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  • richardmitnick 12:36 pm on May 23, 2016 Permalink | Reply
    Tags: , , , X-ray Technology   

    From SLAC: “Caught on Camera: First Movies of Droplets Getting Blown Up by X-ray Laser” 


    SLAC Lab

    May 23, 2016

    Details Revealed in SLAC Footage Will Give Researchers More Control in X-ray Laser Experiments

    Researchers have made the first microscopic movies of liquids getting vaporized by the world’s brightest X-ray laser at the Department of Energy’s SLAC National Accelerator Laboratory. The new data could lead to better and novel experiments at X-ray lasers, whose extremely bright, fast flashes of light take atomic-level snapshots of some of nature’s speediest processes.

    “Understanding the dynamics of these explosions will allow us to avoid their unwanted effects on samples,” says Claudiu Stan of Stanford PULSE Institute, a joint institute of Stanford University and SLAC. “It could also help us find new ways of using explosions caused by X-rays to trigger changes in samples and study matter under extreme conditions. These studies could help us better understand a wide range of phenomena in X-ray science and other applications.”


    Researchers have recorded the first movies of liquids getting vaporized by SLAC’s Linac Coherent Light Source (LCLS), the world’s brightest X-ray laser. The movies reveal new details that could lead to better and novel experiments at X-ray lasers. (SLAC National Accelerator Laboratory)
    Access mp4 video here .

    Liquids are a common way of bringing samples into the path of the X-ray beam for analysis at SLAC’s Linac Coherent Light Source (LCLS), a DOE Office of Science User Facility, and other X-ray lasers. At full power, ultrabright X-rays can blow up samples within a tiny fraction of a second. Fortunately, in most cases researchers can take the data they need before the damage sets in.


    Access the mp4 video here .

    The new study, published* today in Nature Physics, shows in microscopic detail how the explosive interaction unfolds and provides clues as to how it could affect X-ray laser experiments.

    Stan and his team looked at two ways of injecting liquid into the path of the X-ray laser: as a series of individual drops or as a continuous jet. For each X-ray pulse hitting the liquid, the team took one image, timed from five billionths of a second to one ten-thousandth of a second after the pulse. They strung hundreds of these snapshots together into movies.

    “Thanks to a special imaging system developed for this purpose, we were able to record these movies for the first time,” says co-author Sébastien Boutet from LCLS. “We used an ultrafast optical laser like a strobe light to illuminate the explosion, and made images with a high-resolution microscope that is suitable for use in the vacuum chamber where the X-rays hit the samples.”

    The footage shows how an X-ray pulse rips a drop of liquid apart. This generates a cloud of smaller particles and vapor that expands toward neighboring drops and damages them. These damaged drops then start moving toward the next-nearest drops and merge with them.


    This movie shows how a drop of liquid explodes after being struck by a powerful X-ray pulse from LCLS. The vertical white line at the center shows the position of the X-ray beam. The movie captures the first 9 millionths of a second after the explosion. (SLAC National Accelerator Laboratory)
    Access mp4 video here .

    In the case of jets, the movies show how the X-ray pulse initially punches a hole into the stream of liquid. This gap continues to grow, with the ends of the jet on either side of the gap beginning to form a thin liquid film. The film develops an umbrella-like shape, which eventually folds back and merges with the jet.


    Researchers studied the explosive interaction of X-ray pulses from LCLS with liquid jets, as shown in this movie of the first 9 millionths of a second after the explosion. (SLAC National Accelerator Laboratory)
    Access mp4 video here .

    Based on their data, the researchers were able to develop mathematical models that accurately describe the explosive behavior for a number of factors that researchers vary from one LCLS experiment to another, including pulse energy, drop size and jet diameter.

    They were also able to predict how gap formation in jets could pose a challenge in experiments at the future light sources European XFEL in Germany and LCLS-II, under construction at SLAC. Both are next-generation X-ray lasers that will fire thousands of times faster than current facilities.

    European XFEL Test module
    European XFEL Test module

    SLAC LCLS-II line
    SLAC LCLS-II line

    “The jets in our study took up to several millionths of a second to recover from each explosion, so if X-ray pulses come in faster than that, we may not be able to make use of every single pulse for an experiment,” Stan says. “Fortunately, our data show that we can already tune the most commonly used jets in a way that they recover quickly, and there are ways to make them recover even faster. This will allow us to make use of LCLS-II’s full potential.”

    The movies also show for the first time how an X-ray blast creates shock waves that rapidly travel through the liquid jet. The team is hopeful that these data could benefit novel experiments, in which shock waves from one X-ray pulse trigger changes in a sample that are probed by a subsequent X-ray pulse. This would open up new avenues for studies of changes in matter that occur at time scales shorter than currently accessible.

    Other institutions involved in the study were Max Planck Institute for Medical Research, Germany; Princeton University; and Paul Scherrer Institute, Switzerland. Funding was received from the DOE Office of Science; Max Planck Society; Human Frontiers Science Project; and SLAC’s Laboratory Directed Research & Development program.

    *Science paper:
    Liquid explosions induced by X-ray laser pulses

    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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  • richardmitnick 7:27 am on May 10, 2016 Permalink | Reply
    Tags: , , RIKEN SACLA, , X-ray Technology   

    From BNL: “Ultra-fast X-ray Lasers Illuminate Elusive Atomic Spins” 

    Brookhaven Lab

    May 9, 2016
    Justin Eure
    (631) 344-2347
    jeure@bnl.gov

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

    New x-ray technique reveals never-before-seen, trillionth-of-a-second magnetic fluctuations that transform the electronic and magnetic properties of materials.

    1
    Brookhaven Lab physicists Pavol Juhas, John Hill, Mark Dean, Yue Cao, and Vivek Thampy, all of the Condensed Matter Physics and Materials Science Department, except Hill, who is director of NSLS-II.

    A quick flash of light can make ordinary materials extraordinary, potentially inducing qualities such as the perfect efficiency of superconductivity even at room temperature. But these subatomic transformations are infamously fleeting—they vanish in just trillionths of a second.

    Now, an international team of scientists has used synchronized infrared and x-ray laser pulses to simultaneously manipulate and reveal the ultra-fast magnetic properties of this promising quantum landscape. The rapid, light-driven switching between magnetic states, explored here with unprecedented precision, could one day revolutionize the reading and writing of data in computers and other digital devices.

    The study, published* May 9, 2016, in the journal Nature Materials, was led by scientists at the U.S. Department of Energy’s Brookhaven National Laboratory and included researchers from the U.S., China, Germany, Japan, Spain, and the UK.

    “We developed a way to reveal light-induced femtosecond magnetic dynamics in as yet unseen detail,” said Mark Dean, a physicist at Brookhaven Lab and lead author on the study. “This brings us closer to perfecting a recipe for manipulating these materials on ultra-fast time scales.”

    This novel x-ray technique, called time-resolved resonant inelastic scattering, revealed the subtle spin correlations, which travel as waves through the material and define its magnetic properties. Crucially, they behaved differently between two- and three-dimensional spaces when sparked by an infrared laser pulse.

    “Within a two-dimensional atomic plane, the novel state lasted just a few picoseconds,” said Brookhaven physicist and study coauthor Yue Cao. “But three-dimensional correlations also cross between planes, and these took hundreds of picoseconds to vanish—on this scale, that difference is tremendous. It is enormously exciting to help pioneer a new technique and see it succeed.”

    The bulk of the experimental work relied on the powerful and precise x-ray lasers available at SLAC National Accelerator Laboratory’s Linac Coherent Light Source, a DOE Office of Science User Facility, and the SACLA facility in Japan.

    SLAC/LCLS
    SLAC/LCLS

    SACLA Free-Electron Laser Riken Japan
    SACLA Free-Electron Laser Riken Japan

    Doping with light

    To introduce novel magnetic and electronic qualities, scientists often use a technique called chemical doping to augment the atomic configuration of a material. Electrons can be meticulously added or removed, but the process is permanent.

    “We wanted to access similar states transiently, so we used photo-doping,” Dean said. “A laser pulse supplies the needed photons, which changes the electron and spin configuration in the sample—the same spins thought to be responsible for phenomena like superconductivity. Moments later, the material returns to its native state.”

    In this work, the scientists used a strontium-iridium-oxygen compound (Sr2IrO4), selected for its strong magnetic interactions. Manipulating spin in the material was relatively easy—the real challenge was catching it in motion.

    Bright, fast flashes

    The collaboration turned to two powerful photon sources: the LCLS and SACLA, both uniquely capable of illuminating a quantum spin wave mid-stride. Both facilities can produce x-ray pulses with extremely short duration and high brightness.

    “Knowing that these facilities could produce fast and accurate enough laser pulses inspired this entire collaboration,” said study coauthor John Hill, the director of Brookhaven Lab’s National Synchrotron Light Source II, another DOE Office of Science User Facility.

    BNL NSLS-II Interior
    BNL NSLS-II

    For the experiment, an initial infrared laser pulse struck the layered Sr2IrO4 compound, destroying the native magnetic state. For a brief moment, the electrons inside the material formed spin waves that rippled through the material and radically changed its electronic and magnetic properties. Trillionths of a second later, an x-ray pulse followed and bounced off those emergent waves. By measuring the change in both momentum and the angles of diffraction, the scientists could deduce the transient electronic and magnetic qualities.

    This specific process of bouncing and tracking x-rays, called resonant inelastic x-ray scattering (RIXS), was also pioneered by members of this collaboration to explore similar phenomena in condensed matter systems. The new research builds on that to include time-resolved data points.

    “Beyond the remarkable capabilities of LCLS and SACLA to supply ultra-short femtosecond x-ray pulses, the challenge we were facing was how to detect the response of the spins,” said study coauthor Xuerong Liu from the Institute of Physics in Beijing. “That is, we needed a specialized x-ray detection system or ‘camera.'”

    The scientists developed a highly specialized RIXS spectrometer, which used millimeter-sized silicon crystals to measure the exact energy of the rebounding x-rays.

    The data revealed a clear difference in the propagation and timescale of the magnetic phenomena, with the inter-layer correlations taking hundreds of times longer to recover than those within each layer.

    “The findings match theoretical expectations, which is encouraging, but more importantly they demonstrate the strength and precision of this technique,” said collaborator Michael Först of the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany. “We can now dive deeper into the mechanism and think of strategies to fine-tune the control of magnetic properties with light.”

    Next, the scientists plan to explore optical pulses at even longer wavelengths, which will shift atoms within the material without directly exciting the electrons and spins. That work may help reveal the native magnetic coupling within the material, which in turn will clarify how to best break that coupling and toggle between different electronic and magnetic states.

    The research was funded in part by the DOE’s Office Science (BES), which supported experimentation at LCLS.

    *Science paper:
    Ultrafast energy- and momentum-resolved dynamics of magnetic correlations in the photo-doped Mott insulator Sr2IrO4

    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.
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  • richardmitnick 10:09 am on May 6, 2016 Permalink | Reply
    Tags: , , Supercooled Cavities for Particle Acceleration, X-ray Technology   

    From BNL: “Supercooled Cavities for Particle Acceleration” 

    Brookhaven Lab

    May 3, 2016
    Ariana Tantillo

    Very low temperatures support research at Brookhaven National Laboratory’s National Synchrotron Light Source II

    BNL NSLS-II Building
    BNL NSLS-II Building

    BNL NSLS-II Interior
    BNL NSLS-II Interior

    1
    A superconducting radio-frequency cryomodule installed in the NSLS-II ring. No image credit.

    When you think about the coldest places on Earth, the National Synchrotron Light Source II (NSLS-II), a U.S. Department of Energy (DOE) Office of Science User Facility located at the DOE’s Brookhaven National Laboratory, probably doesn’t come to mind. But accelerating electrons around the half-mile-long ring of NSLS-II at nearly the speed of light requires some extremely cold temperatures, hundreds of degrees below the freezing point of water.

    Supercool temperatures mean super cool science research can go on.

    A continuous flow of electrons

    As electrons circle around NSLS-II’s ring, they emit extremely bright X-rays that scientists use to image materials, such as soil samples, batteries, and biological proteins. “The images are not necessarily photographs, but spectrum, absorption lines, or diffraction patterns,” explained James Rose, head of the Radio Frequency Systems Group for NSLS-II.

    By studying the fluorescence, diffraction, scattering, and absorption of X-rays, scientists can uncover a material’s atomic structure, which gives rise to its chemical, electronic, and structural properties. From examining soil samples to understand the uptake of chemical runoff, to watching in real time as batteries operate to discover where and how materials inside break down, to examining the structure of biological proteins to help design new drugs for treating disease, scientists at NSLS-II probe the inner workings of various kinds of materials.

    In producing these X-rays, the electrons lose energy and slow down. For the electrons to continue generating the high-power X-ray beams used by scientists from around the world to image materials, this energy must be replenished.

    At NSLS-II, electrons gain this energy by passing through two hollow metal (niobium) chambers called radio-frequency (RF) cavities that contain an electromagnetic field. The electric field transfers energy to the electrons, propagating them along the ring. “An RF cavity is a resonator like an organ pipe or guitar string,” said Rose. “Our cavities are tuned to a particular frequency such that an electron traveling around the ring passes through the cavity at the same phase each trip, and gains the same energy per pass as it loses energy to synchrotron radiation, or light. Giving energy to the electron at just the right time increases its energy, much like someone pushing a child on a swing.”

    When cooled to an extremely low, or cryogenic, temperature, the niobium in the RF cavity becomes superconducting—that is, it loses nearly all resistance to an electric current. As a result, electrons can flow freely through the cavities. If niobium were conducting electricity as it would at room temperature, there would be a large resistance to the flow of electrons. When electron flow is resisted, the electrical energy that moves the electrons is converted into heat energy—a waste product. Without this resistance, electricity can be delivered to the cavity much more efficiently.

    “If the cavities were not superconducting, almost seven times more energy would be required to keep the electrons flowing to produce high-intensity X-ray beams,” said Rose.

    The superconductivity not only reduces energy loss in the cavities but it also provides for electron beam stability.

    “Because we don’t need to worry about keeping resistive losses low, we can design the cavities with a large aperture that allows resonant frequencies above the cavity’s tuned frequency to leak out of the cavity into absorbers that damp, or reduce the amplitude of, the higher-frequency oscillations. If these higher frequencies were not damped, they would add and subtract energy from the beam out of sequence. That’s like pushing the child on the swing randomly, causing the swing to slow down or stopping the child short at the highest speed,” explained Rose.

    Supercooled cavities

    At NSLS-II, the RF cavities are continuously immersed in liquid helium, which, with the help of liquid nitrogen, cools niobium to its superconducting state. The cavities are installed within cryomodules, which are essentially vacuum-insulated containers like thermos bottles that maintain the ultra-cold temperatures of the liquid helium to allow for near-zero electrical resistance within the RF cavity.

    2
    Brookhaven Lab staff members (left to right) James Rose, John Gosman, and William Gash with one of the two electron bunch–lengthening radio-frequency cavities that will be installed at the National Synchrotron Light Source II (NSLS-II). By reducing the number and intensity of collisions between electrons circling the NSLS-II electron storage ring, these cavities will help prevent electron beam loss and thus extend the lifetime of the beams used to conduct experiments.

    “The only way to make liquid helium from gaseous helium is to cool it down,” explained Rose. “Because nitrogen is inexpensive as compared to helium, we use liquid nitrogen to precool the helium from room temperature down to liquid nitrogen’s boiling point of 321 degrees below zero. From there, we cool the helium down to approximately minus 450 degrees Fahrenheit.”

    Cooling helium gas into a liquid is a multistep process. First, the gas is squeezed in compressors. As the gas molecules are forced into a smaller volume, the pressure and temperature of the gas rise. The gas is then fed into an insulated enclosure called a cold box, where three fast-moving expansion turbines liquefy the gas by reducing its pressure, causing the gas molecules to spread apart. This rapid expansion causes the gas to cool and a portion of it to liquefy.

    “The cold box is the heart of the cryogenic plant,” said William Gash, a cryogenics engineer in Brookhaven’s Utilities Group. “Its turbines rotate at many thousands of revolutions per second, as compared to a car, which operates in revolutions per minute.”

    Once liquefied, the helium is stored in a large vacuum-insulated container and distributed through insulated piping and control valves directly into the cryomodules to surround the RF cavities.

    The remaining cooled gas is returned to the cold box, where it flows through heat exchangers to precool the incoming high-pressure gas before being sent to the compressor to start the cycle again.

    “The cryogenics plant is a closed-loop system,” explained Gash. “All of the helium is recovered. Even in the event of an emergency, we have a recovery system in place to ensure the supply is retrieved.”

    Longer-lived beams

    In the next five years or so, additional superconducting RF cavities and valves will be installed.

    “This installation will provide the RF power needed to support more beams and thus more experiments at NSLS-II,” said Rose.

    Two of the cavities will be electron bunch–lengthening cavities, which “lengthen” the bunches, or groups, of electrons traveling around the ring.

    In dense bunches, electrons circling the ring undergo collisions with other electrons in the bunch. “Imagine dancers that bump into one another on a crowded dance floor,” said Rose.

    These collisions scatter the electrons, causing some electrons to be ejected from the bunch. Eventually, these ejected electrons hit the beam pipe and lose their energy to radiation. “Some dancers leave the dance floor and go home,” said Rose. “By lengthening the electron bunches (increasing the size of the dance floor), we can reduce the density of electrons (spreading people out on the dance floor), thereby reducing the number and intensity of the collisions. Ultimately, these new cavities will extend the lifetime of the beams.”

    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.
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  • richardmitnick 8:38 am on May 6, 2016 Permalink | Reply
    Tags: , , , X-ray Technology   

    From DESY: “High-speed camera snaps biosensor’s rapid reaction to light” 

    DESY
    DESY

    X-ray study reveals ultrafast dynamics of photoactive yellow protein

    1
    Inner structure of the photactive yellow protein 800 femtoseconds after the trans-to-cis isomerisation has been initiated by an ultrafast blue laser. The chromophore binding pocket is cut open and the chromophore itself is highlighted by the bulls eye. Credit: Marius Schmidt/University of Wisconsin-Milwaukee

    Using a high-speed X-ray camera, an international team of scientist including researchers from DESY has revealed the ultrafast response of a biosensor to light. The study, published* in the US journal Science, shows light-driven atomic motions lasting just 100 quadrillionths of a second (100 femtoseconds). The technique promises insights into the ultrafast dynamics of various light sensitive biomolecules responsible for important biological processes like photosynthesis or vision.

    The team lead by Marius Schmidt from the University of Wisconsin, Milwaukee used the LCLS X-ray laser at SLAC National Accelerator Laboratory in the U.S. to look at the light-sensitive part of a protein called photoactive yellow protein, or PYP.

    SLAC/LCLS
    SLAC/LCLS

    It functions as an “eye” in purple bacteria, helping them sense blue light and stay away from light that is too energetic and potentially harmful.

    For their investigation, the scientists sent a stream of tiny PYP crystals into a sample chamber. There, each crystal was struck by a flash of optical laser light and then, almost immediately after, an X-ray pulse was used to interrogate the protein’s structural response to the light at the atomic level. The structure is determined indirectly from the intricate pattern of X-ray light scattered from the crystal. By varying the time between the two pulses, scientists were able to see how the protein morphed over time. “By placing the various obtained molecular structures in order of the time delay between the optical and X-ray flashes we obtain a molecular movie of the reaction as it evolves from the first step at 100 femtoseconds to several thousand femtoseconds,” explained the first author of the paper, Kanupriya Pande, also from the University of Wisconsin and now at the Center for Free-Electron Laser Science CFEL at DESY.

    “The absorption of light leaves PYP in an excited state from which it relaxes very quickly,” explained Schmidt, the study’s principal investigator. “It does so by rearranging its atomic structure in what is known as trans-to-cis isomerisation. We’re the first to succeed in taking real-time snapshots of this type of reaction.” This type of isomerisation is also what gives vision – in that case the retinal chromophore undergoes a cis-to-trans isomerisation that ultimately leads to neuronal excitation in the eye.

    “We were able to obtain detailed structures at incredibly short time points after the initial absorption event by taking flash X-ray snapshots with the world’s brightest X-ray source,” said co-author Henry Chapman from CFEL at DESY. But, as Pande pointed out, “these are very challenging experiments, where we needed considerable innovation to assign the correct time stamps to hundreds of thousands of X-ray patterns.”

    The researchers had already studied light-induced structural changes in PYP at LCLS before, revealing atomic motions as fast as 10 billionths of a second (10 nanoseconds). By tweaking their experiment with a faster optical laser and better timing tools and sorting, they were now able to improve their speed limit 100,000 times and capture reactions in the protein that are 1,000 times faster than any seen in an X-ray experiment before.

    “The new data show for the first time how the bacterial sensor reacts immediately after it absorbs light,” says co-author Andy Aquila from SLAC. “The initial response, which is almost instantaneous, is absolutely crucial because it creates a ripple effect in the protein, setting the stage for its biological function.”

    The technique could prove valuable to unveil a number of other important ultrafast light-driven processes, for instance how visual pigments in the human eye respond to light, and how absorbing too much of it damages them; how photosynthetic organisms turn light into chemical energy, a process that could serve as a model for the development of new energy technologies; or how atomic structures respond to light pulses of different shape and duration, an important first step toward controlling chemical reactions with light.

    Together with the University of Wisconsin, Milwaukee, SLAC and DESY, the following institutions were involved in this study: Imperial College London, the University of Jyväskylä in Finland, Arizona State University, Max Planck Institute for Structure and Dynamics of Matter in Hamburg, State University of New York at Buffalo, University of Chicago, Lawrence Livermore National Laboratory and University of Hamburg.

    *Science paper:
    Femtosecond structural dynamics drives the trans/cis isomerization in photoactive yellow protein

    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.

     
  • richardmitnick 8:31 am on May 3, 2016 Permalink | Reply
    Tags: , , X-ray Technology   

    From XFEL: “World’s most precise mirror arrives in Hamburg” 

    XFEL bloc

    European XFEL

    03 May 2016

    The first of several ultraflat mirrors is a milestone of a rigorous research and development effort.

    A 95-cm long mirror that is more precise than any other yet built was delivered to European XFEL, an X-ray laser research facility that is under construction in the Hamburg area of Germany. The mirror is superflat and does not deviate from its surface quality by more than one nanometre, or a billionth of a metre. It is the first of several of its kind needed for the European XFEL. Each will be essential to the facility’s operation, enabling scientists from around the globe to reliably use the world’s brightest X-ray laser light for research into ultrafast chemical processes, complex molecular structures, and extreme states of matter. The precision of the European XFEL mirror is equivalent to a 40-km long road not having any bumps larger than the width of a hair. The mirror’s production is the culmination of a long research and development process involving several institutes and companies in Japan, France, Italy, and Germany.

    The mirror body, with a 95 cm long and 5.2 cm wide reflective face, is made from a single crystal of silicon that was crafted by industrial partners in France and Italy. In order to polish a mirror of the required length to European XFEL’s nanometre specification, the optics company JTEC in Osaka, Japan, used a new polishing method using a pressurized fluid bath capable of stripping atom-thick layers off of the crystal. This development required the construction of a brand-new facility that would be able to meet the exceptional demands from the European XFEL, while also expanding the company’s ability to serve other, similar facilities, such as the LCLS in the U.S. and SwissFEL in Switzerland.

    SLAC/LCLS
    SLAC/LCLS

    SwissFEL Paul Sherrer Institute
    SwissFEL Paul Sherrer Institute

    The polishing technique alone took nearly a year to develop to a point where the extreme quality could be reached.

    1
    European XFEL scientist Maurizio Vannoni inspects the delivered superflat mirror, which does not deviate from a perfect surface by more than a billionth of a metre. European XFEL

    “When we first started working on these optics, we were looking for something that simply didn’t exist at anywhere near this precision”, says Harald Sinn, who leads the European XFEL X-Ray Optics group. “Now we have the first ever mirror at this extreme specification.”

    The mirrors have to be so precise because of the laser properties of the X-rays at the European XFEL. These properties are essential to clearly image matter at the atomic level. Previously, European XFEL simulations had shown that any distortions in the mirrors greater than one nanometre would cause the properties of the laser spot on the sample to be degraded.

    Mirrors of this series will be used to deflect the X-rays by up to a few tenths of a degree into the European XFEL’s six scientific instruments in its underground experiment hall in the town of Schenefeld. This is done because the instruments, which are parallel to each other, will eventually be able to operate in parallel, enabling scientists to have greater access to the facility and its unique X-ray light. Additionally, similar mirrors will focus the X-ray light within some of the facility’s instruments.

    However, the particular mirror that was delivered is needed for filtering the light generated by the facility to only the kind needed for experiments. Within the European XFEL’s X-ray laser light-generating structures, called undulators, some undesirable wavelengths of light are produced. A set of these superflat mirrors will be arranged after each undulator in the facility’s underground tunnels, and the position of each mirror allows for only the desired wavelength of laser light to continue towards the experiment hall. The undesirable wavelengths of light are more energetic and pass through the mirror instead of reflecting, ending up in an adjacent absorber made of boron carbide and tungsten.

    The mirror will now be measured at European XFEL and Helmholtz Zentrum Berlin for additional verification of its specifications. Three more mirrors of the same type are due to arrive at European XFEL in May.

    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 3:41 pm on April 26, 2016 Permalink | Reply
    Tags: , , X-ray Technology   

    From LBL: “Seeing Atoms and Molecules in Action with an Electron ‘Eye’ “ 

    Berkeley Logo

    Berkeley Lab

    April 26, 2016
    Glenn Roberts Jr.
    510-486-5582
    geroberts@lbl.gov

    1
    Daniele Filippetto, a Berkeley Lab scientist, works on the High-Repetition-rate Electron Scattering apparatus (HiRES), which will function like an ultrafast electron camera. HiRES is a new capability that builds on the Advanced Photo-injector Experiment (APEX), a prototype electron source for advanced X-ray lasers. (Roy Kaltschmidt/Berkeley Lab)

    A unique rapid-fire electron source—originally built as a prototype for driving next-generation X-ray lasers—will help scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) study ultrafast chemical processes and changes in materials at the atomic scale. This could provide new insight in how to make materials with custom, controllable properties and improve the efficiency and output of chemical reactions.

    This newly launched setup, dubbed HiRES (for High Repetition-rate Electron Scattering apparatus), will function like an ultrafast electron camera, potentially producing images that can pinpoint defects and their effects, track electronic and superconducting properties in exotic materials, and detail chemical reactions in gases, liquids and biological samples that are difficult to study using more conventional, X-ray-based experiments.

    The new research tool produces highly focused electron bunches, each containing up to 1 million electrons. The electrons stream at a rate of up to 1 million bunches per second, or 1 trillion electrons per second.

    Electrons will be used as a fast camera shutter to capture snapshots of samples as they change over femtoseconds, or quadrillionths of a second. An initial laser pulse will trigger a reaction in the sample that is followed an instant later by an electron pulse to produce an image of that reaction.

    HiRES delivered its first electron beam March 28 and experiments are set to begin in May.

    Daniele Filippetto, a Berkeley Lab scientist who is leading HiRES, has for much of his scientific career focused on building electron sources, also called “electron guns,” that can drive advanced X-ray lasers known as “free-electron lasers.” These electron guns are designed to produce a chain of high-energy electron pulses that are accelerated and then forced by powerful magnetic fields to give up some of their energy in the form of X-ray light.

    SACLA Free-Electron Laser Riken Japan
    SACLA Free-Electron Laser Riken Japan

    Free-electron lasers have opened new frontiers in studying materials and chemistry at the nanoscale and beyond, and Filippetto said he hopes to pave new ground with HiRES, too, using a technique known as “ultrafast electron diffraction,” or UED, that is similar to X-ray diffraction.

    In these techniques, a beam of X-rays or electrons hits a sample, and the scattering of X-rays or electrons is collected on a detector. This pattern, known as a diffraction pattern, provides structural information about the sample. X-rays and electrons interact differently: electrons scatter from a sample’s electrons and the atoms’ nuclei, for example, while X-rays scatter only from the electrons.

    The unique electron gun that Filippetto and his team are using is a part of Berkeley Lab’s APEX (Advanced Photo-injector EXperiment), which has served as a prototype system for LCLS-II, a next-generation X-ray laser project underway at SLAC National Acceleratory Laboratory in Menlo Park, Calif. Berkeley Lab is a member of the LCLS-II project collaboration.

    “The APEX gun is a unique source of ultrafast electrons, with the potential to reach unprecedented precision and stability in timing—ultimately at or below 10 femtoseconds,” Filippetto said. “With HiRES, the time resolution will be about 100 femtoseconds, or the time it takes for chemical bonds to form and break. So you can look at the same kinds of processes that you can look at with an X-ray free-electron laser, but with an electron eye.”

    He added, “You can see the structure and the relative distances between atoms in a molecule changing over time across the whole structure. You need fewer electrons than X-rays to get an image, and in principal there can be much less damage to the sample with electrons.”

    2
    This computerized rendering shows the layout of the HiRES ultrafast electron diffraction beamline, which is located in the domed Advanced Light Source building at Berkeley Lab. At left (on blue base) is APEX, the electron source for HiRES. (Courtesy of Daniele Filippetto/Berkeley Lab)

    Filippetto in 2014 received a five-year DOE Early Career Research Program award that is supporting his work on HiRES. The work is also supported by the Berkeley Lab Laboratory Directed Research and Development Program.

    Already, Berkeley Lab has world-class research capabilities in other electron-beam microscopic imaging techniques, in building nanostructures, and in a range of X-ray experimental techniques, Filippetto noted. All of these capabilities are accessible to the world’s scientists via the lab’s Molecular Foundry and Advanced Light Source (ALS).

    “If we couple all of these together with the power of HiRES, then you basically can collect full information from your samples,” he said. “You can get static images with subatomic resolution, the ultrafast structural response, and chemical information about a sample—in the same lab and in the same week.”

    3
    A view of the HiRES ultrafast electron diffraction (UED) beamline at Berkeley Lab’s APEX. (Roy Kaltschmidt/Berkeley Lab)

    Filippetto has a goal to improve the focus of the HiRES electron beam from microns, or millionths of a meter in diameter, to the nanometer scale (billionths of a meter), and to also improve the timing from hundredths of femtoseconds to tens of femtoseconds to boost the quality of the images it produces and also to study even faster processes at the atomic scale.

    Andrew Minor, director of the Molecular Foundry’s National Center for Electron Microscopy said he is excited about the potential for HiRES to ultimately study the structure of single molecules and to explore the propagation of microscopic defects in materials at the speed of sound.

    “We want to study nanoscale processes such as the structural changes in a material as a crack moves through it at the speed of sound,” he said. Also, the timing of HiRES may allow scientists to study real-time chemical reactions in an operating battery, he added.

    “What is really interesting to me is that you can potentially focus the beam down to a small size, and then you would really have a system that competes with X-ray free-electron lasers,” Minor said, which opens up the possibility of electron imaging of single biological particles.

    He added, “I think there is a very large unexplored space in terms of using electrons at the picosecond (trillionths of a second) and nanosecond (billionths off a second) time scales to directly image materials.”

    There are tradeoffs in using X-rays vs. electrons to study ultrafast processes at ultrasmall scales, he noted, though “even if the capabilities are similar, it’s worth pursuing” because of the smaller size and lesser cost of machines like APEX and HiRES compared to X-ray free-electron lasers.

    Scientists from Berkeley Lab’s Materials Sciences Division and from UC Berkeley will conduct the first set of experiments using HiRES, Filippetto said, including studies of the structural and electronic properties of single-layer and multilayer graphene, as well as other materials with semiconductor and superconductor properties.

    There are also some clear uses for HiRES in chemistry and biology experiments, Filippetto noted. “The idea is to push things to see ever-more-complicated structures and to open the doors to all of the possible applications,” he said.

    There are plans to forge connections between HiRES and other lab facilities, like the ALS, where HiRES is located, and the lab’s National Center for Electron Microscopy at the Molecular Foundry.

    “Already, we are working with the microscopy center on the first experiments,” Filippetto added. “We are adapting the microscope’s sample holder so that one can easily move samples from one instrument to another.”

    Filippetto said there are discussions with ALS scientists on the possibility of gathering complementary information from the same samples using both X-rays from the ALS and electrons from HiRES.

    “This would make HiRES more accessible to a larger scientific community,” he added.

    The Molecular Foundry and Advanced Light Source are DOE Office of Science User Facilities. HiRES is supported by the U.S. Department of Energy Office of Science.

    LBL Advanced Light Source
    LBL Advanced Light Source

    4
    A labeled diagram showing the components of the HiRES beamline at Berkeley Lab. (Courtesy of Daniele Filippetto/Berkeley Lab)

    See the full article here .

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  • richardmitnick 11:39 am on April 18, 2016 Permalink | Reply
    Tags: , , , , X-ray Technology, XFEL   

    From LC: “From metal sheet to particle accelerator (Part 1of 3)” 

    Linear Collider Collaboration header
    Linear Collider Collaboration

    14 April 2016
    Ricarda Laasch

    1
    Cavity production at Zanon in Italy. Image: DESY, Heiner Müller-Elsner

    In September 2015, the 50th accelerator module for the X-ray free-electron laser European XFEL was tested at DESY. One hundred accelerator modules are needed for the two-kilometre-long electron accelerator of the X-ray free-electron laser. Each module consists of eight cavities, the actual accelerating structures. This is the first of a three-part series (first published in DESY inForm) about how these technological masterpieces are manufactured. Part 1 is about cavities; their production has now been completed.

    Two companies have been commissioned with the cavity production: Research Instruments (RI) in Germany and Zanon in Italy. “This is the first time we have ordered cavities virtually ready for operation from industry,” emphasises Axel Matheisen who together with Waldemar Singer leads a team of engineers and technicians at DESY supervising these firms. In the past, industry had only carried out the mechanical production steps. “For that reason, our greatest concern was whether we would manage to convey the necessary knowledge in a way that the companies are able to produce complete cavities,” says Mattheisen. The tested cavities prove that this knowledge transfer worked perfectly.

    At the beginning of the long production process, there is a square niobium sheet with an edge length of 26.5 centimetres and a thickness of 2.8 millimetres. For the construction of the accelerator, the purity of 14 700 sheets is tested at DESY before being dispatched to the two production firms. There, the sheets are deep-drawn to so-called half cells which gives them the appropriate shape for further processing. A stamp is used to obtain the required hollow pattern … the cavity.

    Subsequently, 18 half cells are welded together to form one cavity. Since niobium oxidises very easily, this cannot be done with a flame. Instead, the half cells are welded together with an electron beam in a vacuum chamber. The advantage: this procedure is very clean. For this reason, the nine-cell cavity must be protected from new contamination during further processing.

    For accelerator operation, the quality of the cavity’s inner surface is extremely important. It must not only be hyper clean but also exceptionally smooth. “In the past, the cavities were delivered to us and we did the rest. This went quite well with ten or occasionally with 30 cavities per year. But it was clear that this would not be possible with some 100 cavities per year,” Mattheisen says. For the construction of the European XFEL, the firms had to learn to carry out the surface treatment according to the “DESY recipe” and to work in a nearly dust-free cleanroom. “This was completely new for them and therefore, communication was ex- tremely important,” Mattheisen points out. The most important steps in this process are pickling, baking, tuning, dressing and rinsing.

    For pickling, various different acid mixtures are lled into the cavity. The acid reacts with the metal surface of the cavity and removes processing residues and polishes the surface. The acids’ mixture ratio and the extent of the pickling procedure have been optimised during many years of research at DESY. Baking follows pickling: the cavity is heated at 800 degrees centigrade for several hours in a humidity-free vacuum environment. During this treatment, tensions in the metal originating from shaping and welding are released and the ne crystal structures of niobium are newly arranged.

    After getting out of the oven, the cavity is tuned. In order to accelerate particles during operation, electromagnetic fields are induced to oscillate in the cavity and, eventually, the oscillation will turn into resonance. For this aim, however, the shape of each cavity cell must be exactly tuned to the accelerator frequency of 1.3 gigahertz. In the process of tuning, the resonance frequency is measured and when it diverges from the desired frequency, the cavity must be retuned. For this purpose, the cavity shells are pressed and pushed accordingly. Slight shape alterations can signi cantly improve the resonance.

    The next step is dressing: the cavity is welded into its helium tank. Liquid helium cools down the cavity in operation to minus 271 degrees centigrade to generate superconductivity and remove heat. Subsequently, a total of four antennae are to be mounted onto the cavity. One of it feeds the electromagnetic field into the cavity, the others recover it at the opposite end. “Doing this kind of mounting in a cleanroom is not the average, not even for industry,” says Mattheisen. “It is not usual work to set bolts and nuts in a cleanroom; it requires practice and, above all, patience since all procedures must be carried out slowly.”

    The production is completed with rinsing: the inner surface of the cavity is sprayed off for some hours with high pressure ultrapure water of 100 bar. Now, the cavity with a vacuum inside leaves the cleanroom. Packed in a special case, it is shipped to DESY by lorry. However, the cavity is not yet ready for installation into a European XFEL module. It will first have to demonstrate its qualities.

    See the full article here .

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    The Linear Collider Collaboration is an organisation that brings the two most likely candidates, the Compact Linear Collider Study (CLIC) and the International Liner Collider (ILC), together under one roof. Headed by former LHC Project Manager Lyn Evans, it strives to coordinate the research and development work that is being done for accelerators and detectors around the world and to take the project linear collider to the next step: a decision that it will be built, and where.

    Some 2000 scientists – particle physicists, accelerator physicists, engineers – are involved in the ILC or in CLIC, and often in both projects. They work on state-of-the-art detector technologies, new acceleration techniques, the civil engineering aspect of building a straight tunnel of at least 30 kilometres in length, a reliable cost estimate and many more aspects that projects of this scale require. The Linear Collider Collaboration ensures that synergies between the two friendly competitors are used to the maximum.

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  • richardmitnick 9:16 am on April 14, 2016 Permalink | Reply
    Tags: , , X-ray Technology   

    From DESY: “First user operation at FLASH2” 

    DESY
    DESY

    1
    FLASH is the first X-ray laser worldwide which can serve experiments at two beamlines at the same time

    DESY/FLASH
    DESY/FLASH

    Since Friday, 8 April at 12:14 h FLASH is running in parallel operation for two user experiments, one in the experimental hall “Albert Einstein” (FLASH1) and one in the new hall “Kai Siegbahn” (FLASH2). First official FLASH2 users are the researchers around Sven Toleikis and Andreas Przystawik at beamline FL24 who focus the FLASH2 pulses with the help of a multilayer mirror onto rare gas clusters and study the fluorescence of the resulting nanoplasma as a function of cluster size.

    Right after the successful start last Friday the first record for this doubled user operation was set: On Saturday, FLASH delivered 4000 pulses per second with up to 140 micro joule (µJ) per pulse to an experiment of Mark Dean et al. (Brookhaven National Laboratory, New York) at FLASH1 beamline PG1 and in parallel 110 pulses per second with about 100 micro joule each for FLASH2 making it a successful start at both ends.

    The second free-electron laser line, FLASH2, has been realized from 2011 to 2015. Soon after the first successful generation of extremely intense FEL radiation on FLASH2 in August 2014, parallel operation of the two soft X-ray free-electron lasers, FLASH1 and FLASH2, has been established. Now, the first FEL beamline in the new hall “Kai Siegbahn” is operational making it possible to run two experiments simultaneously on FLASH1 and FLASH2, both delivering intense, ultra-short laser pulses with user-specific parameters.

    2
    Click me! First user experiment at FLASH2: fluorescence of Xe clusters excited by the FLASH2 pulses. Left: Nozzle where the clusters exit. Middle: fluorescence in the focus of the multilayer mirror (higher intensity left and right of the centre, since there are more clusters which fluoresce). Right (weaker ‘circles’): fluorescence of the clusters in the incoming unfocused FEL beam.

    See the full article here .

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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 12:58 pm on April 4, 2016 Permalink | Reply
    Tags: , , , , , X-ray Technology   

    From SLAC: “Major Upgrade Will Boost Power of World’s Brightest X-ray Laser” 


    SLAC Lab

    April 4, 2016

    Construction begins today on a major upgrade to a unique X-ray laser at the Department of Energy’s SLAC National Accelerator Laboratory. The project will add a second X-ray laser beam that’s 10,000 times brighter, on average, than the first one and fires 8,000 times faster, up to a million pulses per second.

    The project, known as LCLS-II, will greatly increase the power and capacity of SLAC’s Linac Coherent Light Source (LCLS) for experiments that sharpen our view of how nature works on the atomic level and on ultrafast timescales.

    SLAC/LCLS
    SLAC/LCLS

    “LCLS-II will take X-ray science to the next level, opening the door to a whole new range of studies of the ultrafast and ultrasmall,” said LCLS Director Mike Dunne.

    SLAC/LCLS II schematic
    SLAC/LCLS II schematic

    “This will tremendously advance our ability to develop transformative technologies of the future, including novel electronics, life-saving drugs and innovative energy solutions.”

    SLAC Director Chi-Chang Kao said, “Our lab has a long tradition of building and operating premier X-ray sources that help users from around the world pursue cutting-edge research in chemistry, materials science, biology and energy research. LCLS-II will keep the U.S. at the forefront of X-ray science.”


    Access mp4 video here .
    This movie introduces LCLS-II, a future light source at SLAC. It will generate over 8,000 times more light pulses per second than today’s most powerful X-ray laser, LCLS, and produce an almost continuous X-ray beam that on average will be 10,000 times brighter. These unrivaled capabilities will help researchers address a number of grand challenges in science by capturing detailed snapshots of rapid processes that are beyond the reach of other light sources. (SLAC National Accelerator Laboratory)

    A Superior X-ray Microscope

    When LCLS opened six years ago as a DOE Office of Science User Facility, it was the first light source of its kind – a unique X-ray microscope that uses the brightest and fastest X-ray pulses ever made to provide unprecedented details of the atomic world.

    Hundreds of scientists use LCLS each year to catch a glimpse of nature’s fundamental processes in unprecedented detail. Molecular movies reveal how chemical bonds form and break; ultrafast snapshots capture electric charges as they rapidly rearrange in materials and change their properties; and sharp 3-D images of disease-related proteins provide atomic-level details that could hold the key for discovering potential cures.

    The new X-ray laser will work in parallel with the existing one, with each occupying one-third of SLAC’s 2-mile-long linear accelerator tunnel. Together they will allow researchers to make observations over a wider energy range, capture detailed snapshots of rapid processes, probe delicate samples that are beyond the reach of other light sources and gather more data in less time, thus greatly increasing the number of experiments that can be performed at this pioneering facility.

    “The upgrade will benefit X-ray experiments in many different ways, and I’m very excited to use the new capabilities for my own research,” said Brown University Professor Peter Weber, who co-led an LCLS study that used X-ray scattering to track ultrafast structural changes as ring-shaped gas molecules burst open in a chemical reaction vital to many processes in nature. “With LCLS-II, we’ll be able to bring the motions of atoms much more into focus, which will help us better understand the dynamics of crucial chemical reactions.”

    1
    The future LCLS-II X-ray laser (blue, at left) is shown alongside the existing LCLS (red, at right). LCLS uses the last third of SLAC’s 2-mile-long linear accelerator – a hollow copper structure that operates at room temperature and allows the generation of 120 X-ray pulses per second. For LCLS-II, the first third of the copper accelerator will be replaced with a superconducting one, capable of creating up to 1 million X-ray flashes per second. (SLAC National Accelerator Laboratory)

    A Big Leap in X-ray Laser Performance

    3
    This photo shows the prototype of a novel electron source for LCLS-II. Located at the future X-ray laser’s front end, it will produce bunches of electrons for the generation of X-ray pulses that are only quadrillionths of a second long, at rates of up to a million bunches per second. (R. Kaltschmidt/Berkeley Lab)

    Like the existing facility, LCLS-II will use electrons accelerated to nearly the speed of light to generate beams of extremely bright X-ray laser light. The electrons fly through a series of magnets, called an undulator, that forces them to travel a zigzag path and give off energy in the form of X-rays.

    But the way those electrons are accelerated will be quite different, and give LCLS-II much different capabilities.

    At present, electrons are accelerated down a copper pipe that operates at room temperature and allows the generation of 120 X-ray laser pulses per second.

    For LCLS-II, crews will install a superconducting accelerator. It’s called “superconducting” because its niobium metal cavities conduct electricity with nearly zero loss when chilled to minus 456 degrees Fahrenheit. Accelerating electrons through a series of these cavities allows the generation of an almost continuous X-ray laser beam with pulses that are 10,000 times brighter, on average, than those of LCLS and arrive up to a million times per second.

    4
    Electron bunches will gain energy in niobium cavities like these. Cooled to extremely low temperature, these “superconducting” cavities allow radiofrequency fields to boost electron energies without electrical resistance – a crucial property for the acceleration of electrons at a rate of up to a million bunches per second. (R. Hahn/Fermilab)

    In addition to a new accelerator, LCLS-II requires a number of other cutting-edge components, including a new electron source, two powerful cryoplants that produce refrigerant for the niobium structures, and two new undulators to generate X-rays.

    4
    This image shows a segment of an undulator magnet that will turn powerful beams of electrons into extremely bright X-ray light. Two undulators for generating low- and high-energy X-rays at SLAC’s future X-ray laser facility will consist of 21 and 32 segments, respectively. (R. Kaltschmidt/Berkeley Lab)

    6
    Illustration of the electron accelerator of SLAC’s future rapid-fire LCLS-II X-ray laser. No image credit

    Strong Partnerships for a Bright Future in X-ray Science

    6
    For LCLS-II, SLAC has teamed up with four other national labs – Argonne, Berkeley Lab, Fermilab and Jefferson Lab – and Cornell University, with each partner making key contributions to the many aspects of project planning as well as component design, acquisition and construction. (SLAC National Accelerator Laboratory)

    To make this major upgrade a reality, SLAC has teamed up with four other national labs – Argonne, Berkeley Lab, Fermilab and Jefferson Lab – and Cornell University, with each partner making key contributions to project planning as well as to component design, acquisition and construction.

    “We couldn’t do this without our collaborators,” said SLAC’s John Galayda, head of the LCLS-II project team. “To bring all the components together and succeed, we need the expertise of all partners, their key infrastructure and the commitment of their best people.”

    With favorable “Critical Decisions 2 and 3 (CD-2/3)” in March, DOE has formally approved construction of the $1 billion project, which is being funded by DOE’s Office of Science. SLAC is now clearing out the first third of the linac to make room for the superconducting accelerator, which is scheduled to begin operations in the early 2020s. In the meantime, LCLS will continue to serve the X-ray science community, except for a construction-related, six-month downtime in 2017 and a 12-month shutdown extending from 2018 into 2019.

    With the upgrades that are now moving forward, Dunne said, SLAC will have an X-ray laser facility that will enable groundbreaking research for years to come.

    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.
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  • richardmitnick 9:23 pm on March 9, 2016 Permalink | Reply
    Tags: , , , X-ray Technology   

    From SLAC: “5 Ways SLAC’s X-ray Laser Can Change the Way We Live” 


    SLAC Lab

    March 9, 2016

    The First Five Years’ Points to a Bright Future of High-impact Discovery at LCLS

    SLAC LCLS
    LCLS

    SLAC LCLS-II line
    LCLS II

    If you’ve ever stood in a dark room wishing you had a flashlight, then you understand how scientists feel when faced with the mysteries of physical processes that happen at scales that are mind-bogglingly small and fast.

    The future of life-changing science – science that will spawn the electronic devices, medications and energy solutions of the future – depends on being able to see atoms and molecules at work.

    To do that you need special light – such as X-ray light with a wavelength as small as an atom – that pulses at the rate of femtoseconds. A femtosecond is to a second what a second is to 32 million years. It is the timescale for the basic building blocks of chemistry, biology and materials science.

    That’s why, six years ago, the Department of Energy’s SLAC National Accelerator Laboratory answered a bold call by the scientific community: Build a transformative tool for discovery, an X-ray laser so bright and fast it can unravel the hidden dynamics of our physical world.

    Since it began operation in 2009, this singularly powerful “microscope” has generated molecular movies, gotten a glimpse of the birth of a chemical bond, traced electrons moving through materials and made 3-D pictures of proteins that are key to drug discovery. Known to scientists as an X-ray free-electron laser (XFEL), SLAC’s Linac Coherent Light Source, or LCLS, is a DOE Office of Science User Facility that draws many hundreds of scientists from around the world each year to perform innovative experiments.

    The success of LCLS has inspired the spread of such machines all over the world.

    The latest issue of Reviews of Modern Physics contains the most comprehensive scientific overview of its accomplishments in a paper entitled, Linac Coherent Light Source: The First Five Years.

    LCLS staff scientists devoted about a year to compiling the collection of reports, says LCLS Director Mike Dunne.

    “We hope this extensive paper will be a valuable go-to source for this new field of science,” he said. “It describes many of the major accomplishments of the first X-ray laser of its kind. It also testifies to the power of this unique tool for scientific discovery that will benefit society in many ways.”

    Here are five ways SLAC’s X-ray laser and the science it enables can impact our future.

    1. Next-generation Computers and the Power Grid

    LCLS studies are helping to home in on the most promising materials and methods for transforming the electric power grid and driving next-generation computer components beyond classical limits.

    To make computers and other electronics faster and smaller, scientists need to understand and control materials’ magnetism and electronic behavior in new and more precise ways.

    LCLS has given us new, nanoscale views of how laser light rapidly flips the magnetic state of materials, providing new insight on how to write data with light. It has pinpointed the speed of electrical switching – such as what occurs in semiconductor transistors – with trillionth-of-a-second precision.

    Researchers at LCLS have also discovered a new, 3-D phenomenon that may be linked to high-temperature superconductivity, which allows some exotic materials to conduct electricity with zero resistance.

    2. Better, Cleaner Fuels and Chemicals

    The ability to take direct measurements of never-before-seen steps in chemical reactions is what scientists need to design more efficient reactions to produce fuels, fertilizers and industrial chemicals.

    While we know the starting ingredients and outcomes of chemical reactions, the early and middle steps are hard to see in real time at the atomic scale.

    LCLS X-ray pulses are so fast that they allow us to observe and analyze these previously unseen steps. They work like ultrabright flashes to capture X-ray snapshots of chemical reactions as they happen.

    Researchers have used LCLS to see new details of a reaction in catalytic converters that neutralizes pollution from car exhaust, and to produce “molecular movies” of a molecule transforming after one of its chemical bonds breaks.

    3. More Effective Medication with Fewer Side Effects

    Half of the medications on the market target special receptor proteins in the outer layer of our cells. To figure out how drugs work so we can make them more effective and reduce side effects, we need to see how they dock with these receptors in atom-by-atom detail.

    The best way to see how they fit is to form the protein-drug complexes into crystals and study them with X-rays, but many important samples don’t form big enough crystals or are too damage-prone for conventional X-ray tools. LCLS, though, can study very tiny crystals under more natural conditions, making it possible to determine the 3-D atomic structure of important proteins that had been out of reach.

    Already, LCLS has revealed a potential weakness in a protein involved in the transmission of African sleeping sickness, provided the best 3-D atomic-scale look at how blood pressure medicines and painkillers interact with receptors in our cells, and pinpointed the mechanism that allows our brain to send ultrafast chemical signals.

    In more recent studies, LCLS has also been used to image living bacteria that are responsible for generating the oxygen in our atmosphere, demonstrating an entirely new X-ray imaging technique.

    4. Renewable Energy that Mimics Nature

    LCLS allows us to study how plants use energy from sunlight to release oxygen into the air we breathe during a process called photosynthesis. The X-ray laser is uniquely capable of mapping the individual sunlight-triggered steps. Early data is already giving us a detailed understanding of photosynthesis – information that’s crucial for developing renewable, clean sources of energy that mimic nature.

    Scientists are also using the tool to study how light affects other living things. Just as sunlight can be life-giving, it can also be damaging. Studies at LCLS have revealed how our DNA protects itself from the sun’s ultraviolet rays and how proteins in bacteria and in our eyes shift shape in response to light.

    5. Fusion Reactions and Seeing Inside Planets

    High-power laser systems at SLAC heat matter to millions of degrees and crush it with billions of tons of pressure per square inch. Scientists use LCLS to measure what happens to matter under these extreme conditions with high precision at very small scales, and over very short periods of time.

    Some studies test the resilience of materials, such as those used in jet engines, to see how they fail. Others have simulated and studied the shock effects of meteorite impacts and have reproduced the conditions that are believed to exist at the heart of giant gas planets, which improves our understanding of how solar systems form.

    The results also give scientists new insight into how to replicate the fusion reactions that fuel our sun, an essential step in the pursuit of fusion energy as a power source.
    Looking to the Future

    “Many of the methods developed over the first years of LCLS operations responded to the needs of science to address vital areas of discovery that promise to have a significant impact on our lives,” Dunne emphasizes. “We expect that the coming years of XFEL innovation will push us further into the future, as we look ever deeper into the dynamics of our natural world.”

    “The Linac Coherent Light Source: The First Five Years,” was authored by a team representative of the X-ray and accelerator science groups at SLAC during this pioneering period of XFEL science: Christoph Bostedt, Sébastien Boutet, David M. Fritz, Zhirong Huang, Hae Ja Lee, Henrik T. Lemke, Aymeric Robert, William F. Schlotter, Joshua J. Turner and Garth J. Williams.

    Citation: Bostedt, et al., Reviews of Modern Physics, 9 March 2016 (10.1103/RevModPhys.88.015007).

    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.
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