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  • richardmitnick 2:23 pm on March 27, 2015 Permalink | Reply
    Tags: China Academy of Engineering and Physics, European XFEL, X-ray Technology   

    From XFEL: “Major Chinese research centre signs collaboration agreement” 

    XFEL bloc

    European XFEL

    Officials at the signing ceremony at the Consulate of the People’s Republic of China in Hamburg. Front row, from left: European XFEL Administrative Director Claudia Burger, CAEP Vice Director Liu Cangli, European XFEL Managing Director Massimo Altarelli. Back row, from left: Consul-General of the People’s Republic of China Yang Huiqun, Counsellor Zhao Qinhua from the Embassy of the People’s Republic of China in Germany. European XFEL

    On 26 March, representatives of the China Academy of Engineering Physics (CAEP) signed a framework collaboration agreement with European XFEL at the Consulate of the People’s Republic of China in Hamburg.

    The agreement formalizes CAEP’s future involvement in the X-ray free-electron laser facility and is intended to provide the basis for future exchange of staff and students and the development of instrumentation for European XFEL. CAEP is a major research centre that operates 12 research institutes and 15 national laboratories across China. In many scientific institutes across China, there is a rising interest in doing research with X-ray free-electron lasers, and CAEP looks to spearhead Chinese involvement with these facilities.

    “As time goes by, I hope we will be able to estimate material properties with ever decreasing uncertainties. One of the significant issues here might be the poor understanding of the phenomena at meso-scale”, says CAEP Vice Director Liu Cangli. “We see a powerful XFEL, such as this one under construction in Hamburg, as being the most important tool in terms of taking on this very challenging task.”

    European XFEL Managing Director Massimo Altarelli says: “We are very happy about the involvement of the CAEP, and we greatly appreciate their interest in the European XFEL. Their expertise across many areas of physics and engineering will be of considerable value to the research at this facility.”

    See the full article here.

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    XFEL Campus

    The Hamburg area will soon boast a research facility of superlatives: The European XFEL will generate ultrashort X-ray flashes—27 000 times per second and with a brilliance that is a billion times higher than that of the best conventional X-ray radiation sources.

    The outstanding characteristics of the facility are unique worldwide. Starting in 2017, it will open up completely new research opportunities for scientists and industrial users.

  • richardmitnick 12:03 pm on March 24, 2015 Permalink | Reply
    Tags: , , Warm Dense Matter, X-ray Technology   

    From SLAC: “Experiment Provides the Best Look Yet at ‘Warm Dense Matter’ at Cores of Giant Planets” 

    SLAC Lab

    March 23, 2015

    Shock Wave Experiment at SLAC’s X-ray Laser Tracks Formation of a Mysterious Type of Matter

    In an experiment at the Department of Energy’s SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as it transitions into a superhot, highly compressed concoction known as “warm dense matter.”

    This illustration shows a cutaway view of Jupiter, which is believed to contain “warm dense matter” at its core. A study at SLAC’s Linac Coherent Light Source X-ray laser has provided the most detailed measurements yet of a material’s temperature and compression as it transitions into this exotic state of matter. (SLAC National Accelerator Laboratory)

    Warm dense matter is the stuff believed to be at the cores of giant gas planets in our solar system and some of the newly observed “exoplanets” that orbit distant suns, which can be many times more massive than Jupiter. Their otherworldly properties, which stretch our understanding of planetary formation, have excited new interest in studies of this exotic state of matter.

    The results of the SLAC study, published March 23 in Nature Photonics, could also lead to a greater understanding of how to produce and control nuclear fusion, which scientists hope to harness as a new source of energy.

    “The heating and compression of warm dense matter has never been measured before in a laboratory with such precise timing,” says Siegfried Glenzer, a distinguished staff scientist who is part of the Stanford Institute for Materials and Energy Sciences (SIMES) at SLAC. “We have shown the detailed steps of how a solid hit by powerful lasers becomes a compressed solid and a dense plasma at the same time. This is a step on the path toward creating fusion in the lab.”

    This video describes how scientists at SLAC created and precisely measured the temperature and compression in “warm dense matter,” an exotic state that is believed to exist at the core of giant planets like Jupiter. (SLAC National Accelerator Laboratory)

    A team led by Glenzer used laser light to compress ultrathin aluminum foil samples to a pressure more than 4,500 times higher than the deepest ocean depths and superheat it to 20,000 kelvins – about four times hotter than the surface of the sun. SLAC’s Linac Coherent Light Source X-ray laser, a DOE Office of Science User Facility, then precisely measured the foil’s properties as it transformed into warm dense matter and then into a plasma – a very hot gas of electrons and supercharged atoms.

    SLAC LCLS Inside

    Warm dense matter remains largely mysterious because it is difficult to create and study in a laboratory, can exhibit properties of several types of matter and occupies a middle ground between solid and plasma. Our own sun is an example of a self-sustaining plasma, and plasmas have also been harnessed in some TV displays.

    While warm dense matter is believed to exist in a stable state at the heart of giant planets, in a laboratory it lasts just billionths of a second. Scientists have relied largely on computer simulations, driven by scientific theories, to help explain how a solid, when shocked with powerful lasers, transforms into a plasma.

    LCLS, with its complement of high-power lasers, is uniquely suited to creating and studying matter at the extremes. Its ultrabright X-ray pulses are measured in femtoseconds, or quadrillionths of a second, so it works like an ultra-high-speed X-ray camera to illuminate and record the properties of the most fleeting phenomena in atomic-scale detail.

    In this experiment, researchers used a high-power optical laser at LCLS’s Matter in Extreme Conditions experimental station to fire separate beams of green laser light simultaneously at both sides of coated, ultrathin aluminum foil samples, each just half the width of an average human hair. The lasers produced shock waves in the material that converged to create extreme temperatures and pressures.

    Scientists prepare for an experiment at SLAC’s Matter in Extreme Conditions (MEC) station, part of the Linac Coherent Light Source X-ray laser. They used this MEC station to create and measure the properties of ultrathin sheets of superheated aluminum as it transitioned into warm dense matter, an exotic state of matter.(SLAC National Accelerator Laboratory)

    Researchers struck the samples with X-rays just nanoseconds later, and varied the arrival time of the X-rays to essentially make a series of snapshots of warm dense matter formation. The team used a technique known as small angle X-ray scattering to measure the internal structure of the material, capturing its brief transition into the warm dense state.

    “This early work with aluminum is a first stepping stone toward other problems we really need to solve,” Glenzer said, such as how hydrogen behaves under similar conditions. Hydrogen, which makes up about 75 percent of the visible mass of the universe, plays a central role in fusion, the process that powers stars. A better understanding of how hydrogen transitions into warm dense matter could help settle debates over conflicting theories on this transition and help unlock the secrets of fusion energy.

    “I think LCLS can help to resolve the hydrogen ‘controversy,’ in upcoming experiments,” Glenzer said.

    Participants in the research included scientists at SLAC, University of California Berkeley, Lawrence Livermore National Laboratory and General Atomics; QuantumWise A/S in Denmark; AWE plc, University of Warwick and University of Oxford in the U.K.; and the Max Planck Institute for the Physics of Complex Systems, Institute for Optics and Quantum Electronics, Friedrich-Schiller-University and GSI Helmholtz Center for Heavy Ion Research in Germany.

    The work was supported by the DOE Office of Science, Fusion Energy Science; the DOE Office of Basic Energy Sciences, Materials Sciences and Engineering Division; Lawrence Livermore National Laboratory; a Laboratory Directed Research and Development grant; and the Peter-Paul-Ewald Fellowship of the VolkswagenStiftung.

    See the full article here.

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

  • richardmitnick 8:41 am on March 19, 2015 Permalink | Reply
    Tags: , , , , , X-ray Technology   

    From SLAC: “Scientists Watch Quantum Dots ‘Breathe’ in Response to Stress” 

    SLAC Lab

    March 18, 2015

    Nanocrystal Study at SLAC’s X-ray Laser Could Aid in the Design of New Materials

    In this illustration, intense X-rays produced at SLAC’s Linac Coherent Light Source strike nanocrystals of a semiconductor material. Scientists used the X-rays to study an ultrafast “breathing” response in the crystals induced quadrillionths of a second earlier by laser light. (SLAC National Accelerator Laboratory)

    Researchers at the Department of Energy’s SLAC National Accelerator Laboratory watched nanoscale semiconductor crystals expand and shrink in response to powerful pulses of laser light. This ultrafast “breathing” provides new insight about how such tiny structures change shape as they start to melt – information that can help guide researchers in tailoring their use for a range of applications.

    In the experiment using SLAC’s Linac Coherent Light Source (LCLS) X-ray laser, a DOE Office of Science User Facility, researchers first exposed the nanocrystals to a burst of laser light, followed closely by an ultrabright X-ray pulse that recorded the resulting structural changes in atomic-scale detail at the onset of melting.

    SLAC LCLS Inside

    “This is the first time we could measure the details of how these ultrasmall materials react when strained to their limits,” said Aaron Lindenberg, an assistant professor at SLAC and Stanford who led the experiment. The results were published March 12 in Nature Communications.

    Getting to Know Quantum Dots

    The crystals studied at SLAC are known as “quantum dots” because they display unique traits at the nanoscale that defy the classical physics governing their properties at larger scales. The crystals can be tuned by changing their size and shape to emit specific colors of light, for example.

    So scientists have worked to incorporate them in solar panels to make them more efficient and in computer displays to improve resolution while consuming less battery power. These materials have also been studied for potential use in batteries and fuel cells and for targeted drug delivery.

    Scientists have also discovered that these and other nanomaterials, which may contain just tens or hundreds of atoms, can be far more damage-resistant than larger bits of the same materials because they exhibit a more perfect crystal structure at the tiniest scales. This property could prove useful in battery components, for example, as smaller particles may be able to withstand more charging cycles than larger ones before degrading.

    A Surprise in the ‘Breathing’ of Tiny Spheres and Nanowires

    In the LCLS experiment, researchers studied spheres and nanowires made of cadmium sulfide and cadmium selenide that were just 3 to 5 nanometers, or billionths of a meter, across. The nanowires were up to 25 nanometers long. By comparison, amino acids – the building blocks of proteins – are about 1 nanometer in length, and individual atoms are measured in tenths of nanometers.

    By examining the nanocrystals from many different angles with X-ray pulses, researchers reconstructed how they change shape when hit with an optical laser pulse. They were surprised to see the spheres and nanowires expand in width by about 1 percent and then quickly contract within femtoseconds, or quadrillionths of a second. They also found that the nanowires don’t expand in length, and showed that the way the crystals respond to strain was coupled to how their structure melts.

    In an earlier, separate study, another team of researchers had used LCLS to explore the response of larger gold particles on longer timescales.

    “In the future, we want to extend these experiments to more complex and technologically relevant nanostructures, and also to enable X-ray exploration of nanoscale devices while they are operating,” Lindenberg said. “Knowing how materials change under strain can be used together with simulations to design new materials with novel properties.”

    Participating researchers were from SLAC, Stanford and two of their joint institutes, the Stanford Institute for Materials and Energy Sciences (SIMES) and Stanford PULSE Institute; University of California, Berkeley; University of Duisburg-Essen in Germany; and Argonne National Laboratory. The work was supported by the DOE Office of Science and the German Research Council.

    See the full article here.

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

  • richardmitnick 10:55 am on March 18, 2015 Permalink | Reply
    Tags: , , , X-ray Technology   

    From ars technica: “Shining an X-Ray torch on quantum gravity” 

    Ars Technica
    ars technica

    Mar 17, 2015
    Chris Lee

    This free electron laser could eventually provide a test of quantum gravity. BNL

    Quantum mechanics has been successful beyond the wildest dreams of its founders. The lives and times of atoms, governed by quantum mechanics, play out before us on the grand stage of space and time. And the stage is an integral part of the show, bending and warping around the actors according to the rules of general relativity. The actors—atoms and molecules—respond to this shifting stage, but they have no influence on how it warps and flows around them.

    This is puzzling to us. Why is it such a one directional thing: general relativity influences quantum mechanics, but quantum mechanics has no influence on general relativity? It’s a puzzle that is born of human expectation rather than evidence. We expect that, since quantum mechanics is punctuated by sharp jumps, somehow space and time should do the same.

    There’s also the expectation that, if space and time acted a bit more quantum-ish, then the equations of general relativity would be better behaved. In general relativity, it is possible to bend space and time infinitely sharply. This is something we simply cannot understand: what would infinitely bent space look like? To most physicists, it looks like something that cannot actually be real, indicating a problem with the theory. Might this be where the actors influence the stage?

    Quantum mechanics and relativity on the clock

    To try and catch the actors modifying the stage requires the most precise experiments ever devised. Nothing we have so far will get us close, so a new idea from a pair of German physicists is very welcome. They focus on what’s perhaps the most promising avenue for detecting quantum influences on space-time: time-dilation experiments. Modern clocks rely on the quantum nature of atoms to measure time. And the flow of time depends on relative speed and gravitational acceleration. Hence, we can test general relativity, special relativity, and quantum mechanics all in the same experiment.

    To get an idea of how this works, let’s take a look at the traditional atomic clock. In an atomic clock, we carefully prepare some atoms in a predefined superposition state: that is the atom is prepared such that it has a fifty percent chance of being in state A, and a fifty percent chance of being in state B. As time passes, the environment around the atom forces the superposition state to change. At some later point, it will have a seventy five percent chance of being in state A; even later, it will certainly be in state A. Keep on going, however, and the chance of being in state A starts to shrink, and it continues to do so until the atom is certainly in state B. Provided that the atom is undisturbed, these oscillations will continue.

    These periodic oscillations provide the perfect ticking clock. We simply define the period of an oscillation to be our base unit of time. To couple this to general relativity measurements is, in principle, rather simple. Build two clocks and place them beside each other. At a certain moment, we start counting ticks from both clocks. When one clock reaches a thousand (for instance), we compare the number of ticks from the two clocks. If we have done our job right, both clocks should have reached a thousand ticks.

    If we shoot one into space, however, and perform the same experiment, and relativity demands that the clock in orbit record more ticks than the clock on Earth. The way we record the passing of time is by a phenomena that is purely quantum in nature, while the passing of time is modified by gravity. These experiments work really well. But at present, they are not sensitive enough to detect any deviation from either quantum mechanics or general relativity.

    Going nuclear

    That’s where the new ideas come in. The researchers propose, essentially, to create something similar to an atomic clock, but instead of tracking the oscillation atomic states, they want to track nuclear states. Usually, when I discuss atoms, I ignore the nucleus entirely. Yes, it is there, but I only really care about the influence the nucleus has on the energetic states of the electrons that surround it. However, in one key way the nucleus is just like the electron cloud that surrounds it: it has its own set of energetic states. It is possible to excite nuclear states (using X-Ray radiation) and, afterwards, they will return the ground state by emitting an X-Ray.

    So let’s imagine that we have a crystal of silver sitting on the surface of the Earth. The silver atoms all experience a slightly different flow of time because the atoms at the top of the crystal are further away from the center of the Earth compared to the atoms at the bottom of the crystal.

    To kick things off, we send in a single X-Ray photon, which is absorbed by the crystal. This is where the awesomeness of quantum mechanics puts on sunglasses and starts dancing. We don’t know which silver atom absorbed the photon, so we have to consider that all of them absorbed a tiny fraction of the photon. This shared absorption now means that all of the silver atoms enter a superposition state of having absorbed and not absorbed a photon. This superposition state changes with time, just like in an atomic clock.

    In the absence of an outside environment, all the silver atoms will change in lockstep. And when the photon is re-emitted from the crystal, all the atoms will contribute to that emission. So each atom behaves as if it is emitting a partial photon. These photons add together, and a single photon flies off in the same direction as the absorbed photon had been traveling. Essentially because all the atoms are in lockstep, the charge oscillations that emit the photon add up in phase only in the direction that the absorbed photon was flying.

    Gravity, though, causes the atoms to fall out of lockstep. So when the time comes to emit, the charge oscillations are all slightly out of phase with each other. But they are not random: those at the top of the crystal are just slightly ahead of those at the bottom of the crystal. As a result, the direction for which the individual contributions add up in phase is not in the same direction as the flight path of the absorbed photon, but at a very slight angle.

    How big is this angle? That depends on the size of the crystal and how long it takes the environment to randomize the emission process. For a crystal of silver atoms that is less than 1mm thick, the angle could be as large as 100 micro-degrees, which is small but probably measurable.
    Spinning crystals

    That, however, is only the beginning of a seam of clever. If the crystal is placed on the outside of a cylinder and rotated during the experiment, then the top atoms of the crystal are moving faster than the bottom, meaning that the time-dilation experienced at the top of the crystal is greater than that at the bottom. This has exactly the same effect as placing the crystal in a gravitational field, but now the strength of that field is governed by the rate of rotation.

    In any case, by spinning a 10mm diameter cylinder very fast (70,000 revolutions per second), the angular deflection is vastly increased. For silver, for instance, it reaches 90 degrees. With such a large signal, even smaller deviations from the predictions of general relativity should be detectable in the lab. Importantly, these deviations happen on very small length scales, where we would normally start thinking about quantum effects in matter. Experiments like these may even be sensitive enough to see the influence of quantum mechanics on space and time.

    A physical implementation of this experiment will be challenging but not impossible. The biggest issue is probably the X-Ray source and doing single photon experiments in the X-Ray regime. Following that, the crystals need to be extremely pure, and something called a coherent state needs to be created within them. This is certainly not trivial. Given that it took atomic physicists a long time to achieve this for electronic transitions, I think it will take a lot more work to make it happen at X-Ray frequencies.

    On the upside free electron lasers have come a very long way, and they have much better control over beam intensities and stability. This is, hopefully, the sort of challenge that beam-line scientists live for.

    See the full article here.

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    Ars Technica was founded in 1998 when Founder & Editor-in-Chief Ken Fisher announced his plans for starting a publication devoted to technology that would cater to what he called “alpha geeks”: technologists and IT professionals. Ken’s vision was to build a publication with a simple editorial mission: be “technically savvy, up-to-date, and more fun” than what was currently popular in the space. In the ensuing years, with formidable contributions by a unique editorial staff, Ars Technica became a trusted source for technology news, tech policy analysis, breakdowns of the latest scientific advancements, gadget reviews, software, hardware, and nearly everything else found in between layers of silicon.

    Ars Technica innovates by listening to its core readership. Readers have come to demand devotedness to accuracy and integrity, flanked by a willingness to leave each day’s meaningless, click-bait fodder by the wayside. The result is something unique: the unparalleled marriage of breadth and depth in technology journalism. By 2001, Ars Technica was regularly producing news reports, op-eds, and the like, but the company stood out from the competition by regularly providing long thought-pieces and in-depth explainers.

    And thanks to its readership, Ars Technica also accomplished a number of industry leading moves. In 2001, Ars launched a digital subscription service when such things were non-existent for digital media. Ars was also the first IT publication to begin covering the resurgence of Apple, and the first to draw analytical and cultural ties between the world of high technology and gaming. Ars was also first to begin selling its long form content in digitally distributable forms, such as PDFs and eventually eBooks (again, starting in 2001).

  • richardmitnick 9:20 am on March 13, 2015 Permalink | Reply
    Tags: , , , X-ray Technology   

    From DESY: “Molecules perform endless cartwheels” 


    No Writer Credit

    An near-infrared laser (red) makes the originally disordered molecules perform synchronized cartwheels so that all the molecules at a particular position along the beam are oriented in the same direction. Picture: Jens S. Kienitz/CFEL, DESY and CUI

    Scientists in Hamburg have resorted to a physical trick to persuade entire groups of molecules to perform synchronized cartwheels, virtually endlessly. This technique opens up new opportunities for imaging molecules and their chemical dynamics. Prof. Jochen Küpper and his team at the Center for Free-Electron Laser Science (CFEL) are presenting their findings in the journal Physical Review Letters.

    The FLASH experimental hall with beamlines which guide the laser-like light of the free-electron laser FLASH to the experimental stations. (Source: DESY)

    Intense flashes of x-rays emitted by so-called free electron lasers offer detailed insights into the world of molecules. Researchers use them, for example, to explore the atomic structure of biomolecules and to better understand their function, or they try to film dynamic processes taking place in the nanocosm – such as the excitation cycle in photosynthesis. Until now, however, such molecules have generally had to be available in a crystalline form for such examinations to be carried out, because the individual molecules alone do not produce a strong enough signal. In a crystal, the molecules are arranged in regular patterns so that the signals from each add up, allowing an analysis on an atomic level.

    “Crystals represent a very special state, however – often imposed and unnatural”, explains Sebastian Trippel, the first author of the paper. Scientists would therefore often prefer to examine free molecules directly. But how can such free molecules be moved, in a controlled fashion, into the x-ray beam of a free electron laser? Scientists have been experimenting with different methods of guiding the molecules, using electromagnetic fields and laser light, and aligning them in a particular direction at the same time.

    They have already succeeded in strongly orienting entire ensembles of molecules in the same direction for such examinations, “however when you do this, the molecular ballet is influenced by an electromagnetic field, which can in turn have an unwanted effect on the measurements,” explains Jochen Küpper, a scientist at DESY, who is also a member of the Hamburger Center for Ultrafast Imaging (CUI) and a professor at the University of Hamburg. The molecular tamers working with Küpper have now found a way of preserving the alignment of molecular ensembles even after the laser field has been switched off.

    For their test, the researchers used carbonyl sulfide (OCS) as a simple model system. The three atoms that make up this molecule (carbon, oxygen and sulfur) lie in a straight line, and this simple structure makes it particularly suitable for demonstrating the method. The scientists released high-pressure carbonyl sulfide molecules into a vacuum chamber through a fine nozzle, as a result of which the gas expanded and thereby cooled down rapidly. They then used a so-called deflector, a kind of prism for molecules, to fish out those molecules that were in the lowest-energy state.

    A tailored pulse of infrared laser light mixed this state with the first excited quantum state. As a result, the molecules started to perform, synchronously, a so-called inversion, whereby the individual molecules fell in step with each other, so that the sulphur atom (S) of the molecules all simultaneously pointed up or down. This inversion continued undiminished even after the molecules had passed the infrared laser and were moving through space without being affected by an alternating electromagnetic field. “In a sense, the laser forces the molecules to perform synchronous cartwheels, which would continue forever if they didn’t eventually reach the walls of the experimental apparatus”, Trippel explains.

    The molecules travel an almost infinite distance compared with the period of their inversion – they have enough time to perform hundreds of thousands of cycles of this motion before they collide with the wall of the vacuum chamber. For experimenters, this offers some very tangible advantages: all they have to do in order to select a specific orientation of the molecular ensemble under scrutiny – in which the two orientations alternate regularly – is to select the appropriate moment in time behind the laser beam.

    This method not only works for the two lowest energy states, but in principle for all states of a linear molecule, as the researchers point out in their paper. “This targeted molecular choreography opens up new possibilities for holding ensembles of free molecules in the x-ray beam of a free electron laser in a controlled fashion, so that they can be investigated there,” says Küpper.

    Two-state wave packet for strong field-free molecular orientation; Sebastian Trippel, Terry Mullins, Nele L. M. Müller, Jens S. Kienitz, Rosario González-Férez and Jochen Küpper; Physical Review Letters, 2015; DOI: 10.1103/PhysRevLett.114.103003

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    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.

  • richardmitnick 3:00 am on March 12, 2015 Permalink | Reply
    Tags: , , , X-ray Technology   

    From New Scientist: “HIV’s hiding places at last revealed by simple scan” 


    New Scientist

    09 March 2015
    Clare Wilson

    (Image: medicalrf.com/Getty)

    It’s like using heat cameras to catch criminals on the run, but it finds HIV instead. A novel scanning technique is enabling researchers to pinpoint where in the body HIV is lurking.

    “This could really help with the research for a functional cure,” says Alan Winston of Imperial College London, who was not involved in the study.

    Today’s potent drug treatments can eradicate HIV from the blood, but the virus must survive elsewhere in the body, because it returns when people stop taking these drugs.

    It has been assumed that the virus hides out in immune cells at various “sanctuary sites”, either replicating very slowly or becoming completely dormant. Supporting this, biopsies reveal the virus in sites such as patches of immune tissue in the gut.

    Sanctuary sites

    One strategy to eradicate HIV completely might be to somehow wake up the hiding virus and then kill it. Research into this “kick and kill” strategy is ongoing, but little is known about which sanctuary sites are the most important, what the virus is doing there and whether existing drugs can reach the sites.

    Francois Villinger of Emory University in Atlanta and colleagues wondered if a PET scanning approach, which is also used to show the spread of cancer, could reveal the location of the virus. This idea was prompted by the discovery of an antibody that binds strongly to SIV, the monkey version of HIV.

    To test the idea, the team injected radioactive antibodies into three monkeys with SIV that were being treated with antiviral drugs. PET scanning, which can detect the location of radiation sources within the body, revealed the viral protein, called gp120, in a range of sites including the nose, lungs, gut, genitals and lymph nodes in the armpits and groin. The antibody could not get into the brain, however, which is thought to be another sanctuary site.

    The scans were not detailed enough to reveal which specific cells the virus protein was in, but tests after the monkeys were killed confirmed that the virus was present in the immune cells of the areas identified by the scan.

    Kick and kill

    Although the technique won’t show up a virus that is completely dormant, just being able to see where there is low viral replication is a major advance, says Winston. “It’s the first paper that has allowed us to visualise viral reservoirs.”

    The next step would be to develop antibodies that can recognise the gp120 protein made by the human strain of the virus. Scans made using these could aid researchers working on kick-and-kill strategies, and help investigate the rare cases where people seem to have been cured of HIV.

    This has been claimed for a handful of people who were given bone marrow transplants from donors whose immune cells are resistant to HIV, as well as for an infant who was given antiviral drugs straight after birth.

    Initially after that child – the so-called Mississippi baby – was taken off the drugs, there was no virus detectable in her blood, and her doctor claimed a cure. Unfortunately, after four years the virus returned and she had to restart drug treatment.

    The PET scanning technique could help in such cases, Villinger speculates, by revealing if the virus is present in sanctuary sites.

    See the full article here.

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  • richardmitnick 6:51 am on March 8, 2015 Permalink | Reply
    Tags: ETH Zurich, , X-ray Technology   

    From ETH Zurich: “An oscilloscope for MRI scanners” 

    ETH Zurich bloc

    ETH Zurich

    Anna Maltsev

    Skope co-founder Christoph Barmet demonstrates the Dynamic Field Camera in an MRI scanner. (Image: Skope)

    Take three driven physics wizards, an innovative business idea and lots of hard work, and what do you get? An ETH spin-off that could further advance both MRI research and medical diagnostics.

    “Actually, I really wanted to work in the insurance industry,” explains Christoph Barmet with a sheepish smile. Ten years, an ETH Silver Medal and a spin-off later, however, the 37-year old is now confident that his decision to focus on MRI technology instead of the insurance industry was the right one.

    MRI (magnetic resonance imaging) is defined as the form of magnetic resonance spectroscopy that produces cross-section images in any desired spatial plane, with excellent contrast particularly for tissue and internal organs in the human body. Based on MR images, accurate medical diagnosis and detailed exploration of individual body parts are possible. MRI is based on the fact that nuclei of hydrogen atoms within the human body can be excited by radio waves and as a result emit radio waves themselves. These waves are received by special coils, encoded with the help of magnetic fields and reconstructed into images using software.

    From students to entrepreneurs

    The former ETH student first got to know and love the technology while working on his master thesis. “In my thesis, I tried to make the heart vessels more visible through MRI. I found the technology so fascinating that I didn’t have to think twice when Professor Prüssmann offered me a doctoral dissertation in the MRI field,” recalls Barmet, who comes from Lucerne.

    At almost the same time that he finished, David Brunner and Bertram Wilm also completed their doctorates in MRI technology at ETH Zurich’s Institute for Biomedical Engineering. Barmet and Brunner both received an ETH Medal for their work. Beside their enthusiasm for MRI technology, a further passion united the three physics wizards: the dream of their own business. “In 2011, the time had come. Two years following our dissertation, our spin-off named Skope was born,” says Barmet, beaming. “We had long considered the product we wanted to produce and eventually decided on a measurement instrument to improve MRI images, dubbed Dynamic Field Camera.”


    More precise research results and early diagnosis

    In comparison, an MRI image acquired without the use of a Dynamic Field Camera and exhibiting some image artifacts (left) and a retrospectively corrected image using the new camera (right). (Image: Skope)

    This camera measures the encoding magnetic field dynamics present in the MR scanner with unprecedented accuracy and sensitivity, detecting encoding errors that are unavoidable even with the newest machines. These errors can be corrected either at the pre-emphasis level, in real time, or afterwards in the reconstruction of the data into images. Thus, more accurate, faster and more quantitative MRI images are possible.

    Meanwhile, the young entrepreneurs have also brought a second product, the Clip-on Camera, to market. It measures the dynamic magnetic fields during the actual MRI scan and allows a correction of the magnetic fields in real time; thereby perturbations are removed and the images turn more precise without involving additional signal post-processing.

    Potential users of this innovative device include primarily MRI researchers and manufacturers of MRI scanners. And despite the significant cost of about CHF 250,000 per device, the ETH graduates are pleased with sales so far. “Several research groups from around the world have bought our cameras, as well as Siemens, the largest manufacturer of MRI scanners. Philipps is currently testing it,” says Barmet. In the long run, the measurement devices will lead to more precise research results, and faster, more accurate medical diagnosis. For example, tumours can be detected earlier with the camera and blood flow measured more effectively than before. “If at some point the Dynamic Field Camera sensor technology were installed in every MRI scanner, it would mean faster, enhanced MRI diagnostics, and the realization of my dream” says Barmet.

    See the full article here.

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    ETH Zurich campus
    ETH Zurich is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zurich today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zurich, underlining the excellent reputation of the university.

  • richardmitnick 2:32 pm on February 27, 2015 Permalink | Reply
    Tags: , , X-ray Technology   

    From BNL: “A New X-Ray Microscope for Nanoscale Imaging” 

    Brookhaven Lab

    February 26, 2015
    Chelsea Whyte

    Yong Chu and Evgeny Nazaretski work in front of the new microscope they designed and installed at the Hard X-ray Nanoprobe beamline at NSLS-II.

    Delivering the capability to image nanostructures and chemical reactions down to nanometer resolution requires a new class of x-ray microscope that can perform precision microscopy experiments using ultra-bright x-rays from the National Synchrotron Light Source II (NSLS-II) at Brookhaven National Laboratory. This groundbreaking instrument, designed to deliver a suite of unprecedented x-ray imaging capabilities for the Hard X-ray Nanoprobe (HXN) beamline, brings researchers one step closer to the ultimate goal of nanometer resolution at NSLS-II, a U.S. Department of Energy Office of Science User Facility.

    The microscope manipulates novel nanofocusing optics called multilayer Laue lenses (MLL) — incredibly precise lenses grown one atomic layer at a time — which produce a tiny x-ray beam that is currently about 10 nanometers in size. Focusing an x-ray beam to that level means being able to see the structures on that length scale, whether they are proteins in a biological sample, or the inner workings of a fuel cell catalyst.

    The team of scientists who built this microscope aren’t stopping there; they are working toward making the focused x-ray beam spot even smaller in the future. The microscope they developed produces x-ray images by scanning a sample while collecting various x-ray signals emerging from the sample. Analysis of these signals helps researchers understand crucial information about the materials they are examining: density, elemental composition, chemical state, and the crystalline structure of the sample.

    Fluorescence and phase-contrast images of a platinum test pattern completed in the new microscope at the Hard X-ray Nanoprobe beamline. No image credit.

    Getting a clear image at this scale requires extremely high stability of the microscope to minimize vibrations and to reduce possible thermal drifts, changes in the microscope due to heat. It requires over twenty piezo motors — very fine motors that produce motion when electric currents are fed into piezo crystals — controlled down to nanometer-scale precision, crammed into a tight space about the size of a coffee maker, to meet its functionalities.

    “This instrument incorporates most recent developments in interferometric sensing, nanoscale motion, and position control. Recorded drifts of two nanometers per hour are unprecedented and set a new benchmark for x-ray microscopy systems,” said Evgeny Nazaretski, a physicist at NSLS-II who spearheaded the development of the microscope.

    Multi-layer Laue lens module inside the vacuum chamber of the microscope installed at the Hard X-ray Nanoprobe beamline at NSLS-II.

    After construction, the MLL module, a key component of the HXN x-ray microscope, was tested at the Diamond Light Source Beamline I-13L for extensive x-ray performance measurements. These measurements confirmed the stability and reliability of the new MLL system. Results are being published in the March issue of the Journal of Synchrotron Radiation.

    Hanfei Yan, a co-author of the paper, added, “We are grateful to our collaborators from Argonne National Laboratory who shared their technical expertise from the beginning of this project and also to collaborators from the Diamond Light Source who wholeheartedly supported the x-ray experiments.”

    “This instrument is a critical link connecting NSLS-II’s bright x-rays to unprecedented nanoscale x-ray imaging capabilities, which we believe will lead to many groundbreaking scientific discoveries”, stressed Yong Chu, the Group Leader of the Hard X-ray Nanoprobe Beamline at NSLS-II. The HXN beamline and the HXN x-ray microscope are currently being commissioned and will be available for user experiments later this year.

    This work is published in the Journal of Synchrotron Radiation.

    See the full article here.

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    BNL Campus

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

  • richardmitnick 4:14 pm on February 20, 2015 Permalink | Reply
    Tags: , , X-ray Technology   

    From SLAC: “New Programs Enhance SIMES Role in Studying Exotic New Materials” 

    SLAC Lab

    February 20, 2015

    Projects to Support Research in ‘Valleytronics’


    Two new three-year research projects are supporting the role of the Stanford Institute for Materials and Energy Sciences (SIMES) as a leading center for studying exotic new materials that could enable future innovative electronic and photonic applications. SIMES is a joint institute of Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory.

    “These awards are very important for SIMES,” said Tom Devereaux, a professor at SLAC and director of SIMES. “We have been establishing leadership in scientific areas that make SLAC unique. The awards significantly strengthen our core efforts in ultrafast science and quantum materials.”

    The two complementary projects will explore several theoretical and experimental aspects of an emerging area called “valleytronics.” In valleytronics, electrons move through the lattice of a two-dimensional semiconductor as a wave with two energy valleys whose characteristics can be used to encode information.

    Prime valleytronic materials are chalcogenides (pronounced cal-CAW-gin-eyeds), materials composed of a heavy metal atom and one or more atoms of oxygen, sulfur, selenium or tellurium. Many chalcogenides naturally form atom-scale layers that, under the right circumstances, result in special properties of interest to the SIMES researchers.

    “For example,” said SIMES researcher Yi Cui, “shining certain types of light onto some chalcogenides can control their electrons’ movements in ways that produce properties favorable for their use in efficient photodetectors, low-energy computer logic and data storage chips or quantum computers.”

    The SIMES researchers will perform theoretical calculations, make new nanomaterials and perform experiments in SLAC’s laboratories and DOE Office of Science User Facilities, including the Stanford Synchrotron Radiation Lightsource and the Linac Coherent Light Source. Their ultimate goal is to learn how to tune the materials to optimize their electronic properties.

    “SIMES and SLAC provide a wonderful combination of expertise in material synthesis, advanced characterization capabilities and theory, bringing together the key ingredients to make progress in this exciting new field,” remarked Stanford/SLAC Professor and SLAC Chemical Sciences Division Director Tony Heinz.

    One project, titled Induction and Dynamics of New States of Matter in Two-Dimensional Materials, is led by Devereaux, with co-investigators Zhi-Xun Shen, Aaron Lindenberg and Tony Heinz. It has received funding under the DOE’s “Scientific Discovery through Ultrafast Materials and Chemical Sciences” program. SLAC was the only DOE national lab chosen as a sole principal investigator in this program.

    The second project, Chalcogenide Nanomaterials, is led by SIMES researcher Yi Cui with co-investigators Harold Hwang, Shoucheng Zhang, Jun-Sik Lee and Hongtao Yuan. After the project’s success with last year’s seed funding, the DOE has established a core program at SLAC in this novel area.

    See the full article here.

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

  • richardmitnick 5:32 pm on February 13, 2015 Permalink | Reply
    Tags: , , , , , , X-ray Technology   

    From SLAC: “Scientists Get First Glimpse of a Chemical Bond Being Born” 

    SLAC Lab

    February 12, 2015

    Scientists have used an X-ray laser at the Department of Energy’s SLAC National Accelerator Laboratory to get the first glimpse of the transition state where two atoms begin to form a weak bond on the way to becoming a molecule.

    This illustration shows atoms forming a tentative bond, a moment captured for the first time in experiments with an X-ray laser at SLAC National Accelerator Laboratory. The reactants are a carbon monoxide molecule, left, made of a carbon atom (black) and an oxygen atom (red), and a single atom of oxygen, just to the right of it. They are attached to the surface of a ruthenium catalyst, which holds them close to each other so they can react more easily. When hit with an optical laser pulse, the reactants vibrate and bump into each other, and the carbon atom forms a transitional bond with the lone oxygen, center. The resulting carbon dioxide molecule detaches and floats away, upper right. The Linac Coherent Light Source (LCLS) X-ray laser probed the reaction as it proceeded and allowed the movie to be created. (SLAC National Accelerator Laboratory)

    This fundamental advance, reported Feb. 12 in Science Express and long thought impossible, will have a profound impact on the understanding of how chemical reactions take place and on efforts to design reactions that generate energy, create new products and fertilize crops more efficiently.

    “This is the very core of all chemistry. It’s what we consider a Holy Grail, because it controls chemical reactivity,” said Anders Nilsson, a professor at the SLAC/Stanford SUNCAT Center for Interface Science and Catalysis and at Stockholm University who led the research. “But because so few molecules inhabit this transition state at any given moment, no one thought we’d ever be able to see it.”

    Anders Nilsson, a professor at SLAC and at Stockholm University, explains how scientists used an X-ray laser to watch atoms form a tentative bond, and why that’s important.

    The experiments took place at SLAC’s Linac Coherent Light Source (LCLS), a DOE Office of Science User Facility. Its brilliant, strobe-like X-ray laser pulses are short enough to illuminate atoms and molecules and fast enough to watch chemical reactions unfold in a way never possible before.

    Researchers used LCLS to study the same reaction that neutralizes carbon monoxide (CO) from car exhaust in a catalytic converter. The reaction takes place on the surface of a catalyst, which grabs CO and oxygen atoms and holds them next to each other so they pair up more easily to form carbon dioxide.

    In the SLAC experiments, researchers attached CO and oxygen atoms to the surface of a ruthenium catalyst and got reactions going with a pulse from an optical laser. The pulse heated the catalyst to 2,000 kelvins – more than 3,000 degrees Fahrenheit – and set the attached chemicals vibrating, greatly increasing the chance that they would knock into each other and connect.

    The team was able to observe this process with X-ray laser pulses from LCLS, which detected changes in the arrangement of the atoms’ electrons – subtle signs of bond formation – that occurred in mere femtoseconds, or quadrillionths of a second.

    “First the oxygen atoms get activated, and a little later the carbon monoxide gets activated,” Nilsson said. “They start to vibrate, move around a little bit. Then, after about a trillionth of a second, they start to collide and form these transition states.”

    ‘Rolling Marbles Uphill’

    The researchers were surprised to see so many of the reactants enter the transition state – and equally surprised to discover that only a small fraction of them go on to form stable carbon dioxide. The rest break apart again.

    “It’s as if you are rolling marbles up a hill, and most of the marbles that make it to the top roll back down again,” Nilsson said. “What we are seeing is that many attempts are made, but very few reactions continue to the final product. We have a lot to do to understand in detail what we have seen here.”

    Theory played a key role in the experiments, allowing the team to predict what would happen and get a good idea of what to look for. “This is a super-interesting avenue for theoretical chemists. It’s going to open up a completely new field,” said report co-author Frank Abild-Pedersen of SLAC and SUNCAT.

    A team led by Associate Professor Henrik Öström at Stockholm University did initial studies of how to trigger the reactions with the optical laser. Theoretical spectra were computed under the leadership of Stockholm Professor Lars G.M. Pettersson, a longtime collaborator with Nilsson.

    Preliminary experiments at SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL), another DOE Office of Science User Facility, also proved crucial. Led by SSRL’s Hirohito Ogasawara and SUNCAT’s Jerry LaRue, they measured the characteristics of the chemical reactants with an intense X-ray beam so researchers would be sure to identify everything correctly at the LCLS, where beam time is much more scarce. “Without SSRL this would not have worked,” Nilsson said.

    The team is already starting to measure transition states in other catalytic reactions that generate chemicals important to industry.

    “This is extremely important, as it provides insight into the scientific basis for rules that allow us to design new catalysts,” said SUNCAT Director and co-author Jens Nørskov.

    Researchers from LCLS, Helmholtz-Zentrum Berlin for Materials and Energy, University of Hamburg, Center for Free Electron Laser Science, University of Potsdam, Fritz-Haber Institute of the Max Planck Society, DESY and University of Liverpool also contributed to the research. The research was funded by the DOE Office of Science, the Swedish National Research Council, the Knut and Alice Wallenberg Foundation, the Volkswagen Foundation and the German Research Foundation (DFG) Center for Ultrafast Imaging.

    See the full article here.

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

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