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  • richardmitnick 9:09 pm on September 21, 2017 Permalink | Reply
    Tags: , Diamond Light Source, , Rift Valley fever phlebovirus (RVFV), Significant step made towards understanding Rift Valley Fever virus, , X-ray Technology   

    From University of St Andrews: “Significant step made towards understanding Rift Valley Fever virus” 

    U St Andrews bloc

    University of St Andrews

    21 September 2017
    Fiona MacLeod
    01334 462108/07714 140 559
    fm43@st-andrews.ac.uk

    1
    The NSs protein of RVFV forms characteristic filaments (green) in the nuclei of infected cells (red): a three-dimensional structure of a fibrillar assembly of NSs, determined by Barski et al using X-ray crystallography (green) is shown on top of an image of three infected cells. Image credit: Ben Brennan and Uli Schwarz-Linek.

    Researchers at the Universities of St Andrews and Glasgow have made a significant step forward in tackling a viral disease which causes frequent epidemics in Africa and could spread to Europe due to global warming.

    Dr Michal Barski and Dr Uli Schwarz-Linek of the School of Biology at the University of St Andrews, with colleagues at the University of Glasgow, have published a paper in online journal eLife revealing new information about a key molecule used by the virus to cause disease, which could help to eventually find a cure or a vaccine.

    Rift Valley fever phlebovirus (RVFV) is a virus affecting humans and livestock which is transmitted by mosquitos and contact with infected animals. RVFV is increasingly likely to cause widespread epidemics, and could potentially follow the pattern of Dengue virus or West Nile virus and spread to temperate regions, such as Europe or the USA, as global warming allows the mosquitos which carry the virus to extend their geographic range.

    Infection can cause severe disease, including haemorrhagic fever, and may lead to death. Historically, the virus was only found in central Africa but has spread to the Arabian Peninsula. There are no vaccines or treatments available for use in humans so if there is a serious outbreak of the virus it could become an epidemic and cause great economic loss and severe human disease.

    The research team combined two techniques, NMR spectroscopy and X-ray crystallography, carried out at Diamond Light Source, to study the atomic three-dimensional structure of NSs – a key molecule of the RVFV virus which assembles into large fibres inside infected cells.

    Diamond Light Source, located at the Harwell Science and Innovation Campus in Oxfordshire U.K.

    The virus relies on NSs to cause disease but the mechanism behind this process, and the formation of the fibres, have not been fully understood. The structure of this molecule revealed that only the central part, or core domain, of the protein is needed for the fibres to form. Further experiments identified how NSs molecules come together to build the fibres inside the infected cells.

    Dr Schwarz-Linek said: “The structural insights we generated will help to unravel the complexity of Rift Valley fever. It will pave the way for research on Rift Valley fever phlebovirus and many other related viruses that have the ability to infect animals and humans.”

    Dr Barski added: “With this research we have opened up a new avenue for understanding Rift Valley fever virus and hopefully also for developing therapy targeted at this virus. The recent, sudden epidemics of Ebola virus and Zika virus have highlighted the need to understand dangerous tropical viral diseases which could quickly spread to far away places. Rift Valley fever is on that very short list of viruses which might cause large epidemics next.”

    These findings mark an important step towards understanding how the NSs protein helps RVFV to cause disease in humans and livestock. In the future, this work may aid the development of much needed drugs and vaccines against RVFV.

    Earlier this year the World Health Organization ranked RVFV among the ten most dangerous pathogens most likely to cause wide epidemics in the near future, requiring urgent attention.

    See the full article here .

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    U St Andrews campus

    St Andrews is made up from a variety of institutions, including three constituent colleges (United College, St Mary’s College, and St Leonard’s College) and 18 academic schools organised into four faculties. The university occupies historic and modern buildings located throughout the town. The academic year is divided into two terms, Martinmas and Candlemas. In term time, over one-third of the town’s population is either a staff member or student of the university. The student body is notably diverse: over 120 nationalities are represented with over 45% of its intake from countries outside the UK; about one-eighth of the students are from the rest of the EU and the remaining third are from overseas — 15% from North America alone. The university’s sport teams compete in BUCS competitions, and the student body is known for preserving ancient traditions such as Raisin Weekend, May Dip, and the wearing of distinctive academic dress.

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  • richardmitnick 10:24 pm on September 20, 2017 Permalink | Reply
    Tags: , , , , X-ray Technology   

    From SLAC: “High-Speed Movie Aids Scientists Who Design Glowing Molecules” 


    SLAC Lab

    September 20, 2017
    Amanda Solliday

    1
    Aequorea victoria, also called the crystal jelly, is a bioluminescent jellyfish that lives near the Pacific coast of North America. (Gary Kavanagh/iStockphoto.com)

    2
    The Coherent X-Ray Imaging (CXI) instrument makes use of the brilliant hard X-ray pulses from the Linac Coherent Light Source. The equipment is tailored for X-ray crystallography experiments. (SLAC National Accelerator Laboratory)

    SLAC/LCLS

    With SLAC’s X-ray laser, a research team captured ultrafast changes in fluorescent proteins between “dark” and “light” states. The insights allowed the scientists to design improved markers for biological imaging.

    The crystal jellyfish swims off the coast of the Pacific Northwest and can illuminate the waters when disturbed. That glow comes from proteins that absorb energy and then release it as bright flashes.

    To track many of life’s activities, biologists took a cue from this same jellyfish.

    Scientists collected one of the proteins found in the sea creatures, green fluorescent protein (GFP), and engineered a molecular light switch that would glow or remain dark depending on specific experimental conditions. The glowing labels are attached to molecules in living cells so researchers can highlight them during imaging experiments. They use these fluorescent markers to understand how a cell responds to changes in its environment, identify which molecules interact within a cell and track the effects of genetic mutations.

    Researchers have studied GFP and other fluorescent proteins for decades to better understand their glowing action and improve their function in scientific studies, but they have never been able to observe the ultrafast changes that occur between “off” and “on” states until now.

    In a recent experiment conducted at the Department of Energy’s SLAC National Accelerator Laboratory, a research team used bright, ultrafast X-ray pulses from SLAC’s X-ray free-electron laser to create a high-speed movie of a fluorescent protein in action. With that information, the scientists began to design a marker that switches more easily, a quality that can improve resolution during biological imaging.

    “We think that this approach will open a world of possibilities to tailor fluorescent proteins,” says Martin Weik, scientist at the Institute of Structural Biology in Grenoble, France and one of the authors on the publication. “We not only have the structure of the fluorescent protein, but now we can see what is happening between one static state and the other.”

    Nature Chemistry published the study on Sept. 11.

    Filming a Molecular Light Switch

    To observe these intermediate states, the scientists initiated a photochemical reaction in the fluorescent protein with an optical laser at the Coherent X-ray Imaging instrument at the Linac Coherent Light Source, followed by X-ray snapshots at distinct time delays. The optical laser provides energy in the form of photons, mimicking what happens in nature.

    “Atoms move around in the photoactive site of the molecule as a result of absorption of a photon,” says Sebastien Boutet, SLAC scientist and a co-author of the paper. “This structural change turns the protein from a dark state to a light-emitting (fluorescent) state.”

    There’s a vast body of literature calculating what might happen between the two states, but no one studying the protein was able to see the structural changes in the switch as the photon is absorbed. The molecular switch was just too fast for traditional X-ray imaging techniques.

    In this study, the femtosecond X-ray pulses generated by LCLS—arriving in just millionths of a billionth of a second—allowed the team to create stop-action images of the process at an extremely close interval after the proteins were activated by the optical laser.

    A Door Half Open

    The high-speed snapshots were used to generate a movie starting from the dark state, and gave the researchers insights that they used to design more efficient switchable light-emitting proteins. They found a clue in the time the molecules spent between fluorescent and non-fluorescent states.

    “After a picosecond, and for a very short time, this molecular switch is stuck between on and off,” says Ilme Schlichting, scientist at the Max-Planck Institute in Heidelberg, Germany and one of the authors on the publication. “People have predicted this, but to actually visualize its structure is extremely exciting.”

    “It’s as if there’s a door and it’s neither closed nor completely open; it’s half open,” she says. “And now we are learning what can go through the door, what might be blocking it and how it works in real time.”

    In this study, the scientists found that an amino acid blocked the door and prevented the switch from flipping as easily as possible.

    The researchers shortened the amino acid in a mutated version of the fluorescent protein. This engineered version switched more easily and gave better contrast. These traits will allow scientists to observe cellular activity with greater precision.

    “Contrast is essential in imaging. It’s like on a TV screen, where to see the best picture, you want the dark to be extremely dark and the color to be super bright and colorful,” says Jacques-Philippe Colletier, a scientist at the Institute of Structural Biology who contributed to the research.

    This new molecular movie featuring the jellyfish-inspired proteins lights the way to capture more of life’s microscopic details. The team will continue to fine-tune the protein for other desired characteristics that make it ideal for “super-resolution microscopy,” a type of light microscopy where scientists are able to see illuminated details of cells not distinguishable with conventional light microscopy methods.

    The research collaboration included several French institutions, including the Institute of Structural Biology, University of Lille, University of Paris-Sud and the University of Rennes, as well as Max Planck Institutes in Germany and SLAC.

    LCLS is a DOE Office of Science User Facility.

    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.
    i1

     
  • richardmitnick 8:57 am on September 20, 2017 Permalink | Reply
    Tags: , , , , , First user groups, , X-ray Technology   

    From XFEL: “First users at European XFEL” 

    XFEL bloc

    European XFEL

    2017/09/20
    No writer credit

    1
    DESY’s Anton Barty (left) and Henry Chapman (right), seen at the SPB/SFX instrument, were in one of the first two user groups. (Photo: DESY, Lars Berg)

    The first users have now started experiments at the new international research facility in Schenefeld.

    “This is a very important event, and we are very happy that the first users have now arrived at European XFEL so we can do a full scale test of the facility” said European XFEL Managing Director Prof. Dr. Robert Feidenhans’l. ”The instruments and the supporting teams have made great progress in the recent weeks and months. Together with our first users, we will now do the first real commissioning experiments and collect valuable scientific data. At the same time, we will continue to further advance our facility and concentrate on further improving the integration and stability of the instrumentation” he added.

    The first two instruments available for users in the underground experiment hall are the FXE (Femtosecond X-Ray Experiments) instrument, and the SPB/SFX (Single Particles, Clusters, and Biomolecules and Serial Femtosecond Crystallography) instrument.

    The FXE instrument will enable the research of extremely fast processes. It will be possible to create “molecular movies” showing the progression of chemical reactions which, for example, will help improve our understanding of how catalysts work, or how plants convert light into usable chemical energy. The first seven experiments conducted at FXE highlight the range of methods available at the instrument and the diversity of topics of study possible. Experiments will include using different spectroscopy methods to track ultrafast reactions and electron movement in model molecules, probe organic light emitting diodes, or investigate the recombination of nitrogen and oxygen in the muscle tissue protein myoglobin.

    2
    The first user group at the FXE instrument. No image credit

    The SPB/SFX instrument will be used to gain a better understanding of the shape and function of biomolecules, such as proteins, that are otherwise difficult to study. Several of the seven first experiments at this instrument will focus on method development for these new research opportunities at European XFEL or ways to reduce the amount of precious sample used for the examination of biological processes. Other groups will be studying biological structures and processes such as the Melbourne virus and the water splitting process in photosynthesis.

    3
    The first user group at the SPB/SFX instrument. No image credit

    In this first round of beamtime a total of 14 groups, of up to 80 users each and travelling to Schenefeld from across the globe, will conduct experiments at European XFEL until March 2018. Each group will have about five days of 12 hours of beamtime.

    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 8:19 am on September 4, 2017 Permalink | Reply
    Tags: , Creating 3D digital rocks using x-ray data, , , MicroCT, X-ray Technology   

    From CSIRO blog: “Creating 3D digital rocks using x-ray data” 

    CSIRO bloc

    CSIRO blog

    4 September 2017
    Keirissa Lawson

    1
    3D image of the mineral phase in iron ore. No image credit.

    X-ray vision gave Superman the power to see through solid objects. Mere mortals have also discovered the power of x-rays using them widely in medical and scientific fields to visualise what would be unseen by the naked eye.

    Our scientists have developed a new method using high-resolution x-rays to penetrate solid rock and reveal the minerals and elements hidden inside.

    Called MicroCT, the process works in a similar way to medical CT scans but uses more powerful x-rays to penetrate complex and dense rock material.

    Mineral analysis in 3D

    Coupling this x-ray technique with 3D image analysis has allowed our scientist to create ‘digital rocks’ which show the distribution and characteristics of the elements within the rock sample, without destroying the sample.

    Dr Belinda Godel and her team in Western Australia have been developing this technique for the mineral industry to use across the whole value chain, from exploration through to mineral processing.

    “The MicroCT technology provides crucial data to use for imaging, but the strength in this method relies on its integration with other technologies to provide an accurate 3D characterisation,” Dr Godel says.

    These technologies include optical microscopy, scanning electron microscopy, x-ray fluorescence mapping, laser-ablation inductively couple mass spectrometry (LA-ICP-MS) and electron back-scattered diffraction analysis; all available at our Advanced Characterisation Facility.

    Through our Advanced Characterisation Facility, we deliver high quality and accurate information to improve understanding of mineral resources. We have a range of state-of-the-art analysis and characterisation equipment, which we apply across the minerals value chain from exploration to processing.

    4
    Our specialist characterisation facilities are housed in Perth and Melbourne. ©2012 Damien Smith Photography

    5
    Characterisation image showing strontium. No image credit.

    Traditionally, mineral characterisation is done in two dimensions. By visualising results in three dimensions a more complete picture is revealed, showing shape, size and what minerals are associating with others.

    This information is important not just to show the presence and quantity of a target commodity but also how the ore was formed and how it can be processed.

    With mineral deposits becoming harder to find and more complex to process, 3D digital images showing detailed rock characteristics will benefit the mining industry by helping improve productivity not just in mineral processing and metal production but also in the exploration for new mineral deposits.

    For more information and examples of how this technique has been used in nickel and platinum group metals and iron ore see our recent article from resourceful magazine: Seeing on the inside. Pioneering work to 3D image the inside of rocks will transform the mining industry by removing the guesswork from mineral exploration and processing. JOHN MILLER reports.

    3
    3D image of Mineral Phase in iron ore © CSIRO

    See the full article here .

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    CSIRO campus

    CSIRO, the Commonwealth Scientific and Industrial Research Organisation, is Australia’s national science agency and one of the largest and most diverse research agencies in the world.

    The CSIRO blog is designed to entertain, inform and inspire by generally digging around in the work being done by our terrific scientists, and leaving the techie speak and jargon for the experts.

    We aim to bring you stories from across the vast breadth and depth of our organisation: from the wild sea voyages of our Research Vessel Investigator to the mind-blowing astronomy of our Space teams, right through all the different ways our scientists solve national challenges in areas as diverse as Health, Farming, Tech, Manufacturing, Energy, Oceans, and our Environment.

    If you have any questions about anything you find on our blog, we’d love to hear from you. You can reach us at socialmedia@csiro.au.

    And if you’d like to find out more about us, our science, or how to work with us, head over to CSIRO.au

     
  • richardmitnick 1:01 pm on September 2, 2017 Permalink | Reply
    Tags: , , , , , , , X-ray Technology   

    From STFC: “World’s largest x-ray laser facility is now open to users” 


    STFC

    http://www.stfc.ac.uk/news/worlds-largest-x-ray-laser-facility-is-now-open-to-users/

    1 September 2017
    Becky Parker-Ellis
    STFC Media office
    01793 444564

    1
    The main linac driving the European XFEL, suspended from the ceiling to leave space at floor level, photographed in January 2017. (Image: D Nölle/DESY).

    The global science community is celebrating the official inauguration of the world’s largest X-ray laser at the international research facility, the European XFEL. This event marks the start of user operation after eight years of construction.

    European XFEL is located in Hamburg and Schleswig-Holstein in Germany, and is capable of generating extremely intense X-ray laser flashes that will offer new research opportunities for scientists across the world.

    UK scientists at the Science and Technology Facilities Council (STFC) have played a significant role in the creation of XFEL, by designing and creating the Large Pixel Detector (LPD) – a cutting edge X-ray camera that can capture images of ultrafast processes such as chemical reactions.

    In addition to the LPD, designed and built by STFC’s Technology Division, STFC’s Central Laser Facility is currently building a DiPOLE100 laser for the European XFEL (directly funded by STFC and EPSRC), where it will be used to recreate the conditions found within stars.

    The UK will soon be extending its relationship with XFEL by signing a partnership agreement, allowing UK researchers access to the facility through an STFC-managed subscription. The formal procedures of accession for the UK to join XFEL are underway. In anticipation of this being completed in the coming months the UK has already contributed the majority of its commitment towards the construction costs of the facility.

    Dr Brian Bowsher, Chief Executive of STFC, said: “The UK, through STFC, is already contributing a great deal to this project in terms of equipment and expertise, and we are looking forward to ratifying formally the UK’s involvement in XFEL. XFEL offers many exciting opportunities to the research community and STFC is delighted to support the UK’s involvement with this international facility.

    “Being asked to design and build significant technological infrastructure for XFEL is recognition of the leading reputation STFC’s technology and engineering teams have on the world’s stage.”

    About European XFEL

    The European XFEL is an international research facility of superlatives: 27,000 X-ray flashes per second and a brilliance that is a billion times higher than that of the best conventional X-ray sources will open up completely new opportunities for science. Research groups from around the world will be able to map the atomic details of viruses, decipher the molecular composition of cells, take three-dimensional “photos” of the nanoworld, “film” chemical reactions, and study processes such as those occurring deep inside planets. The construction and operation of the facility is entrusted to the European XFEL GmbH, a non-profit company that cooperates closely with the research centre DESY and other organisations worldwide.

    The company, which has a workforce of about 300 employees, entered in its operating phase on 4 July and has selected the first 14 groups of scientists to carry out their ambitious research projects at the facility from September 2017, including a team from the UK. With construction and commissioning costs of 1.22 billion euro (at 2005 price levels) and a total length of 3.4 kilometres, the European XFEL is one of the largest and most ambitious European research projects to date. At present, 11 countries have signed the European XFEL convention: Denmark, France, Germany, Hungary, Italy, Poland, Russia, Slovakia, Spain, Sweden, and Switzerland. The United Kingdom is in the process of joining.

    STFC and XFEL

    In December 2014 the UK government announced that the UK would invest up to £30M (about 38 M€) to become a full member of the European XFEL as the result of the input received to the BIS Capital Consultation exercise. The UK will become the 12th member of the European XFEL project and STFC is now working with the European XFEL project and the other partners to negotiate UK membership.

    Diamond and XFEL

    The UK, through STFC-funded Diamond Light Source, is also the host for the UK’s XFEL hub. Housed within the existing Diamond infrastructure, the hub will enable users to fully prepare for their experiments with currently operating XFELs and the European XFEL when it comes online in Hamburg in 2017. The UK Hub (which is directly supported by MRC, BBSRC and the Wellcome Trust) will provide support in terms of sample preparation, data processing and training. There will also be a dedicated fibre link from Hamburg to Harwell enabling users to carry out data analysis back in the UK, with support from the UK Hub team.

    From CERN

    The European XFEL is the culmination of a worldwide effort, with European XFEL GmbH being responsible for the construction and operation of the facility, especially the X-ray photon transport and experimental stations, and its largest shareholder DESY leading the construction and operation of the electron linac. The facility joins other major XFELs in the US (LCLS) and Japan (SACLA), and is expected to keep Europe at the forefront of X-ray science for at least the next 20 to 30 years.

    Construction of the €1.2 billion European XFEL began in January 2009, funded by 11 countries, with Germany and Russia as the largest contributors, although no fewer than 17 European institutes contributed in-kind to the accelerator complex. “The European XFEL is the result of intense technological development in a worldwide collaboration that has exceeded expectations,” says Eckhard Elsen, CERN’s Director for Research and Computing. “It is an impressive example of how cutting-edge accelerator research can benefit society, and demonstrates the continuing links between the needs of fundamental research in particle physics and X-ray science.”

    A full account of the European XFEL and its superconducting linac, which appeared in the CERN Courier July/August 2017 issue, can be read here.

    3
    The European XFEL facility in Hamburg (on the right) and Schenefeld (Schleswig-Holstein) (Image: European XFEL)

    See the full STFC article here .
    See the full CERN article here .

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    STFC Hartree Centre

    Helping build a globally competitive, knowledge-based UK economy

    We are a world-leading multi-disciplinary science organisation, and our goal is to deliver economic, societal, scientific and international benefits to the UK and its people – and more broadly to the world. Our strength comes from our distinct but interrelated functions:

    Universities: we support university-based research, innovation and skills development in astronomy, particle physics, nuclear physics, and space science
    Scientific Facilities: we provide access to world-leading, large-scale facilities across a range of physical and life sciences, enabling research, innovation and skills training in these areas
    National Campuses: we work with partners to build National Science and Innovation Campuses based around our National Laboratories to promote academic and industrial collaboration and translation of our research to market through direct interaction with industry
    Inspiring and Involving: we help ensure a future pipeline of skilled and enthusiastic young people by using the excitement of our sciences to encourage wider take-up of STEM subjects in school and future life (science, technology, engineering and mathematics)

    We support an academic community of around 1,700 in particle physics, nuclear physics, and astronomy including space science, who work at more than 50 universities and research institutes in the UK, Europe, Japan and the United States, including a rolling cohort of more than 900 PhD students.

    STFC-funded universities produce physics postgraduates with outstanding high-end scientific, analytic and technical skills who on graduation enjoy almost full employment. Roughly half of our PhD students continue in research, sustaining national capability and creating the bedrock of the UK’s scientific excellence. The remainder – much valued for their numerical, problem solving and project management skills – choose equally important industrial, commercial or government careers.

    Our large-scale scientific facilities in the UK and Europe are used by more than 3,500 users each year, carrying out more than 2,000 experiments and generating around 900 publications. The facilities provide a range of research techniques using neutrons, muons, lasers and x-rays, and high performance computing and complex analysis of large data sets.

    They are used by scientists across a huge variety of science disciplines ranging from the physical and heritage sciences to medicine, biosciences, the environment, energy, and more. These facilities provide a massive productivity boost for UK science, as well as unique capabilities for UK industry.

    Our two Campuses are based around our Rutherford Appleton Laboratory at Harwell in Oxfordshire, and our Daresbury Laboratory in Cheshire – each of which offers a different cluster of technological expertise that underpins and ties together diverse research fields.

    The combination of access to world-class research facilities and scientists, office and laboratory space, business support, and an environment which encourages innovation has proven a compelling combination, attracting start-ups, SMEs and large blue chips such as IBM and Unilever.

    We think our science is awesome – and we know students, teachers and parents think so too. That’s why we run an extensive Public Engagement and science communication programme, ranging from loans to schools of Moon Rocks, funding support for academics to inspire more young people, embedding public engagement in our funded grant programme, and running a series of lectures, travelling exhibitions and visits to our sites across the year.

    Ninety per cent of physics undergraduates say that they were attracted to the course by our sciences, and applications for physics courses are up – despite an overall decline in university enrolment.

     
  • richardmitnick 8:26 am on September 1, 2017 Permalink | Reply
    Tags: , , , Texas Southern University, X-ray Technology   

    From BNL: “Texas Southern University Research Team Advances Safety, Efficiency at NSLS-II” 

    Brookhaven Lab

    August 29, 2017
    Stephanie Kossman

    1
    Mark Harvey (left), Kalifa Kelly (center), and Jesse Zapata (right) conducted research at the inner-shell spectroscopy beamline to improve safety and efficiency at NSLS-II.

    This summer, two student interns and their professor from Texas Southern University (TSU) are making a significant impact on the National Synchrotron Light Source II (NSLS-II), a U.S. Department of Energy Office of Science User Facility at Brookhaven National Laboratory.


    BNL NSLS II

    By collecting and analyzing radiation detector data, the research team is helping to enhance the safety features and reduce the construction costs of future beamlines (experimental stations) built at NSLS-II.

    Jesse Zapata and Kalifa Kelly—two rising seniors at TSU, a historically black college and university—along with their professor, Mark Harvey, came to Brookhaven through the National Science Foundation Louis Stokes Alliances for Minority Participation (NSF-LSAMP) program and Brookhaven’s Office of Educational Programs (OEP). NSF-LSAMP works to increase the number of minority students earning baccalaureate and advanced degrees in science, technology, engineering, and math [STEM].

    “Jesse and Kalifa are high achievers and high performers. My impression is that they are going to end up being leaders in the near future,” Harvey said. “The NSF-LSAMP program, OEP, and NSLS-II provided these students with the opportunity to conduct high quality, first-class research at a premier institution. The unique thing about their research here at Brookhaven is that the students played a major role in the study.”

    After weeks of detailed instruction by Harvey in radiation physics and safety, Zapata and Kelly, in collaboration with NSLS-II staff, designed an experiment to remotely measure radiation fields inside a first optical enclosure (FOE), where NSLS-II’s bright and powerful x-ray light is focused at each beamline. Concrete, lead, and tungsten shielding are used to protect NSLS-II staff from this energy, but shielding the entire FOE with these materials is a costly endeavor. The TSU team, with guidance from staff scientists at NSLS-II, sought to determine how shielding could be localized within the FOE, reducing the amount of material needed while maintaining its overall effectiveness.

    Zapata and Kelly worked with Harvey and NSLS-II staff to design a plan to place detectors in different locations throughout the FOE. “We had a big part in choosing what kind of detectors to use and where to place them,” Zapata said. “This has been a great learning experience for me.”

    The students and Harvey chose specific detectors to place at designated locations based on computerized models of the FOE radiation field created by Brookhaven radiation physicist Mo Benmerrouche. Then, they analyzed the data collected by these detectors over four weeks when NSLS-II was running, and developed a radiation map of the beamline that could be used by staff members at NSLS-II to design localized shielding for future beamlines.

    2
    Kalifa Kelly is shown collecting data at beamline 8-ID, where the TSU team conducted their experiments.

    NSLS-II currently has 28 beamlines in operation or under construction, but the facility is only halfway built out. That means the data measured by the TSU research team could impact the construction of more than 30 additional beamlines. The localized shielding that can now be designed based on the team’s work would reduce the cost of building these beamlines, improve their safety features, and make NSLS-II more attractive for individuals and organizations to come to Brookhaven to build new beamlines and conduct research.

    Harvey, Zapata, and Kelly are not only improving NSLS-II; the students are also gaining a novel skillset that could propel their careers into new and critical areas of science research.

    “There is a huge demand across many fields of science for people who are educated and trained in radiation safety,” said Klaus Attenkofer, program manager of the hard x-ray spectroscopy beamlines at NSLS-II.

    3
    Jesse Zapata is pictured analyzing x-ray detector data that the TSU team used to develop a radiation map.

    At the closing of their summer internship, Zapata and Kelly noted their work at Brookhaven has been a defining moment in their science education.

    “Being able to work with scientists who are experts in their fields has been a phenomenal experience for me.” Kelly said. “This experiment also taught me that just because you have an idea, it doesn’t mean you’re going to stick to that idea. You have to think outside the box when you’re doing research. This experience has pushed me to learn a lot in a short period of time.”

    Data for this project was recorded at the inner-shell spectroscopy (ISS) beamline 8-ID at NSLS-II. The ISS beamline is managed by Eli Stavitski and the hard x-ray spectroscopy program at NSLS-II is managed by Klaus Attenkofer. Additional support for this project was provided by Noel Blackburn, Deana Buckallew, Shawn Buckallew, Sean Carr, Sunil Chitra, Gregory Condemi, Henry Kahnhauser, Robert Lee, Andrew Levine, Subhash Sengupta, Reid Smith, Michelle Tolbert, Geraldine Townsend, Kimberly Wehunt and Bobby Wilson.

    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 7:35 am on September 1, 2017 Permalink | Reply
    Tags: , , , , MEC- Matter in Extreme Conditions, , , , X-ray Technology   

    From SLAC: “Newly Upgraded Laser Allows Scientists to Peer Further Into the Extreme Universe at SLAC’s LCLS” 


    SLAC Lab

    August 15, 2017
    Miyuki Dougherty

    1
    Highly reflective mirrors and telescope lenses in the Matter in Extreme Conditions (MEC) optical laser system are carefully positioned to propagate the instrument’s high-quality laser beams. The laser beams create extreme pressure and temperature conditions in materials that are instantaneously probed using hard X-rays from SLAC’s Linac Coherent Light Source (LCLS). (Dawn Harmer/SLAC National Accelerator Laboratory)

    Tripling the energy and refining the shape of optical laser pulses at the Matter in Extreme Conditions instrument allows researchers to create higher-pressure conditions and explore unsolved fusion energy, plasma physics and materials science questions.

    Scientists at the Department of Energy’s SLAC National Accelerator Laboratory recently upgraded a powerful optical laser system used to create shockwaves that generate high-pressure conditions like those found within planetary interiors. The laser system now delivers three times more energy for experiments with SLAC’s ultrabright X-ray laser, providing a more powerful tool for probing extreme states of matter in our universe.

    Together, the optical and X-ray lasers form the Matter in Extreme Conditions (MEC) instrument at the Linac Coherent Light Source (LCLS).

    SLAC/LCLS

    The high-power optical laser system creates extreme temperature and pressure conditions in materials, and the X-ray laser beam captures the material’s response.

    With this technology, researchers have already examined how meteor impacts shock minerals in the Earth’s crust and simulated conditions in Jupiter’s interior by turning aluminum foil into a warm, dense plasma.

    Higher Intensity and More Controlled Pulse Shapes

    The MEC instrument team received funding from the Office of Fusion Energy Sciences (FES) within the DOE’s Office of Science to double the amount of energy the optical beam can deliver in 10 nanoseconds, from 20 to 40 joules.

    But they went even further.

    “The team exceeded our expectations, an exciting accomplishment for the DOE High Energy Density program and future MEC instrument users,” says Kramer Akli, program manager for High Energy Density Laboratory Plasma at FES.

    The team tripled the amount of energy the laser can deliver in 10 nanoseconds to a spot on a target no bigger than the width of a few human hairs. When focused down to that small area, the laser provides users with intensities up to 75 terawatts per square centimeter.

    “In other terms, the upgraded laser has the same power as 17 Teslas discharging their 100 kilowatt-hour batteries in one second,” says Eric Galtier, a MEC instrument scientist.

    A portion of the energy upgrade can be attributed to the optical laser’s new, homemade diode pumped front-end, designed with the help of Marc Welch, a MEC laser engineer. The scientists also built and automated a system for shaping the laser pulses with extraordinary precision, allowing users substantially greater flexibility and control over the pulse shapes used in their experiments.

    A more powerful and reliable laser means that researchers can study higher pressure regimes and reach conditions relevant to fusion energy studies.

    Simulating the Core of Planets

    The MEC upgrade is promising for many researchers, including Shaughnessy Brennan Brown, a doctoral student in Mechanical Engineering, whose research focuses on high energy density science, which spans chemistry, materials science, and physics. Brennan Brown uses the MEC experimental hutch to drive shock waves through silicon and generate high-pressure conditions that occur in the Earth’s interior.

    “The MEC upgrade at LCLS enables researchers like me to generate exciting, previously-unexplored regimes of exotic matter – such as those found on Mars, our next planetary stepping stone – with crucial reliability and repeatability,” Brennan Brown says.

    Brennan Brown’s research examines the processes by which silicon in Earth’s core rearranges atomically under high temperature and pressure conditions. The thermodynamic properties of these high-pressure states affect our magnetic field, which protects us from the solar wind and allows us to survive on Earth. The laser upgrade will permit Brennan Brown to reach higher pressure and temperature conditions inside her samples, a long-standing goal.

    2
    Inside the MEC vacuum target chamber where researchers create transient states of matter using high-power optical lasers, which are then examined with SLAC’s Linac Coherent Light Source (LCLS) X-rays. (Matt Beardsley/SLAC National Accelerator Laboratory)

    Intensity Plus Precision

    The optical laser amplifies a low-power beam in stages and reaches increasingly high energies. However, the quality of the laser beam and ability to control it diminish during amplification. A low-quality pulse may start and end with a significantly different shape, which is not useful for researchers trying to recreate specific conditions.

    “The initial low energy pulse must have a pristine spatial mode and the properly configured temporal shape – that is, a precise sculpting of the pulse’s power as a function of time – before amplification to produce the laser pulse characteristics needed to enable each users’ experiment,” says Michael Greenberg, the MEC Laser Area Manager.

    Each target is unique and requires a specific energy and pulse shape, making manual tests and adjustments time-consuming. Prior to the upgrade, the team optimized the pulse shape by hand, taking anywhere from a few hours to a few days to properly calibrate it.

    To resolve this issue, Eric Cunningham, a laser scientist at MEC, developed an automated control system to shape the low-powered beam before amplification.

    3
    To demonstrate the MEC laser system’s enhanced ability to tailor the shape of laser pulses, scientists generated pulse shapes that spell out “M-E-C” in a plot of laser intensity vs. time. (Eric Cunningham and Michael Greenberg/SLAC National Accelerator Laboratory)

    “The new system allows for precise tailoring of the pulse shape using a computerized feedback loop system that analyzes the pulses and automatically re-calibrates the laser,” Cunningham said. The new optimizer is a promising system for generating many high-quality pulses in the most accurate and timely manner possible.

    In addition to the improved pulse shapes, the upgraded system deposits energy on samples more consistently from shot to shot, which allows researchers to very closely reproduce extreme states of matter in their samples. As a result, both the data quality and operational efficiency are improved.

    Brennan Brown says it’s the people and technology that make the instrument so successful: “The capability and competency of the laser scientists and engineers at the MEC experimental station offer researchers the technological resources they need to explore unanswered questions of the universe and bring their theories to life.”

    LCLS is a DOE Office of Science User Facility.

    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 1:47 pm on August 28, 2017 Permalink | Reply
    Tags: 2 years of operation and gains, , , , , , X-ray Technology   

    From BNL: “National Synchrotron Light Source II Celebrates Two Years of User Operations” 

    Brookhaven Lab

    August 28, 2017
    Stephanie Kossman

    BNL NSLS II

    In July of 2017, the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory wished a happy second birthday to the National Synchrotron Light Source II (NSLS-II). Located at Brookhaven, NSLS-II is a DOE Office of Science User Facility that provides ultra-bright x-rays for cutting-edge science research.

    During its second year of user operations, NSLS-II reached significant milestones and added several beamlines that offer researchers exciting new capabilities across all fields of science. On July 17, the facility recorded 168 hours (seven days) of continuous beam, showcasing its stability and reliability. And on July 20, NSLS-II delivered user beam at 325 milliamps (mA) for the first time, creating the brightest light the facility has seen so far. Because NSLS-II is in its early years of operations, its level of brightness is still increasing; the goal is to reach 350 mA by the end of September.

    Reaching another milestone, NSLS-II named Joanna Krueger its 1000th lifetime user on June 28. A chemistry professor at the University of North Carolina at Charlotte, Krueger uses NSLS-II to study “sleeping beauty” transposase, an inactive enzyme found in fish that becomes active when inserted into human cells.

    “I am impressed by all the improvements: automation for data collection and fast data reduction,” Krueger said. “I have never seen my data reduced so fast—and I have been doing this work since the mid-nineties. I am very pleased with the facility and the assistance from the beamline staff. It is amazing.”

    BNL NSLS-II

    The great number and diversity of researchers using NSLS-II is a huge success, especially considering the still-growing facility is operating at less than half its capacity. There are currently 20 beamlines (experimental stations) in operation but, when completed, NSLS-II will have 60 beamlines. In other words, at least 60 different experiments could occur at the same time.

    Eight new beamlines were added to NSLS-II during its second year, expanding the facility’s reach into new fields of research and allowing scientists to conduct experiments using new techniques.

    3
    Joanna Krueger was named the 1000th user at NSLS-II on June 28. Krueger uses NSLS-II to study “sleeping beauty” transposase, an inactive enzyme found in fish that becomes active when inserted into human cells.

    The latest beamline to transition into operations was beamline 2-ID, which enables scientists to measure a sample’s response across a range of angles—nearly a full circle around the sample—using high-intensity soft x-rays. This technique is used to determine dynamics of electrons in a wide variety of materials.

    “This beamline will offer world-leading capabilities in terms of soft inelastic x-ray scattering,” said Qun Shen, Deputy Director for Science at NSLS-II. “It is going to be a really cutting-edge technique for studying dynamics and catalysis.”

    Beamline 2-ID is particularly notable for its ability to study light that bounces off individual atoms, but achieving world-class capabilities is the goal for every beamline at NSLS-II.

    Such is the case for 8-BM, a new beamline that uses tender x-rays to image and probe elements that are common in biological structures. 8-BM offers tender energy x-rays—x-rays with an energy from one kiloelectron volt (keV) to four keV—and, amongst other capabilities, allows scientists to study environmental questions – for example, how nuclear materials decay and affect the environment.

    “From five or six keV and up is relatively straightforward to achieve,” Shen said. “But very few beamlines around the world can put emphasis on the tender x-ray energy.”

    Another new beamline, 4-ID, started general user operations in July. This beamline combines the versatile control of beam size, energy, and polarization to enable real-time studies of materials growth and processing, measurements of the atomic structure of functional surfaces and interfaces, and characterization of the electronic order in quantum materials.

    Brookhaven is also partnering with outside institutions to fund the construction and operations of new beamlines at NSLS-II. For example, beamline 17-BM was established through a partnership with the Case Center for Synchrotron Biosciences at Case Western Reserve University. This beamline uses wide-beam x-rays to modify proteins and monitor their structural changes, a “footprinting” technique that was previously unavailable at NSLS-II.

    4
    Scientists Paul Northrup and Syed Khalid are pictured with beamline 8-BM, the new tender energy x-ray beamline at NSLS-II.

    One of NSLS-II’s biggest partners is the National Institute of Standards and Technology (NIST), a government organization that promotes innovation and enhances industrial competitiveness in the U.S. NIST is funding the construction and operations of three beamlines at NSLS-II: two spectroscopy beamlines currently under construction, and beamline 6-BM, which had first light on July 25. At 6-BM, researchers can use x-ray absorption spectroscopy and x-ray diffraction to study how atoms stack together to make materials like batteries and computer chips.

    Other facilities within Brookhaven Lab are also working with NSLS-II on new beamlines, such as beamline 11-BM. This beamline was established through a partnership with Brookhaven’s Center for Functional Nanomaterials.

    “This is where scientists can do x-ray scattering in real time to see how thin films of nanostructures self-organize into something that may be very useful,” Shen said. “Before this beamline came on board, we didn’t have such a dedicated capability.”

    The beamlines at NSLS-II are continuously undergoing changes to improve and expand their functionality. At beamline 3-ID, for example, scientists developed a new imaging method that allows researchers to view an x-ray-transparent sample in real time with quantitative phase measurement.

    In addition to opening new beamlines and making new research techniques available to scientists, NSLS-II’s second year of operations was notable for important scientific breakthroughs. Researchers used beamline 8-ID to develop new cathode materials that could facilitate the mass production of sodium batteries. Another team of researchers used beamline 23-ID-1 to advance the study of high-temperature superconductivity, a phenomena that has baffled scientists for decades. The team discovered that static ordering of electrical charges may cooperate, rather than compete, with superconductivity.

    There is a bright future ahead for NSLS-II. 8 beamlines are currently under construction, and the NSLS-II team is working with the scientific community to develop the next set of beamlines to build. Other future plans for NSLS-II include streamlining logistics for users and making beam time available on multiple beamlines with a single proposal.

    “The last two years have been exciting as we have watched the NSLS-II user community grow and the numbers increase,” said Gretchen Cisco, User Administration Manager at NSLS-II. “We are continuously identifying ways to improve the NSLS-II user experience. Based on user feedback, we are updating the proposal allocation and scheduling system to make it easier to apply for beam time.”

    From its world-class beamlines to the accessibility for its users, NSLS-II has already distinguished itself as a pillar of synchrotron science.

    See the full article here .

    Please help promote STEM in your local schools.

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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 10:56 am on August 21, 2017 Permalink | Reply
    Tags: , Diamond rain, MEC-Matter in Extreme Conditions instrument, , , X-ray Technology   

    From SLAC: “Scientists Create ‘Diamond Rain’ That Forms in the Interior of Icy Giant Planets” 


    SLAC Lab

    August 21, 2017
    Amanda Solliday
    solliday@slac.stanford.edu
    (650) 926-4496

    1
    A cutaway depicts the interior of Neptune (left). In an experiment conducted at the Linac Coherent Light Source, the team studied a plastic simulating compounds formed from methane—a molecule with just one carbon bound to four hydrogen atoms that causes the distinct blue cast of Neptune. Methane forms hydrocarbon (hydrogen and carbon) chains that respond to high pressure and temperature to form “diamond rain” in the interiors of icy giant planets like Neptune. The scientists were able to recreate similar conditions using high-powered optical lasers and watch the small diamonds form in real time with X-rays. (Greg Stewart/SLAC National Accelerator Laboratory)

    In an experiment designed to mimic the conditions deep inside the icy giant planets of our solar system, scientists were able to observe “diamond rain” for the first time as it formed in high-pressure conditions. Extremely high pressure squeezes hydrogen and carbon found in the interior of these planets to form solid diamonds that sink slowly down further into the interior.

    The glittering precipitation has long been hypothesized to arise more than 5,000 miles below the surface of Uranus and Neptune, created from commonly found mixtures of just hydrogen and carbon. The interiors of these planets are similar—both contain solid cores surrounded by a dense slush of different ices. With the icy planets in our solar system, “ice” refers to hydrogen molecules connected to lighter elements, such as carbon, oxygen and/or nitrogen.

    Researchers simulated the environment found inside these planets by creating shock waves in plastic with an intense optical laser at the Matter in Extreme Conditions (MEC) instrument at SLAC National Accelerator Laboratory’s X-ray free-electron laser, the Linac Coherent Light Source (LCLS).

    SLAC/LCLS

    SLAC is one of 10 Department of Energy (DOE) Office of Science laboratories.

    In the experiment, the scientists were able to see that nearly every carbon atom of the original plastic was incorporated into small diamond structures up to a few nanometers wide. On Uranus and Neptune, the study authors predict that diamonds would become much larger, maybe millions of carats in weight. Researchers also think it’s possible that over thousands of years, the diamonds slowly sink through the planets’ ice layers and assemble into a thick layer around the core.

    The research published in Nature Astronomy on August 21.

    “Previously, researchers could only assume that the diamonds had formed,” said Dominik Kraus, scientist at Helmholtz Zentrum Dresden-Rossendorf and lead author on the publication. “When I saw the results of this latest experiment, it was one of the best moments of my scientific career.”

    Earlier experiments that attempted to recreate diamond rain in similar conditions were not able to capture measurements in real time, because we currently can create these extreme conditions under which tiny diamonds form only for very brief time in the laboratory. The high-energy optical lasers at MEC combined with LCLS’s X-ray pulses—which last just femtoseconds, or quadrillionths of a second—allowed the scientists to directly measure the chemical reaction.

    Other prior experiments also saw hints of carbon forming graphite or diamond at lower pressures than the ones created in this experiment, but with other materials introduced and altering the reactions.

    The results presented in this experiment is the first unambiguous observation of high-pressure diamond formation from mixtures and agrees with theoretical predictions about the conditions under which such precipitation can form and will provide scientists with better information to describe and classify other worlds.

    Turning Plastic Into Diamond

    In the experiment, plastic simulates compounds formed from methane—a molecule with just one carbon bound to four hydrogen atoms that causes the distinct blue cast of Neptune.

    The team studied a plastic material, polystyrene, that is made from a mixture of hydrogen and carbon, key components of these planets’ overall chemical makeup.

    In the intermediate layers of icy giant planets, methane forms hydrocarbon (hydrogen and carbon) chains that were long hypothesized to respond to high pressure and temperature in deeper layers and form diamond rain.

    The researchers used high-powered optical laser to create pairs of shock waves in the plastic with the correct combination of temperature and pressure. The first shock is smaller and slower and overtaken by the stronger second shock. When the shock waves overlap, that’s the moment the pressure peaks and when most of the diamonds form, Kraus said.

    During those moments, the team probed the reaction with pulses of X-rays from LCLS that last just 50 femtoseconds. This allowed them to see the small diamonds that form in fractions of a second with a technique called femtosecond X-ray diffraction. The X-ray snapshots provide information about the size of the diamonds and the details of the chemical reaction as it occurs.

    “For this experiment, we had LCLS, the brightest X-ray source in the world,” said Siegfried Glenzer, professor of photon science at SLAC and a co-author of the paper. “You need these intense, fast pulses of X-rays to unambiguously see the structure of these diamonds, because they are only formed in the laboratory for such a very short time.”

    2
    The Matter in Extreme Conditions instrument at SLAC gives scientists the tools to investigate the extremely hot, dense matter at the centers of stars and giant planets. These experiments could help researchers design new materials with enhanced properties and recreate the nuclear fusion process that powers the sun. (SLAC National Accelerator Laboratory)

    Nanodiamonds at Work

    When astronomers observe exoplanets outside our solar system, they are able to measure two primary traits—the mass, which is measured by the wobble of stars, and radius, observed from the shadow when the planet passes in front of a star. The relationship between the two is used to classify a planet and help determine whether it may be composed of heavier or lighter elements.

    “With planets, the relationship between mass and radius can tell scientists quite a bit about the chemistry,” Kraus said. “And the chemistry that happens in the interior can provide additional information about some of the defining features of the planet.”

    Information from studies like this one about how elements mix and clump together under pressure in the interior of a given planet can change the way scientists calculate the relationship between mass and radius, allowing scientists to better model and classify individual planets. The falling diamond rain also could be an additional source of energy, generating heat while sinking towards the core.

    “We can’t go inside the planets and look at them, so these laboratory experiments complement satellite and telescope observations,” Kraus said.

    The researchers also plan to apply the same methods to look at other processes that occur in the interiors of planets.

    In addition to the insights they give into planetary science, nanodiamonds made on Earth could potentially be harvested for commercial purposes—uses that span medicine, scientific equipment and electronics. Currently, nanodiamonds are commercially produced from explosives; laser production may offer a cleaner and more easily controlled method.

    Research that compresses matter, like this study, also helps scientists understand and improve fusion experiments where forms of hydrogen combine to form helium to generate vast amounts of energy. This is the process that fuels the sun and other stars but has yet to be realized in a controlled way for power plants on Earth.

    In some fusion experiments, a fuel of two different forms of hydrogen is surrounded by a plastic layer that reaches conditions similar to the interior of planets during a short-lived compression stage. The LCLS experiment on plastic now suggests that chemistry may play an important role in this stage.

    “Simulations don’t really capture what we’re observing in this field,” Glenzer said. “Our study and others provide evidence that matter clumping in these types of high-pressure conditions is a force to be reckoned with.”

    The research collaboration includes scientists from Helmholtz Zentrum Dresden-Rossendorf in Germany, University of California-Berkeley, Lawrence Livermore National Laboratory, Lawrence Berkeley National Laboratory, GSI Helmholtz Center for Heavy Ion Research in Germany, Osaka University in Japan, Technical University of Darmstadt in Germany, European XFEL, University of Michigan, University of Warwick in the United Kingdom and SLAC.

    The research was supported by DOE’s Office of Science and the National Nuclear Security Administration. LCLS is a DOE Office of Science User Facility.

    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 1:56 pm on August 17, 2017 Permalink | Reply
    Tags: , , , , MPG Institute for Nuclear Physics, , X-ray Technology   

    From MPG Institute for Nuclear Physics: “Sharp x-ray pulses from the atomic nucleus” 

    Max Planck Gesellschaft Institute for Nuclear Physics

    August 17, 2017
    PD Dr. Jörg Evers
    Research Group Leader
    Max Planck Institute for Nuclear Physics, Heidelberg
    Phone:+49 6221 516-177
    joerg.evers@mpi-hd.mpg.de

    Prof. Dr. Thomas Pfeifer
    Max Planck Institute for Nuclear Physics, Heidelberg
    Phone:+49 6221 516-380Fax:+49 6221 516-802
    Thomas.Pfeifer@mpi-hd.mpg.de

    Honorary Professor Dr. Christoph H. Keitel
    Max Planck Institute for Nuclear Physics, Heidelberg
    Phone:+49 6221 516-150Fax:+49 6221 516-152
    keitel@mpi-hd.mpg

    Using a mechanical trick, scientists have succeeded in narrowing the spectrum of the pulses emitted by x-ray lasers.

    X-rays make the invisible visible: they permit the way materials are structured to be determined all the way down to the level of individual atoms. In the 1950s it was x-rays which revealed the double-helix structure of DNA. With new x-ray sources, such as the XFEL free-electron laser in Hamburg, it is even possible to “film” chemical reactions.

    XFEL


    XFEL map

    The results obtained from studies using these new x-ray sources may be about to become even more precise. A team around Kilian Heeg from the Max Planck Institute for Nuclear Physics in Heidelberg has now found a way to make the spectrum of the x-ray pulses emitted by these sources even narrower. In contrast to standard lasers, which generate light of a single colour and wavelength, x-ray sources generally produce pulses with a broad spectrum of different wavelengths. Sharper pulses could soon drive applications that were previously not feasible. This includes testing physical constants and measuring lengths and times even more precisely than can be achieved at present.

    1
    Upgrading x-ray lasers – a mechanical trick can be used to narrow the spectrum of the pulses emitted by x-ray lasers such as the XFEL free electron laser shown here. This would enable x-ray lasers to be used for experiments which would otherwise not be possible, for example testing whether physical constants are really constant. © DESY, Hamburg

    Researchers use light and other electromagnetic radiation for developing new materials at work in electronics, automobiles, aircraft or power plants, as well as for studies on biomolecules such as protein function. Electromagnetic radiation is also the tool of choice for observing chemical reactions and physical processes in the micro and nano ranges. Different types of spectroscopy use different individual wavelengths to stimulate characteristic oscillations in specific components of a structure. Which wavelengths interact with the structure – physicists use the term resonance – tells us something about their composition and how they are constructed; for example, how atoms within a molecule are arranged in space.

    In contrast to visible light, which has a much lower energy, x-rays can trigger resonance not just in the electron shell of an atom, but also deep in the atomic core, its nucleus. X-ray spectroscopy therefore provides unique knowledge about materials. In addition, the resonances of some atomic nuclei are very sharp, in principle allowing extremely precise measurements.

    X-ray sources generate ultra-short flashes with a broad spectrum

    Modern x-ray sources such as the XFEL free electron laser in Hamburg and the PETRA III (Hamburg), and ESRF (Grenoble) synchrotron sources are prime candidates for carrying out such studies.

    DESI Petra III

    ESRF. Grenoble, France

    Free- electron lasers in particular are optimized for generating very short x-ray flashes, which are primarily used to study very fast processes in the microscopic world of atoms and molecules. Ultra short light pulses, however, in turn have a broad spectrum of wavelengths. Consequently, only a small fraction of the light is at the right wavelength to cause resonance in the sample. The rest passes straight through the sample, making spectroscopy of sharp resonances rather inefficient.

    It is possible to generate a very sharp x-ray spectrum – i.e. x-rays of a single wavelength – using filters; however, since this involves removing unused wavelengths, the resulting resonance signal is still weak.

    The new method developed by the researchers in Heidelberg delivers a three to four-fold increase in the intensity of the resonance signal. Together with scientists from DESY in Hamburg and ESRF in Grenoble, Kilian Heeg and Jörg Evers from Christoph Keitel’s Division and a team around Thomas Pfeifer at the Max Planck Institute for Nuclear Physics in Heidelberg have succeeded in making some of the x-ray radiation that would not normally interact with the sample contribute to the resonance signal. They have successfully tested their method on iron nuclei both at the ESRF in Grenoble and at the PETRA III synchrotron of DESY in Hamburg.

    A tiny jolt amplifies the radiation

    The researchers’ approach to amplifying the x-rays is based on the fact that, when x-rays interact with iron nuclei (or any other nuclei) to produce resonance, they are re-emitted after a short delay. These re-emitted x-rays then lag exactly half a wavelength behind that part of the radiation which has passed straight through. This means that the peaks of one wave coincide exactly with the troughs of the other wave, with the result that they cancel each other out. This destructive interference attenuates the X-ray pulses at the resonant wavelength, which is also the fundamental origin of absorption of light.

    “We utilize the time window of about 100 nanoseconds before the iron nuclei re-emit the x-rays,” explains project leader Jörg Evers. During this time window, the researchers move the iron foil by about 40 billionths of a millimetre (0.4 angstroms). This tiny jolt has the effect of producing constructive interference between the emitted and transmitted light waves. “It’s as if two rivers, the waves on one of which are offset by half a wavelength from the waves on the other, meet,” says Evers, “and you shift one of the rivers by exactly this distance.” This has the effect that, after the rivers meet, the waves on the two rivers move in time with each other. Wave peaks coincide with wave peaks and the waves amplify, rather than attenuating, each other. This trick, however, does not just work on light at the resonance wavelengths, but also has the reverse effect (i.e. attenuation) on a broader range of wavelengths around the resonance wavelength. Kilian Heeg puts it like this. “We squeeze otherwise unused x-ray radiation into the resonance.”

    To enable the physicists to move the iron foil fast enough and precisely enough, it is mounted on a piezoelectric crystal. This crystal expands or contracts in response to an applied electrical voltage. Using a specially developed computer program, the Heidelberg-based researchers were able to adjust the electrical signal that controls the piezoelectric crystal to maximize the amplification of the resonance signal.

    Applications in length measurement and atomic clocks

    The researchers see a wide range of potential applications for their new technique. According to Thomas Pfeifer, the procedure will expand the utility of new high-power x-ray sources for high-resolution x-ray spectroscopy. This will enable more accurate modelling of what happens in atoms and molecules. Pfeifer also stresses the utility of the technique in metrology, in particular for high-precision measurements of lengths and the quantum-mechanical definition of time. “With x-rays, it is possible to measure lengths 10,000 times more accurately than with visible light,” explains Pfeifer. This can be used to study and optimize nanostructures such as computer chips and newly developed batteries. Pfeifer also envisages x-ray atomic clocks which are far more precise than even the most advanced optical atomic clocks nowadays based on visible light.

    Not least, better X-ray spectroscopy could enable us to answer one of physics’ great unanswered questions – whether physical constants really are constant or whether they change slowly with time. If the latter were true, resonance lines would drift slowly over time. Extremely sharp x-ray spectra would make it possible to determine whether this is the case over a relatively short period.

    Evers reckons that, once mature, the technique would be relatively easy to integrate into experiments at DESY and ESRF. “It should be possible to make a shoe-box sized device that could be rapidly installed and, according to our calculations, could enable an approximately 10-fold amplification,” he adds.

    Science paper:
    Spectral narrowing of x-ray pulses for precision spectroscopy with nuclear resonances
    http://science.sciencemag.org/content/357/6349/375

    See the full article here .

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    The Max-Planck-Institut für Kernphysik (“MPI for Nuclear Physics” or MPIK for short) is a research institute in Heidelberg, Germany.

    The institute is one of the 80 institutes of the Max-Planck-Gesellschaft (Max Planck Society), an independent, non-profit research organization. The Max Planck Institute for Nuclear Physics was founded in 1958 under the leadership of Wolfgang Gentner. Its precursor was the Institute for Physics at the MPI for Medical Research.

    The Max Planck Society is Germany’s most successful research organization. Since its establishment in 1948, no fewer than 18 Nobel laureates have emerged from the ranks of its scientists, putting it on a par with the best and most prestigious research institutions worldwide. The more than 15,000 publications each year in internationally renowned scientific journals are proof of the outstanding research work conducted at Max Planck Institutes – and many of those articles are among the most-cited publications in the relevant field.

    What is the basis of this success? The scientific attractiveness of the Max Planck Society is based on its understanding of research: Max Planck Institutes are built up solely around the world’s leading researchers. They themselves define their research subjects and are given the best working conditions, as well as free reign in selecting their staff. This is the core of the Harnack principle, which dates back to Adolph von Harnack, the first president of the Kaiser Wilhelm Society, which was established in 1911. This principle has been successfully applied for nearly one hundred years. The Max Planck Society continues the tradition of its predecessor institution with this structural principle of the person-centered research organization.

    The currently 83 Max Planck Institutes and facilities conduct basic research in the service of the general public in the natural sciences, life sciences, social sciences, and the humanities. Max Planck Institutes focus on research fields that are particularly innovative, or that are especially demanding in terms of funding or time requirements. And their research spectrum is continually evolving: new institutes are established to find answers to seminal, forward-looking scientific questions, while others are closed when, for example, their research field has been widely established at universities. This continuous renewal preserves the scope the Max Planck Society needs to react quickly to pioneering scientific developments.

     
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