Tagged: DESY Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 11:39 am on April 18, 2016 Permalink | Reply
    Tags: , , DESY, , , XFEL   

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

    Linear Collider Collaboration header
    Linear Collider Collaboration

    14 April 2016
    Ricarda Laasch

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

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

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

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

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

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

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

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

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

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

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

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

    Linear Collider Colaboration Banner

     
  • richardmitnick 8:31 pm on March 16, 2016 Permalink | Reply
    Tags: , , DESY,   

    From DESY: “Researchers locate particle accelerator of unprecedented energy in the centre of our galaxy” 

    DESY
    DESY

    2016/03/16
    No writer credit found

    Scientists of the H.E.S.S. Observatory have identified an area around the black hole in the centre of the Milky Way that emits intense gamma radiation of extremely high energy. The source of the radiation is an astrophysical accelerator speeding up protons to energies of up to one peta electronvolts (PeV) – more than 100 times higher than the largest and most powerful man-made particle accelerator, the Large Hadron Collider LHC at CERN. The scientists have now published their detailed analysis of recent H.E.S.S. data in the scientific journal Nature. The analysis shows the first identification of a source of cosmic rays with peta-electronvolt energy within the Milky Way: it is very likely the supermassive black hole [Sag A*] at the centre of our galaxy itself.

    Sag A prime
    SAG A*

    For more than 10 years, H.E.S.S. (High Energy Stereoscopic System), a gamma ray telescope in Namibia which is operated by 150 scientists from 12 countries, has mapped the centre of the Milky Way in highest energy gamma rays.

    HESS Cherenko Array
    H.E.S.S. Array

    The gamma rays observed by the researchers are produced by so-called cosmic radiation – high-energy protons, electrons and atomic nuclei, which are accelerated in different places of the universe. Scientists have wondered about the astrophysical sources of this cosmic radiation since its discovery more than a century ago. The problem is that the particles are electrically charged and are therefore deflected in interstellar magnetic fields from their straight path. For this reason, their flight does not point back to its place of production. However, the particles of cosmic radiation often encounter interstellar gas or photons close to their source, producing high-energy gamma rays which reach the earth on a straight path. These gamma rays are used by the scientists of H.E.S.S. Observatory to make the sources of cosmic rays in the sky visible.

    When gamma rays hit the Earth´s atmosphere, they produce short bluish flashes of light that can be detected by large mirror telescopes with fast light sensors at night. With this technique, more than 100 sources of high-energy gamma rays have been discovered in the sky over the past decades. Currently, H.E.S.S. is the most sensitive tool for their detection.

    It is known that cosmic radiation with energies up to about 100 tera electronvolts (TeV) is generated in the Milky Way. However theoretical arguments and the direct measurement of the cosmic radiation suggest that these particles should be accelerated in our galaxy up to energies of at least one peta electronvolt (PeV). In recent years, many extragalactic sources have been discovered that accelerate cosmic rays to multi-TeV energies, but the search for accelerators of the highest-energy cosmic rays in our galaxy remains unsuccessful so far.

    Detailed observations of the centre of the Milky Way, which were carried out with the H.E.S.S. telescopes during the past 10 years, now provide the first answers. “We have located an astrophysical accelerator accelerating protons to energies of up to one peta electronvolts, and that continuously over at least 1000 years,” says Prof. Christian Stegmann, head of DESY in Zeuthen and former spokesperson of the H.E.S.S. Collaboration.

    Already during the first years of observation since 2002 H.E.S.S. had detected a strong compact source and an extended band of diffuse highest-energy gamma rays in the galactic centre. Evidence of this diffuse radiation, which covers an area of about 500 light years across, was already a clear indication of a source of cosmic rays in this region; proof of the source itself remained unfulfilled for the researchers. A significantly larger amount of observational data together with advances in analytical techniques have made it now possible to measure for the first time both the spatial distribution as well as the energy of the cosmic rays.

    Although the central region of our Milky Way hosts many objects that can generate high-energy cosmic rays, for instance a supernova remnant, a pulsar wind nebulae and a compact star clusters, the measurement of gamma rays from the galactic centre provides strong evidence that the supermassive black hole at the galactic centre itself accelerates protons to an energy of up to one PeV.

    Supernova remnant Crab nebula
    Crab supernova remnant

    “Our data show that the observed glow of gamma rays around the galactic centre is symmetrical,” says H.E.S.S. researcher Stefan Klepser from Zeuthen. “The gamma rays are of a high energy and concentrated towards the centre, which suggests that they must be the echo of a huge particle accelerator which is located in the centre of this glow.” Prof. Stegmann adds that “several possible acceleration regions can be considered, either in the immediate vicinity of the black hole, or further away, where a fraction of the material falling into the black hole is ejected back into the environment, potentially initiating the acceleration of particles.“

    However, the analysis of the measurements also shows that this source alone cannot account for the total flux of cosmic rays detected on Earth. “If, however, our central black hole has been more active in the past”, the researchers argue, “then it might actually be responsible for the entire bulk of today´s galactic cosmic rays”. If their assumption is correct, the 100-year-old mystery of the origin of cosmic rays would be solved.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    desi

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

     
  • richardmitnick 1:01 pm on March 2, 2016 Permalink | Reply
    Tags: , DESY, ,   

    From XFEL: “All segments of first light-generating system installed in European XFEL” 

    XFEL bloc

    European XFEL

    01 March 2016
    No writer credit

    Facility reaches prominent milestone

    In the metropolitan area of Hamburg, the installation of the 35 segments of the first of three X-ray light producing components of the European XFEL has been completed. Set into one of the facility’s tunnels, the segments are the core part of three systems called undulators, which are each up to 210 metres long and will produce X-ray laser light exceeding the intensity of conventional X-ray sources by a billion times.

    XFEL Undulator
    XFEL undulator. No image credit.

    These pulses of X-ray radiation are the basis for new revolutionary experimental techniques that will allow scientists to study the nanocosmos, with applications in many fields including biochemistry, astrophysics, and materials science. The undulator installation is a major step towards the completion of the European XFEL, a 3.4 km-long X-ray free-electron laser facility that will be the world’s brightest X-ray source when completed. It is also one of Europe’s largest research projects and is due to open to users for research in 2017.

    “With the 35 segments of the first undulator beam line in place, we have clearly reached a very important milestone in the construction of our facility”, says European XFEL Managing Director Prof. Massimo Altarelli. “The X-ray flashes produced in these systems are the basis for the future research at the European XFEL. We are looking forward to 2017, when they will be used to investigate the smallest details of the structure and function of matter in the molecular world.”

    Each of the 35 segments is 5 m long, weighs 7.5 t, and is composed of two girders facing one another, each holding a line of alternating strong permanent magnets. When accelerated electrons pass through the field of alternating polarity generated by the magnets, ultrashort flashes of X-ray laser light are produced. Components between adjacent segments help ensure a consistent magnetic field between them, and control systems allow mechanical movement of components within the undulator, which allows generation of a large spectrum of photon wavelengths.

    Design, development, and prototyping work started approximately eight years ago in a joint collaboration with DESY, European XFEL’s largest shareholder. The same technology is also used in a number of projects at DESY, including the X-ray free-electron laser FLASH and the PETRA III storage ring light source.

    DESY FLASH
    DESY FLASH

    DESY Petra III interior
    DESY PETRA III

    The undulator system was built through a multinational collaboration. The challenging production involved DESY and Russian, German, Swiss, Italian, Slovenian, Swedish, and Chinese institutes and companies under the leadership of the undulator group of the European XFEL. This includes a number in-kind contributions such as electromagnets for the electron beamline designed and manufactured at several institutes in Russia and tested in Sweden; temperature monitoring units from the Manne Siegbahn Laboratory in Sweden; and movers, phase shifters, and control systems designed and manufactured by the research centre CIEMAT in Spain.

    “This was a true synergetic collaboration”, says Joachim Pflüger, group leader of the European XFEL undulator group. “The resources and experience of DESY were essential for the development of the undulator systems. Now there is a great mutual benefit!”

    This first completed undulator will generate short-wavelength “hard” X-rays that will be used for experiments with a focus on structural biology and ultrafast chemistry. All three of the undulators planned for the starting phase of the European XFEL will be operational by the end of 2016.

    How the XFEL undulator works
    How the undulator works.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    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 2:07 pm on February 10, 2016 Permalink | Reply
    Tags: , Biomolecules, , DESY, ,   

    From DESY: “New method opens crystal clear views of biomolecules” 

    DESY
    DESY

    2016/02/11
    No writer credit found

    A scientific breakthrough gives researchers access to the blueprint of thousands of molecules of great relevance to medicine and biology. The novel technique, pioneered by a team led by DESY scientist Professor Henry Chapman from the Center for Free-Electron Laser Science CFEL and reported this week in the scientific journal Nature, opens up an easy way to determine the spatial structures of proteins and other molecules, many of which are practically inaccessible by existing methods. The structures of biomolecules reveal their modes of action and give insights into the workings of the machinery of life. Obtaining the molecular structure of particular proteins, for example, can provide the basis for the development of tailor-made drugs against many diseases. “Our discovery will allow us to directly view large protein complexes in atomic detail,” says Chapman, who is also a professor at the University of Hamburg and a member of the Hamburg Centre for Ultrafast Imaging CUI.

    Dimer crystals Detec of complex biomolecules like that of the photosystem II molecule shown here
    Slightly disordered crystals of complex biomolecules like that of the photosystem II molecule shown here produce a complex continous diffraction pattern (right, the disorder is greatly exaggerated) under X-ray light that contains far more information than the so-called Bragg peaks of a strongly ordered crystal alone (left). Credit: DESY, Eberhard Reimann

    To determine the spatial structure of a biomolecule, scientists mainly rely on a technique called crystallography. The new work offers a direct route to “read” the atomic structure of complex biomolecules by crystallography without the usual need for prior knowledge and chemical insight. “This discovery has the potential to become a true revolution for the crystallography of complex matter,” says the chairman of DESY’s board of directors, Professor Helmut Dosch.

    In crystallography, the structure of a crystal and of its constituents can be investigated by shining X-rays on it. The X-rays scatter from the crystal in many different directions, producing an intricate and characteristic pattern of numerous bright spots, called Bragg peaks (named after the British crystallography pioneers William Henry and William Lawrence Bragg). The positions and strengths of these spots contain information about the structure of the crystal and of its constituents. Using this approach, researchers have already determined the atomic structures of tens of thousands of proteins and other biomolecules.

    But the method suffers from two significant barriers, which make structure determination extremely difficult or sometimes impossible. The first is that the molecules must be formed into very high quality crystals. Most biomolecules do not naturally form crystals. However, without the necessary perfect, regular arrangement of the molecules in the crystal, only a limited number of Bragg peaks are visible. This means the structure cannot be determined, or at best only a fuzzy “low resolution” facsimile of the molecule can be found. This barrier is most severe for large protein complexes such as membrane proteins. These systems participate in a range of biological processes and many are the targets of today’s drugs. Great skill and quite some luck are needed to obtain high-quality crystals of them.

    Extreme Sudoku in three dimensions

    The second barrier is that the structure of a complex molecule is still extremely difficult to determine, even when good diffraction is available. “This task is like extreme Sudoku in three dimensions and a million boxes, but with only half the necessary clues,” explains Chapman. In crystallography, this puzzle is referred to as the phase problem. Without knowing the phase – the lag of the crests of one diffracted wave to another – it is not possible to compute an image of the molecule from the measured diffraction pattern. But phases can’t be measured. To solve the tricky phase puzzle, more information must be known than just the measured Bragg peaks. This additional information can sometimes be obtained by X-raying crystals of chemically modified molecules, or by already knowing the structure of a closely-related molecule.

    When thinking about why protein crystals do not always “diffract”, Chapman realised that imperfect crystals and the phase problem are linked. The key lies in a weak “continuous” scattering that arises when crystals become disordered. Usually, this non-Bragg, continuous diffraction is thought of as a nuisance, although it can be useful for providing insights into vibrations and dynamics of molecules. But when the disorder consists only of displacements of the individual molecules from their ideal positions in the crystal then the “background” takes on a much more complex character – and its rich structure is anything but diffuse. It then offers a much bigger prize than the analysis of the Bragg peaks: the continuously-modulated “background” fully encodes the diffracted waves from individual “single” molecules.

    “If you would shoot X-rays on a single molecule, it would produce a continuous diffraction pattern free of any Bragg spots,” explains lead author Dr. Kartik Ayyer from Chapman’s CFEL group at DESY. “The pattern would be extremely weak, however, and very difficult to measure. But the ‘background’ in our crystal analysis is like accumulating many shots from individually-aligned single molecules. We essentially just use the crystal as a way to get a lot of single molecules, aligned in common orientations, into the beam.” With imperfect, disordered crystals, the continuous diffraction fills in the gaps and beyond the Bragg peaks, giving vastly more information than in normal crystallography. With this additional gain in information, the phase problem can be uniquely solved without having to resort to other measurements or assumptions. In the analogy of the Sudoku puzzle, the measurements provide enough clues to always arrive at the right answer.

    The best crystals are imperfect crystals

    This novel concept leads to a paradigm shift in crystallography — the most ordered crystals are no longer the best to analyse with the novel method. Instead, the best crystals are imperfect crystals. “For the first time we have access to single molecule diffraction – we have never had this in crystallography before,” he explains. “But we have long known how to solve single-molecule diffraction if we could measure it.” The field of coherent diffractive imaging, spurred by the availability of laser-like beams from X-ray free-electron lasers, has developed powerful algorithms to directly solve the phase problem in this case, without having to know anything at all about the molecule. “You don’t even have to know chemistry,” says Chapman, “but you can learn it by looking at the three-dimensional image you get.”

    To demonstrate their novel analysis method, the Chapman group teamed up with the group of Professor Petra Fromme from the Arizona State University (ASU), and other colleagues from ASU, University of Wisconsin, the Greek Foundation for Research and Technology – Hellas FORTH, and SLAC National Accelerator Laboratory in the U.S. They used the world’s most powerful X-ray laser LCLS at SLAC to X-ray imperfect microcrystals of a membrane protein complex called Photosystem II that is part of the photosynthesis machinery in plants.

    SLAC LCLS Inside
    Inside LCLS

    Including the continuous diffraction pattern into the analysis immediately improved the spatial resolution around a quarter from 4.5 Ångström to 3.5 Ångström (an Ångström is 0.1 nanometres). The obtained image gave fine definition of molecular features that usually require fitting a chemical model to see. “That is a pretty big deal for biomolecules,” explains co-author Dr. Anton Barty from DESY. “And we can further improve the resolution if we take more patterns.” The team had only a few hours of measuring time for these experiments, while full-scale measuring campaigns usually last a couple of days.

    The scientists hope to obtain even clearer and higher resolution images of photosystem II and many other macromolecules with their new technique. “This kind of continuous diffraction has actually been seen for a long time from many different poorly-diffracting crystals,” says Chapman. “It wasn’t understood that you can get structural information from it and so analysis techniques suppressed it. We’re going to be busy to see if we can solve structures of molecules from old discarded data.”

    Reference:
    Macromolecular diffractive imaging using imperfect crystals; Kartik Ayyer et al.; Nature (2016); DOI: 10.1038/nature16949

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    desi

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

     
  • richardmitnick 9:16 am on February 5, 2016 Permalink | Reply
    Tags: , DESY, ,   

    From DESY: “Scientists film exploding nanoparticles” 

    DESY
    DESY

    2016/02/05
    No writer credit found

    Imaging nanoscale dynamics with unparalleled detail and speed

    Using a super X-ray microscope, an international research team has “filmed” the explosion of single nanoparticles. The team led by Tais Gorkhover from Technische Universität Berlin, currently working at the SLAC National Accelerator Laboratory in the U.S. as a fellow of the Volkswagen Foundation, and Christoph Bostedt from the Argonne National Laboratory and Northwestern University has managed to combine a temporal resolution of 100 femtoseconds and a spatial resolution of eight nanometres for the first time. A nanometre is a billionth of a metre, and a femtosecond is a mere quadrillionth of a second. For their experiments, the scientists used the so-called free-electron X-ray laser LCLS.

    SLAC LCLS Inside
    LCLS at SLAC

    The exposure time of the individual images was so short that the rapidly moving particles in the gas phase appeared frozen in time. Therefore, they did not have to be fixed on substrates as it is commonly done in other microscopy approaches. The team, including researchers from the Center for Free-Electron Laser Science CFEL at DESY, reports its results in the scientific journal Nature Photonics.

    Xenon nanoparticle exploding
    Three states of an exploding xenon nanoparticle. The ultra short flashes of the X-ray laser record these states as a so-called diffraction pattern. From these, the state of the sample can be calculated. Credit: Tais Gorkhover/SLAC

    Most imaging approaches are severely limited when a combination of high spatial resolution and extreme shutter speed is required. Ultrafast optical approaches have a rather coarse resolution due to the long wavelength. Conversely, electron microscopy can yield ultrahigh resolution but demands a rather long exposure time and it requires the particles being fixed to substrates. Therefore ultrafast processes in free nanometre-sized particles cannot be directly imaged with conventional methods. However, the ability to image and understand the dynamics in nanostructures and aggregates is of relevance in many fields, ranging from climate models to nanotechnology.

    The properties and dynamics of nanoparticles can significantly change when they are deposited on a substrate. To avoid any modification, the particles, made of frozen xenon and with a diameter of around 40 nanometres, were imaged during their flight through a vacuum chamber. “Using the intense light of an infrared laser, the nanoparticles where superheated and exploded,” explains DESY scientist Jochen Küpper, who is also a professor at the University of Hamburg and a member of the Hamburg Centre for Ultrafast Imaging (CUI). The explosion was imaged with ultrafast X-ray flashes at different time steps. Küpper’s group helped to implement this so-called pump-probe technique. “The experiment was repeated over and over with a new nanoparticle every time and slightly increased delay of the X-ray flash,” reports Lotte Holmegaard from Küpper’s CFEL group. Subsequently the images were assembled to a „movie“.

    „To our big surprise the exploding particles appeared to be shrinking with time instead of expanding as intuitively expected“ says Gorkhover. This unexpected result could be explained with theoretical models that describe the explosion as a melting process starting on the surface instead of a homogenous expansion. In this process, the solid part of the particle’s core gets smaller and smaller what causes the illusion of a shrinking particle.

    Another very interesting aspect of this new imaging approach is that it is possible to directly image the dynamics in single, free nanoparticles. Most time resolved studies are based on ensembles of many particles and averaging statements in which some important differences such as size and shapes of the particles get lost. “We have already demonstrated the importance to look at one particle at a time in earlier static experiments. Now this approach is also available for time-resolved studies,” says Gorkhover.

    “Our experiments yield unprecedented insight into the non-equilibrium physics of superheated nanoparticles. Moreover, they open the door for a multitude of new experiments where the ultrafast dynamics of small samples is important.“ explains Bostedt. Such dynamics may be of relevance in the formation of aerosols which are of major importance in climate models as they are in a large part responsible for absorption and reflection of sunlight. They may also be interesting for research on laser driven fusion in small targets or the rapidly developing area of nanoplasmonics in which the properties of nanoparticles are manipulated with intense light fields.

    Reference:
    Femtosecond and nanometre visualization of structural dynamics in superheated nanoparticles; Tais Gorkhover, Christoph Bostedt et al.; „Nature Photonics“, 2016; DOI: 10.1038/NPHOTON.2015.264

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    desi

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

     
  • richardmitnick 9:03 pm on December 28, 2015 Permalink | Reply
    Tags: , , , DESY, , ,   

    From DESY: “ERC Starting Grant for characterising the Higgs boson” 

    DESY
    DESY

    2015/12/28
    No writer credit found

    Temp 1
    No image credit found

    Kerstin Tackmann, a physicist at DESY, is to receive over 1.3 million euros from the European Research Council (ERC) in order to carry out research aimed at a more detailed characterisation of the Higgs boson.

    CERN ATLAS Higgs Event
    Higgs event at ATLAS

    She will use a starting grant to set up a research group to investigate the properties of the Higgs boson in great detail, as part of the international ATLAS Collaboration.

    CERN ATLAS New
    ATLAS

    These measurements are an important step towards identifying whether the particle fits the Standard Model of particle physics. The 5-year project is scheduled to begin in 2016.

    Ever since particle physicists working on the big LHC experiments ATLAS and CMS announced, in 2012, the discovery of a particle whose properties corresponded to those of the elusive Higgs boson, particle physics has faced an extremely exciting mystery: does this Higgs boson fit the Standard Model of particle physics, the currently accepted description of the elementary particles that make up matter and the forces acting between them, or will it open the path to a new, higher-level theory.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    CERN CMS Detector
    CMS

    CERN CMS Event
    CMS Higgs event

    Standard model with Higgs New
    Standard Model of Particle Physics

    Using the data available so far, scientists have already been able to determine the particle’s mass of around 125 gigaelectronvolts (GeV) and its spin of zero to a fairly high degree of accuracy. To obtain even more precise information about additional properties of the particle, the researchers need to analyse far more data from proton-proton collisions in the LHC. They are particularly interested in finding out exactly how the Higgs field, of which the Higgs boson is an indication, lends elementary particles their mass. To answer this question, they have started to analyse the collision data from “LHC Run 2”, which began this summer and which is expected to produce about 15 times as many Higgs bosons as the LHC’s previous run. The analysis of this large amount of collision data will allow far more reliable conclusions to be drawn.

    Kerstin Tackmann intends to devote herself to these questions together with two post-docs and three PhD students, and will be analysing the collisions from Run 2 of the ATLAS detector in great detail. They will be working as part of the ATLAS Collaboration, involving hundreds of scientists from all over the world. Her group is going to concentrate on measuring the kinematic properties of Higgs boson production. The focus will lie especially on the decay of the Higgs boson into two photons or four leptons, which allows very accurate measurements to be made. This is where deviations from the precise predictions of the Standard Model could occur, should the Higgs boson not fit the Standard Model.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    desi

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

     
  • richardmitnick 9:08 am on November 17, 2015 Permalink | Reply
    Tags: , , DESY, Helmholtz Young Investigators Groups   

    From DESY: “Three Helmholtz Young Investigators Groups for DESY” 

    DESY
    DESY

    2015/11/11

    The Helmholtz Association has awarded DESY grants to set up three new Young Investigators Groups. With annual funds of 250 000 euros each, three young scientists can set up their own research groups at DESY over a period of five years. Altogether, the Helmholtz Association is supporting 17 new Young Investigators Groups at its 18 centres. “I am very happy that no fewer than three of our candidates were able to convince the jury with their projects. This shows the outstanding quality of the young scientists we have at DESY”, says Prof. Helmut Dosch, chairman of DESY’s Board of Directors. DESY itself will be supplying half the overall funds in each case.

    1

    In her group, Dr. Sadia Bari will be developing new methods for examining biomolecules. For this purpose, these proteins are to be placed in the beam of a bright X-ray source using a technique known as electrospray ionisation, making it possible to study them in a defined state without any substrate or solvent. Scientists are hoping that this will allow a range of fundamental questions to be answered, including the nature of the radiation damage that occurs in biological cells during medical radiation treatment, and the electrical charge transfer that occurs, for example, during photosynthesis in plants.

    Dr. Martin Beye was awarded the grant to develop new methods of investigation in materials science using X-rays. So-called soft X-rays, which have less energy than hard X-rays, are particularly suitable for studying active surfaces and boundary layers, because they are specifically sensitive to the active chemical elements in a compound. In this project, methods from optical laser spectroscopy are to be adapted for use with X-rays. The scientists are hoping that this will extend the scope of their analytical methods to a similar degree to that achieved through the introduction of optical lasers.

    Dr. Sarah Heim is setting up a group of young investigators to search for dark matter and other features of the so-called new physics, using the ATLAS detector at the world’s largest particle accelerator, the LHC. The scientists want to use two different approaches to look for candidates for the hitherto completely mysterious dark matter: on the one hand via the decay of the Higgs boson, which was discovered in 2012 at the LHC, into invisible particles which do not leave a trace in the detector; on the other hand indirectly by comparing the properties of the Higgs particle with the predictions of the so-called standard model of particle physics. DESY has various research groups involved in experiments at the LHC. Heim’s Young Investigators Group will be part of the ATLAS group at DESY.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    desi

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

     
  • richardmitnick 9:43 am on November 3, 2015 Permalink | Reply
    Tags: , , DESY, EuPRAXIA Plasma Acceleraotr   

    From DESY: “EU funds design study for European plasma accelerator” 

    DESY
    DESY

    2015/11/02

    Three million euros for European Plasma Research Accelerator with eXcellence In Applications (EuPRAXIA) project

    The European Union supports the development of a novel plasma particle accelerator with three million euros from the Horizon2020 program. The EU project EuPRAXIA (European Plasma Research Accelerator with eXcellence In Applications) will produce a design study for a European plasma research accelerator focussing on applications of the new technology. Plasma acceleration promises to shrink costs and size of particle accelerators for science, medical applications and industry significantly.

    1

    “EuPRAXIA will define the missing step towards a new generation of plasma accelerators with the potential for dramatically reduced size and cost,” said EuPRAXIA coordinator Ralph Assmann from DESY. “It will ensure that Europe is kept at the forefront of accelerator-based science and applications.” The EuPRAXIA consortium includes 16 laboratories and universities from five EU member states. In addition, it includes 18 associated partners from eight countries, involving leading institutes in the EU, Japan, China and the United States.

    Particle accelerators have evolved over the last 90 years into powerful and versatile machines for discoveries and applications. Today some 30,000 accelerators are operated around the world, among those some of the largest machines built by human mankind. A new technology for particle acceleration has emerged and has demonstrated accelerating fields a thousand times beyond those presently used: Plasma acceleration uses electrically charged plasmas, generated by strong lasers, instead of the usual radio frequency used in conventional accelerators, to boost particles like electrons to high energies.

    2
    Image of a plasma cell. Credit: Heiner Müller-Elsner/DESY

    By the end of 2019, EuPRAXIA will produce a conceptual design report for the worldwide first five Giga-Electronvolts plasma-based accelerator with industrial beam quality and dedicated user areas. EuPRAXIA is the required intermediate step between proof-of-principle experiments and versatile ultra-compact accelerators for industry, medicine or science, e.g. at the energy frontier of particle physics as a plasma linear collider.

    The study will design accelerator technology, laser systems and feedbacks for improving the quality of plasma-accelerated electron beams. Two user areas will be developed for a novel free-electron laser, high-energy physics and other applications. An implementation model will be proposed, including a comparative study of possible sites in Europe, a cost estimate and a model for distributed construction but installation at one central site. As a new large research infrastructure, EuPRAXIA would place Europe at the forefront of the development of novel accelerators driven by the world’s most powerful lasers from European industry in the 2020’s.

    The EuPRAXIA consortium has the following participants: Centre National de la Recherche Scientifique (CNRS), Commissariat à l’Énergie Atomique et aux énergies alternatives (CEA) and Synchrotron SOLEIL from France, DESY and the University of Hamburg from Germany, Istituto Nazionale di Fisica Nucleare (INFN), Consiglio Nazionale delle Ricerche (CNR), Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenible (ENEA) and Sapienza Universita di Roma from Italy and Instituto Superior Técnico (IST) from Portugal, Science & Technology Facilities Council (STFC), University of Manchester, University of Liverpool, University of Oxford, University of Strathclyde and Imperial College London from the UK.

    Associated partners are: Jiaotong University Shanghai and Tsingua University Beijing from China, Extreme Light Infrastructures – Beams (ELI-B) in Czech Republic, University of Lille in France, High Energy Accelerator Research Organization (KEK), Kansai Photon Science Institute, Japan Atomic Energy Agency, Osaka University and RIKEN Spring-8 Center from Japan, Helmholtz-Institut Jena, Helmholtz-Zentrum Dresden-Rossendorf and Ludwig-Maximillians-Universität München from Germany, Wigner Research Center of the Hungarian Academy of Science in Hungary, University of Lund in Sweden, European Organization for Nuclear Research (CERN) in Switzerland, Center for Accelerator Science and Education at Stony Brook University & Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL), SLAC National Accelerator Laboratory and University of California at Los Angeles (UCLA) in the U.S.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    desi

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

     
  • richardmitnick 3:25 pm on October 6, 2015 Permalink | Reply
    Tags: , DESY, ,   

    From DESY: “Physicists shrink particle accelerator” 

    DESY
    DESY

    2015/10/06
    No Writer Credit

    1
    Terahertz accelerator modules easily fit into two fingers. Credit: DESY/Heiner Müller-Elsner

    An interdisciplinary team of researchers has built the first prototype of a miniature particle accelerator that uses terahertz radiation instead of radio frequency structures. A single accelerator module is no more than 1.5 centimetres long and one millimetre thick. The terahertz technology holds the promise of miniaturising the entire set-up by at least a factor of 100, as the scientists surrounding DESY’s Franz Kärtner from the Center for Free-Electron Laser Science (CFEL) point out. They are presenting their prototype, that was set up in Kärtner’s lab at the Massachusetts Institute of Technology (MIT) in the U.S., in the journal Nature Communications. The authors see numerous applications for terahertz accelerators, in materials science, medicine and particle physics, as well as in building X-ray lasers. CFEL is a cooperation between DESY, the University of Hamburg and the Max Planck Society.

    In the electromagnetic spectrum, terahertz radiation lies between infrared radiation and microwaves. Particle accelerators usually rely on electromagnetic radiation from the radio frequency range; DESY’s particle accelerator PETRA III, for example, uses a frequency of around 500 megahertz.

    DESI Petra III interior
    DESY/PETRA III

    The wavelength of the terahertz radiation used in this experiment is around one thousand times shorter. “The advantage is that everything else can be a thousand times smaller too,” explains Kärtner, who is also a professor at the University of Hamburg and at MIT, as well as being a member of the Hamburg Centre for Ultrafast Imaging (CUI), one of Germany’s Clusters of Excellence.

    For their prototype the scientists used a special microstructured accelerator module, specifically tailored to be used with terahertz radiation. The physicists fired fast electrons into the miniature accelerator module using a type of electron gun provided by the group of CFEL Professor Dwayne Miller, Director at the Max Planck Institute for the Structure and Dynamics of Matter and also a member of CUI. The electrons were then further accelerated by the terahertz radiation fed into the module. This first prototype of a terahertz accelerator was able to increase the energy of the particles by seven kiloelectronvolts (keV).

    “This is not a particularly large acceleration, but the experiment demonstrates that the principle does work in practice,” explains co-author Arya Fallahi of CFEL, who did the theoretical calculations. “The theory indicates that we should be able to achieve an accelerating gradient of up to one gigavolt per metre.” This is more than ten times what can be achieved with the best conventional accelerator modules available today. Plasma accelerator technology, which is also at an experimental stage right now, promises to produce even higher accelerations, however it also requires significantly more powerful lasers than those needed for terahertz accelerators.

    The physicists underline that terahertz technology is of great interest both with regard to future linear accelerators for use in particle physics, and as a means of building compact X-ray lasers and electron sources for use in materials research, as well as medical applications using X-rays and electron radiation. “The rapid advances we are seeing in terahertz generation with optical methods will enable the future development of terahertz accelerators for these applications,” says first author Emilio Nanni of MIT. Over the coming years, the CFEL team in Hamburg plans to build a compact, experimental free-electron X-ray laser (XFEL) on a laboratory scale using terahertz technology. This project is supported by a Synergy Grant of the European Research Council.

    So-called free-electron lasers (FELs) generate flashes of laser light by sending high-speed electrons from a particle accelerator down an undulating path, whereby these emit light every time they are deflected. This is the same principle that will be used by the X-ray laser European XFEL, which is currently being built by an international consortium, reaching from the DESY Campus in Hamburg to the neighbouring town of Schenefeld, in Schleswig-Holstein. The entire facility will be more than three kilometres long and will be the best and most modern of its kind after completion.

    The experimental XFEL using terahertz technology is expected to be less than a metre long. “We expect this sort of device to produce much shorter X-ray pulses lasting less than a femtosecond”, says Kärtner. Because the pulses are so short, they reach a comparable peak brightness to those produced by larger facilities, even if there is significant less light in each pulse. “With these very short pulses we are hoping to gain new insights into extremely rapid chemical processes, such as those involved in photosynthesis.”

    Developing a detailed understanding of photosynthesis would open up the possibility of implementing this efficient process artificially and thus tapping into increasingly efficient solar energy conversion and new pathways for CO2 reduction. Beyond this, researchers are interested in numerous other chemical reactions. As Kärtner points out, “photosynthesis is just one example of many possible catalytic processes we would like to investigate.” The compact XFEL can be potentially also used to seed pulses in large scale facilities to enhance the quality of their pulses. Also, certain medical imaging techniques could benefit from the enhanced characteristics of the novel X-ray source.

    Reference:
    „Terahertz-driven linear electron acceleration“; Emilio A. Nanni, Wenqian R. Huang, Kyung-Han Hong, Koustuban Ravi, Arya Fallahi, Gustavo Moriena, R. J. Dwayne Miller & Franz X. Kärtner; Nature Communications, 2015; DOI: 10.1038/NCOMMS9486

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    desi

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

     
  • richardmitnick 9:31 am on September 18, 2015 Permalink | Reply
    Tags: , DESY, ,   

    From DESY: “X-rays reveal electron puddles in ceramic superconductors” 

    DESY
    DESY

    2015/09/17
    No Writer Credit

    1
    The superconducting current (red tubes) running in the interstitial space between puddles of electronic crystals. Credit: Alessandro Ricci/DESY

    Using high-energy X-rays, an international team of scientists has discovered a surprising inner structure of a special class of superconductors: Within these so-called high-temperature superconductors, the electrons form puddles of varying sizes throughout the material. This finding helps to understand the microscopic origin of high-temperature superconductivity that is still not fully known. The team reports its observations in the journal Nature.

    Superconductors are materials that can transport electric currents completely without loss. This feature makes them attractive for a wide spectrum of technical applications. Unfortunately, classic superconductors have to be cooled down to temperatures near absolute zero (minus 273,15 degrees Celsius) to work. This limits their application to a few special purposes. However, a couple of decades ago it was discovered that certain ceramics can become superconducting at much higher temperatures. Despite their name, these high-temperature superconductors still have to be cooled down, but not as much as classic superconductors. Some copper oxides (cuprates) can become superconducting at minus 170 degrees Celsius, for instance.

    High-temperature superconductors work different from classic superconductors, and with a better understanding of their function, the design of a room temperature superconductor might become possible one day. To investigate the microstructure of a high-temperature cuprate superconductor (HgBa2CuO4+y), the team led by Alessandro Ricci of DESY, Antonio Bianconi of the Rome International Centre for Materials Science Superstripes (RICMASS) and Gaetano Campi of the Italian Council of National Research (CNR) looked at it with high-energy X-rays at DESYs synchrotron light source DORIS (beamline BW5), the Italian synchrotron Elettra and the European Synchrotron Radiation Source ESRF.

    DESY DORIS
    DORIS

    Elettra Synchrotron Italy
    ElettraESRF
    ESRF

    Here they used a special space resolved diffraction technique (called scanning micro X-ray diffraction) that allows to investigate the microscopic aggregation of electrons in small crystalline domains.

    In conventional materials like metals and semiconductors, the electrons, carriers of the electric charge, move homogenous, like a liquid spreading out evenly in a canal. For many decades scientists believed that superconductivity also had to appear as a homogenous order in the material. By contrast, in the high-temperature cuprate superconductor investigated, the electrons start to aggregate and form puddles at minus 20 degrees Celsius already. „We discovered that the sizes of these puddles vary widely, like the chunks of a molten iceberg or the steam bubbles in a boiling pot“, explains Ricci. While the average puddle measures about 4 nanometres (millionths of a millimetre) across, puddles as large as 40 nanometres could be seen. The distribution of the puddle sizes can be described by a power-law which is typical for self-organisation.

    The scientists could show that the puddles fill the whole material, leaving free interstitial space. Not all electrons become aggregated in these puddles. The electric current, which is carried by pairs of electrons that have remained free, has to flow around the puddles. As the authors found, the interstitial space between the puddles can be described by a special form of geometry: While the world around us usually follows the rules of Euclidean geometry, in the interstitial space of the high-temperature superconductor a hyperbolic geometry applies, as Ricci point out. „These results open new avenues for the design of superconducting materials, and thus could advance the search for a room temperature superconductor.“

    The team consisted of scientists from DESY, RICMASS, CNR, ESRF, Elettra, the University of Twente in The Netherlands, the Queen Mary University of London, the Swiss Federal Institute of Technology, the Moscow State University and Ghent University in Belgium.

    Reference:
    „Inhomogeneity of charge-density-wave order and quenched disorder in a high-Tc superconductor“; G. Campi, A. Bianconi, A. Ricci et al.; Nature, 2015; DOI: 10.1038/nature14987

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    desi

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

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
Follow

Get every new post delivered to your Inbox.

Join 552 other followers

%d bloggers like this: