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News Article | April 18, 2017
Site: www.rdmag.com

SLAC National Accelerator Laboratory has a love of the femtosecond. In fact, they are dedicating an entire week to the femtosecond—one quadrillionth of a second—from April 17 to April 21. Each day SLAC scientists explain how science can be used to examine things on the femtosecond scale, which helps better explain virtually every reaction in nature. On Monday, April 17, Ryan Coffee, a physicist at SLAC, explained in an online video posted to the SLAC website the importance of being able to break things down at the femtosecond level. “The first steps in the chemical reactions that happen in your blood with oxygen moving around, or photoabsorption in light harvesting in the plants in your garden or even the formation of plaques in your blood that give you diabetes or degenerative diseases happen on the femtosecond time scale,” Coffee said. As part of Femtosecond Week, Phil Bucksbaum, director of the Pulse Institute at SLAC and Stanford University explained  that until recently the tiny, rapid motion of every molecule, atom and electron needed to obey the laws of quantum physics was hidden from view because it is too small and too fast to record in real time. However, new tools including the bright X-ray pulses at the Linac Coherent Light Source and the advanced ultrashort pulse lasers and electron beams at SLAC, can capture snapshot images that last only femtoseconds. Coffee also said recent advancements led to a better understanding of molecular nature. “The field of ultra-fast science has been used in chemistry for probably 10, 20 years now and it has delivered much of the fundamental understanding of how light interacts with molecules,” Coffee said. “The idea is now we can make these molecular movies because we have now X-rays that can probe the molecules at exactly that natural timeframe of the reactions. “Now that we have x-rays to see at the scale of molecules and we have the timeframe with femtoseconds that are on the scale of how fast these molecules move, how they change their shape, we can start to look at why nature made the molecules the shapes that she did,” he added. According to Bucksbaum, this is a flash of light short enough to freeze the motion of atoms in molecules. Faster probes under development by scientists at SLAC will soon be able to track the motion of electrons as they cross single chemical bonds in less than a single femtosecond. Scientists can piece these snapshots together to make slow-motion molecular movies that show how nature works and these femtosecond movies can also help scientists develop novel materials and new chemicals and help better explain how all processes in nature depend on femtosecond motion on the atomic scale. Also included in Femtosecond Week is a Q&A with Agostino Marinelli, who is involved in research and developed related to the femtosecond at LCLS. “It’s the fastest we can reach now with X-rays, and as an accelerator physicist, I get excited about technical things like that,” Marinelli said in the Q&A posted on the SLAC website on April 17. Marinelli explained how the femtosecond is broken down. “Normally LCLS shoots 120 X-ray pulses a second. But you can also make it send two pulses of different energies, separated by a few to 100 femtoseconds,” he said. “You excite your sample with the first one and probe it with the second. You have to observe it within femtoseconds after you excite it because reactions happen that fast. According to Marinelli, there are several things being studied on the femtosecond scale including chemical reactions where you can see the positions of the atoms rearranging as it happens. However, Marinelli said the next progression might be to go beyond the femtosecond scale. “I’m really excited about what I’m about to do, which is this sub-femtosecond project called XLEAP,” he said. “We will shape the LCLS electron beam with a high-power infrared laser and use it to generate pulses that are shorter than a femtosecond! What we will be looking at is energy and electrons moving around a molecule, which happens even faster than the atoms rearranging. “Right now we’re really blind to all of this. To me, the way I understand it is, going to that timescale, you’re peeking into the very fundamental, quantum nature of the electrons in the molecule.” In another Q&A posted by SLAC on Tuesday, April 18, Gabriella Carini, Ph.D., of LCLS, explained some of the challenges in working on the femtosecond scale. “In more traditional X-ray sources the photons arrive distributed over time, one after the other, but when you work with ultrafast laser pulses like the ones from LCLS, all your information about a sample arrives in a few femtoseconds,” she said. “Your detector has to digest this entire signal at once, process the information and send it out before another pulse comes. “This requires deep understanding of the detector physics and needs careful engineering. You need to optimize the whole signal chain from the sensor to the readout electronics to the data transmission.” Each day during the week another interview with a SLAC scientist on the miniscule time measurement will be posted online. Some of the topics will include how the femtosecond relates to biology, chemistry, high energy density science and materials. Other activities include a virtual tour of the undulators and near experimental hall at LCLS, which will be posted April 19 and a Twitter chat with the hashtag #femtoweek with Mike Dunne, director of LCLS held on April 18, along with other factsheets and interviews that will be posted throughout the week. For more information about Femtosecond Week: https://home.slac.stanford.edu/femtosecond-week/


The method of taking these pictures is a collaborative creation that involved Kansas State University researchers Artem Rudenko and Daniel Rolles, both assistant professors of physics. The movies help scientists understand interactions of intense laser light with matter. But even more importantly, these experiments lead the way to filming various processes that involve ultrafast dynamics of microscopic samples, such as the formation of aerosols—which play a major role in climate models—or laser-driven fusion. "We can create a real movie of the microworld," Rudenko said. "The key development is that now we can take sequences of pictures on the nanoscale." Rudenko and Rolles—both affiliated with the university's James R. Macdonald Laboratory—collaborated with researchers at SLAC National Accelerator Laboratory at Stanford University, Argonne National Laboratory and the Max Planck Institutes in Germany. Their publication, "Femtosecond and nanometre visualization of structural dynamics in superheated nanoparticles," appears in Nature Photonics. In this work, the collaboration used intense lasers to heat xenon nanoscale clusters and then took a series of X-ray pictures to show what happened to the particles. The picture series became a movie of how these objects move at the level of femtoseconds, which are one-millionth of a billionth of a second. "What makes nano so interesting is that the behavior for many things changes when you get to the nanoscale," Rolles said. "Nano-objects bridge the gap between bulk matter and individual atoms or molecules. This research helps us as we try to understand the behavior of nano-objects and how they change shape and properties within extremely short times." The pictures of the nanoparticles cannot be taken with normal optical light, but must be taken with X-rays because X-ray light has nanometer wavelengths that enable researchers to view nanoscale objects, Rolles said. The light wavelength must match the size of the object. To take the pictures, the researchers needed two ingredients: very short X-ray pulses and very powerful X-ray pulses. The Linac Coherent Light Source at SLAC provided those two ingredients, and Rudenko and Rolles traveled to California to use this machine to take the perfect pictures. The photo-taking method and the pictures it produces have numerous applications in physics and chemistry, Rolles said. The method is also valuable for visualizing laser interactions with nanoparticles and for the rapidly developing field of nanoplasmonics, in which the properties of nanoparticles are manipulated with intense light fields. This may help to build next-generation electronics. "Light-driven electronics can be much faster than conventional electronics because the key processes will be driven by light, which can be extremely fast," Rudenko said. "This research has big potential for optoelectronics, but in order to improve technology, we need to know how a laser drives those nanoparticles. The movie-making technology is an important step in this direction." Rudenko and Rolles are continuing to improve the moviemaking process. In collaboration with the university's soft matter physics group, they have extended the range of samples, which can be put into the X-ray machine and now can produce movies of gold and silica nanoparticles. Explore further: Dual camera smartphones – the missing link that will bring augmented reality into the mainstream More information: Tais Gorkhover et al. Femtosecond and nanometre visualization of structural dynamics in superheated nanoparticles, Nature Photonics (2016). DOI: 10.1038/nphoton.2015.264


News Article | April 6, 2016
Site: www.nanotech-now.com

Abstract: Think of it as a microscopic movie: A sequence of X-ray images shows the explosion of superheated nanoparticles. The picture series reveals how the atoms in these particles move, how they form plasma and how the particles change shape. The method of taking these pictures is a collaborative creation that involved Kansas State University researchers Artem Rudenko and Daniel Rolles, both assistant professors of physics. The movies help scientists understand interactions of intense laser light with matter. But even more importantly, these experiments lead the way to filming various processes that involve ultrafast dynamics of microscopic samples, such as the formation of aerosols -- which play a major role in climate models -- or laser-driven fusion. "We can create a real movie of the microworld," Rudenko said. "The key development is that now we can take sequences of pictures on the nanoscale." Rudenko and Rolles -- both affiliated with the university's James R. Macdonald Laboratory -- collaborated with researchers at SLAC National Accelerator Laboratory at Stanford University, Argonne National Laboratory and the Max Planck Institutes in Germany. Their publication, "Femtosecond and nanometre visualization of structural dynamics in superheated nanoparticles," appears in Nature Photonics. In this work, the collaboration used intense lasers to heat xenon nanoscale clusters and then took a series of X-ray pictures to show what happened to the particles. The picture series became a movie of how these objects move at the level of femtoseconds, which are one-millionth of a billionth of a second. "What makes nano so interesting is that the behavior for many things changes when you get to the nanoscale," Rolles said. "Nano-objects bridge the gap between bulk matter and individual atoms or molecules. This research helps us as we try to understand the behavior of nano-objects and how they change shape and properties within extremely short times." The pictures of the nanoparticles cannot be taken with normal optical light, but must be taken with X-rays because X-ray light has nanometer wavelengths that enable researchers to view nanoscale objects, Rolles said. The light wavelength must match the size of the object. To take the pictures, the researchers needed two ingredients: very short X-ray pulses and very powerful X-ray pulses. The Linac Coherent Light Source at SLAC provided those two ingredients, and Rudenko and Rolles traveled to California to use this machine to take the perfect pictures. The photo-taking method and the pictures it produces have numerous applications in physics and chemistry, Rolles said. The method is also valuable for visualizing laser interactions with nanoparticles and for the rapidly developing field of nanoplasmonics, in which the properties of nanoparticles are manipulated with intense light fields. This may help to build next-generation electronics. "Light-driven electronics can be much faster than conventional electronics because the key processes will be driven by light, which can be extremely fast," Rudenko said. "This research has big potential for optoelectronics, but in order to improve technology, we need to know how a laser drives those nanoparticles. The movie-making technology is an important step in this direction." Rudenko and Rolles are continuing to improve the moviemaking process. In collaboration with the university's soft matter physics group, they have extended the range of samples, which can be put into the X-ray machine and now can produce movies of gold and silica nanoparticles. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.


News Article | February 28, 2017
Site: phys.org

Acoustic droplet ejection allows scientists to deposit nanoliters of sample directly into the X-ray beam, considerably increasing the efficiency of sample consumption. A femtosecond pulse from an X-ray free-electron laser then intersects with a droplet that contains protein crystals. Credit: SLAC National Accelerator Laboratory Biological samples studied with intense X-rays at free-electron lasers are destroyed within nanoseconds after they are exposed. Because of this, the samples need to be continually refreshed to allow the many images needed for an experiment to be obtained. Conventional methods use jets that supply a continuous stream of samples, but this can be very wasteful as the X-rays only interact with a tiny fraction of the injected material. To help address this issue, scientists at the Department of Energy's Lawrence Berkeley National Laboratory, SLAC National Accelerator Laboratory, Brookhaven National Laboratory, and other institutes designed a new assembly-line system that rapidly replaces exposed samples by moving droplets along a miniature conveyor belt, timed to coincide with the arrival of the X-ray pulses. The droplet-on-tape system now allows the team to study the biochemical reactions in real-time from microseconds to seconds, revealing the stages of these complex reactions. In their approach, protein solution or crystals are precisely deposited in tiny liquid drops, made as ultrasound waves push the liquid onto a moving tape. As the drops move forward, they are hit with pulses of visible light or treated with oxygen gas, which triggers different chemical reactions depending on the sample studied. This allows the study of processes such as photosynthesis, which determines how plants absorb light from the sun and convert it into useable energy. Finally, powerful X-ray pulses from SLAC's X-ray laser, the Linac Coherent Light Source (LCLS), probe the drops. In this study published in Nature Methods, the X-ray light scattered from the sample onto two different detectors simultaneously, one for X-ray crystallography and the other for X-ray emission spectroscopy. These are two complementary methods that provide information about the geometric and electronic structure of the catalytic sites of the proteins and allowed them to watch with atomic precision how the protein structures changed during the reaction. Explore further: New, detailed snapshots capture photosynthesis at room temperature More information: Drop-on-demand sample delivery for studying biocatalysts in action at X-ray free-electron lasers. Nature Methods (2017) DOI: 10.1038/nmeth.4195


News Article | December 5, 2016
Site: www.rdmag.com

A mystery that has perplexed scientists for centuries may soon be unraveling. Researchers at the Department of Energy’s SLAC National Accelerator Laboratory have captured for the first time how a protein complex—photosystem II—harvests energy from sunlight and uses it to split water into hydrogen and oxygen, a process that generates the oxygen in the atmosphere. Using new X-ray methods, scientists were able to capture the highest-resolution room-temperature images of the protein complex, which allows scientists to closely watch how water is split during photosynthesis at the temperature at which it occurs naturally. The team of scientists used the bright, fast pulses of X-rays at SLAC’s X-ray free-electron laser—the Linac Coherent Light Source (LCLS), a DOE Office of Science User Facility. Uwe Bergmann, Ph.D., a distinguished scientist at SLAC and co-author of the paper that first appeared in Nature, said in an interview with R&D Magazine by viewing photosynthesis in its natural occurrence scientists can finally learn about the process that has been around since the beginning of time. “It is believed that this process of how this is done has never changed since the beginning,” Bergmann said. “I believe we are at the final step, I believe we have all the tools together of finally cracking this 3-billion-year old puzzle, mainly what exactly goes on in photosynthesis.” By understanding photosynthesis further, scientists may be able to develop ways to create artificial photosynthesis devices that can serve as potential clean energy sources. Bergmann said the advancements in lab equipment has led to the breakthrough viewing photosynthesis. “We simulate the sun with a short laser flash in the laboratory to synchronize the process,” he said. “You need to have a really well defined power of your optical laser, which simulates the sunlight, you need to have a well-defined time difference between the flashes. “We believe that we have the system which can do it pretty much in place now.” Until recently, scientists were only able to view the resting state of photosynthesis in detail using samples that were frozen. However, by using higher resolution imaging they were able to see two crucial steps in photosynthetic water splitting under normal conditions, which will lead to further research on how the process works in detail. Samples experienced radiation damage from previous high-resolution studies of the system at synchrotron light sources from the longer exposure to X-rays. However, the researchers at LCLS were able to take advantage of the ultrafast laser pulses to collect X-ray crystallography and spectroscopy data before damage occurred. During another recent experiment at SACLA, the only other operating hard X-ray free-electron laser, scientists were able to look at the first step in the cycle in a frozen sample and under dark conditions—which means the water-splitting reaction had not yet been initiated in the protein complex. The scientists were able to place droplets of the sample in a solution with small, crystallized forms of the photosystem II on a moving conveyor belt and illuminated the samples with pulses of green light from a laser to initiate the water-splitting reaction. After two light pulses, the images of the crystals were captured using X-rays with a resolution finer than 2.5 angstroms—significantly better than previously achieved at room temperature. The water-splitting reaction takes place at a metal catalyst within the photosystem II protein, known as the oxygen-evolving complex, which is made up of four manganese atoms and one calcium atom. The protein complex uses the energy from light to form pure oxygen from two water molecules, where the four manganese atoms are critical in shuffling electrons through the cycle. However, it is unknown where exactly in the complex the involved water is located or where the oxygen formation occurs. The researchers were able to sort this out by using ammonia—a water substitute—to narrow down where oxygen atoms from two water molecules combine to form an oxygen molecule. If the ammonia was bound to a site and the reaction still proceeded, then that site is unlikely to be part of the oxygen molecule formation. The result of this experiment conflicted with two leading theories for how the reaction proceeds within the oxygen-evolving complex. The same technique will now be used in future studies where researchers hope to capture more images at different steps of the process, which will allow them to further refine the details of the water-splitting reaction. Bergmann described photosynthesis as one of the oldest mysteries of the planet because more than 3 billion years ago the atmosphere of the Earth was mainly carbon dioxide and methane and there was no oxygen in the atmosphere. According to Bergmann, life had evolved over time in the form of very simple bacteria, some of which began to use the electrons, which you can get by splitting two water molecules. At the time, the oxygen byproduct from the water molecules was toxic because no life on Earth was prepared for that byproduct. “That really changed the history of the planet and that happened about 3.2 billion years ago,” Bergmann said. Bergmann said around 550 million years the atmosphere was about 10 percent oxygen and today’s atmosphere is estimated to be between 18 and 20 percent oxygen. Bergmann said he expects some big scientific advancements regarding photosynthesis. “It is a race and we are approaching the finishing line of a marathon,” he said. “Everyone has a different strategy how to go about this and at the end of the day you do need to do this work at room temperature in real time at the conditions that the real leaf of a tree or bacteria in the ocean performs this reaction. “This is a game changer and to do it with atomic resolution has been impossible in the past.” The international research team is a long-standing collaboration between SLAC and Berkeley Lab and includes Humboldt University in Germany, Umeå University and Uppsala University in Sweden, Stanford University, Brookhaven National Laboratory and University of Oxford in the United Kingdom. The study, which appeared in Nature on Nov. 21, can be viewed here.


The results, published today in Nature, show the game-changing potential of X-ray free-electron lasers, or XFELs, for studying RNA, which guides protein manufacturing in the cell, serves as the primary genetic material in retroviruses such as HIV and also plays a role in most forms of cancer. And because this particular type of RNA switch, known as a riboswitch, is found only in bacteria, a deeper understanding of its function may offer a way to turn off protein production and kill harmful germs without causing side effects in the humans they infect. "Previous experiments at SLAC's X-ray laser have studied biological reactions like photosynthesis that are triggered by light. But this is the first to observe one that is triggered by the chemical interaction of two biomolecules in real time and at the atomic scale," said Yun-Xing Wang, a structural biologist at the National Cancer Institute's Center for Cancer Research who led the international research team. "This really demonstrates the unique capability that X-ray free-electron lasers offer that no current technology, or any other technology on the horizon, can do. It's like you have a camera with a very fast shutter speed, so you can catch every move of the biomolecules in action." The experiments were carried out at SLAC's Linac Coherent Light Source (LCLS), a DOE Office of Science User Facility. They are the first to demonstrate how XFELs can take snapshots and potentially make movies of RNA and other biomolecules as they chemically interact - offering glimpses into fundamental workings of the cell that can't be obtained any other way. RNA is a key part of the genetic material in all living cells. It comes in several types that work together to guide the production of proteins by the cell's ribosomes, according to blueprints encoded in DNA. But both DNA and RNA also contain extensive regions that don't code for any protein - the so-called genetic "dark matter." Scientists thought for many years that these regions didn't do anything. Now they know that they play an important role in determining where and when genes turn on and off and otherwise fine-tuning their function. The vast majority of cancers are due to mutations in these non-coding regions, Wang said, so understanding how these regions work is important for cancer research as well as fundamental biology. However, figuring out what the RNA non-coding regions do is difficult. RNA molecules are wobbly and flexible, so it's hard to incorporate them into the large crystals typically needed to study their atomic structure at X-ray light sources. LCLS removes this barrier by allowing scientists to get structural information from much smaller, nanosized crystals, which are much easier to make. Its powerful X-ray laser pulses, a billion times brighter than any available before, are so short that they collect data from each crystal in a few millionths of a billionth of a second, before damage from the X-rays sets in. Wang's team studied a riboswitch from Vibrio vulnificus, a bacterium related to the one that causes cholera. The riboswitch sits in a long strand of messenger RNA (mRNA), which copies DNA's instructions for making a protein so they can be read and carried out by the ribosome. The switch acts like a thermostat that regulates protein production. In this case, the mRNA guides production of a protein that in turn helps to produce a small molecule called adenine. When there is too much adenine in the bacterial cell, adenine molecules enter pockets in the riboswitches and flip the riboswitches into a different shape, and this changes the pace of protein and adenine production. First Stills of an Elegant Film For the LCLS experiments, the researchers made nanocrystals that incorporated millions of copies of the riboswitch and mixed them with a solution containing adenine molecules. Each crystal was so small that adenine could quickly and uniformly penetrate into every corner of it, enter riboswitch pockets and flip them almost instantaneously, as if they were millions of synchronized swimmers executing a single flawless move. The scientists took snapshots of this interaction by hitting the crystals with X-ray laser pulses at carefully timed intervals after the mixing started. This gave them the first glimpse of a fleeting intermediate stage in the process, which occurred 10 seconds in. Separately, they obtained the first images of the riboswitch in its initial, empty-pocket state, and discovered that it existed in two slightly different configurations, only one of which participates in switching. The researchers were surprised to discover that the sudden change in the shape of the riboswitches was so dramatic that it changed the shape of the entire crystal, too. Normally a major change like this would crack the crystal and spoil the experiment. But because these crystals were so small they held together, so the X-ray laser could still get structural information from them. "To me it's still a mystery how the crystal managed to do that," said Soichi Wakatsuki, a professor at SLAC and at the Stanford School of Medicine and head of the lab's Biosciences Division, who was not part of the research team. "This actually opens up a lot of new possibilities and gives us a new way to look at how RNA and proteins interact with small molecules, so this is very exciting." Explore further: Scientists watch bacterial sensor respond to light in real time More information: J. R. Stagno et al, Structures of riboswitch RNA reaction states by mix-and-inject XFEL serial crystallography, Nature (2016). DOI: 10.1038/nature20599


In one experiment, a team led by Lindenberg showed atoms shifting in trillionths of a second to produce a wrinkle in a 3-atom-thick sample of a material that might someday be used in flexible electronics. Another study observed semiconductor crystals—called "quantum dots" because they defy classical physics at the nanoscale—expand and shrink in response to ultrafast pulses of laser light. Revealing such intriguing properties at the nanoscale gives clues about the fundamental nature of materials and how they perform in applications we rely on for energy or information. "Even though some of these materials are completely embedded in everyday technologies, not a lot is understood about how they work," says Lindenberg, who is an associate professor of materials science and engineering and of photon science. He is also a principal investigator for two SLAC/Stanford joint institutes—Stanford Institute for Materials and Energy Sciences and Stanford PULSE Institute. "Part of the reason some phenomena are not well understood is because they happen so fast – in billionths, trillionths or even quadrillionths of a second. For the first time, we have tools that allow us to see these things," he says. Working at the intersection of materials science and engineering, Lindenberg and his team have a particular focus on finding promising materials for next-generation electronics, light-based data storage technologies and energy applications. "There are a broad range of new properties that emerge at the nanoscale," Lindenberg says. "The tiniest samples, with just tens or hundreds of atoms, can have nearly flawless structures that make them ideal test tubes for very fundamental questions about what happens when a material transforms." The team uses different types of laser light at SLAC and Stanford labs to learn how simple tweaks in the size, shape and design of materials can change their basic properties in unexpected ways, which could lead to new applications. Taking advantage of the powerful X-rays at SLAC facilities, including the Linac Coherent Light Source and the Stanford Synchrotron Radiation Lightsource, they explore ultrafast changes in nanoscale samples. "We are trying to understand how electrons or atoms move in materials, which in turn determines, for example, the efficiency of solar cells and other energy-related materials, and how materials switch between different forms," he says. "Ultrafast techniques allow you to see these kinds of things in a completely new way." Explore further: Scientists use LCLS to see photovoltaic process in action


News Article | September 12, 2016
Site: www.sciencedaily.com

To understand how molecules undergo light-driven chemical transformations, scientists need to be able to follow the atoms and electrons within the energized molecule as it gains and loses energy. In a recent study, scientists used the ultrafast high-intensity pulsed X-rays produced by the Linac Coherent Light Source to take molecular snapshots of these molecules.


News Article | April 5, 2016
Site: www.rdmag.com

Construction has begun 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. “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. “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.” 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 two-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.” 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. 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. 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. SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, CA, SLAC is operated by Stanford University for the U.S. Department of Energy Office of Science.. SLAC National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time.


News Article | April 4, 2016
Site: phys.org

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. "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. "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." 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." 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. 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. 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. Explore further: First X-ray laser's early success brings approval for next-phase facility

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