’s imperative that we continue to broadly advance our understanding of complex quantum systems. Personally, I hope that we’ll be able to better connect experimental observations with the latest theoretical advances. Bringing all this knowledge together will help us build the technologies of the future.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

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    SLAC/LCLS


    SLAC/LCLS II projected view


    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.

     
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