Latest-News – Page 120 – Lightsources.org

Third light source generates first X-ray light

2018/05/032018/05/04

European XFEL starts operation of its third light source, exactly a year after the first X-ray light was generated in the European XFEL tunnels. The third light source will provide light for the MID (Materials Imaging and Dynamics) and HED (High Energy Density Science) instruments scheduled to start user operation in 2019. All three light sources, successfully run in parallel for the first time on the anniversary of European XFEL’s first light, will eventually provide X-rays for at least six instruments. At any one time, three of these six instruments can simultaneously receive X-ray beam for experiments. “The operation of the third light source, and the generation of light from all sources in parallel, are important steps towards our goal of achieving user operation on all six instruments” said European XFEL Managing Director Robert Feidenhans’l. “I congratulate and thank all those involved in this significant accomplishment. It was a tremendous achievement to get all three light sources to generate light within the space of one year.”

To generate flashes of X-ray light, electrons are first accelerated to near the speed of light before they are moved through long rows of magnets called undulators. The alternating magnetic fields of these magnets force the electrons on a slalom course, causing the electrons to emit light at each turn. Over the length of the undulator, the produced light interacts back on the electron bunch, thereby producing a particularly intense light. This light accumulates into intensive X-ray flashes. This process is known as ‘self-amplified spontaneous emission’, or SASE. European XFEL has three SASE light sources. The first one, SASE 1, taken into operation at the beginning of May 2017, provides intense X-ray light to the instruments SPB/SFX (Single Particles, Clusters and Biomolecules and Serial Femtosecond Crystallography) and FXE (Femtosecond X-ray Experiments), the first instruments available for experiments and operational since September 2017. The second light source, SASE 3, was successfully taken into operation in February 2018 and will provide light for the instruments SQS (Small Quantum Systems) and SCS (Spectroscopy and Coherent Scattering), scheduled to start user operation in November 2018. SASE 1 and SASE 3 can be run simultaneously – high speed electrons first generate X-ray light in SASE 1, before being used a second time to produce X-ray light of a longer wavelength in SASE 3. Now, exactly a year after the first laser light was generated in the European XFEL tunnels, the third light source, SASE 2, is operational. SASE 2 will generate X-ray light for the MID (Materials Imaging and Dynamics) and HED (High Energy Density Science) instruments scheduled to start user operation in 2019. The MID instrument will be used to, for example, understand how glass forms on an atomic level, and for the study of cells and viruses with a range of imaging techniques. The HED instrument will enable the investigation of matter under extreme conditions such as that inside exoplanets, and to investigate how solids react in high magnetic fields.

>Read more on the European XFEL website and the article on the DESY website.

Image: All three light sources, SASE 1,2 and 3, are now operational and have been successfully run in parallel for the first time.
Credit: DESY/European XFEL

Freeze-framing nanosecond movements of nanoparticles

2018/05/032018/05/03

New method allows to monitor fast movements at hard X-ray lasers.

A team of scientists from DESY, the Advanced Photon Source APS and National Accelerator Laboratory SLAC, both in the USA, have developed and integrated a new method for monitoring ultrafast movements of nanoscopic systems. With the light of the X-ray laser LCLS at the research center SLAC in California, they took images of the movements of nanoparticles taking only the billionth of a second (0,000 000 001 s). In their experiments now published in the journal Nature Communications they overcame the slowness of present-day two-dimensional X-ray detectors by splitting individual laser flashes of LCLS, delaying one half of it by a nanosecond and recording a single picture of the nanoparticle with these pairs of X-ray pulses. The tunable light splitter for hard X-rays which the scientists developed for these experiments enables this new technique to monitor movements of nanometer size fluctuations down to femtoseconds and at atomic resolution. For comparison: modern synchrotron radiation light sources like PETRA III at DESY can typically measure movements on millisecond timescales.

The intense light flashes of X-ray lasers are coherent which means that the waves of the monochromatic laser light propagate in phase to each other. Diffracting coherent light by a sample usually results in a so-called speckle diffraction pattern showing apparently randomly ordered light spots. However, this speckle is also a map of the sample arrangement, and movements of the sample constituents result in a different speckle pattern.

>Read more on the DESY website

Image: Scheme of the experiment: An autocorrelator developed at DESY splits the ultrashort X-ray laser pulses into two equal intensity pulses which arrive with a tunable delay at the sample. The speckle pattern of the sample is collected in a single exposure of the 2-D detector
Credit: W. Roseker/DESY

One size does not fit all when exploring how carbon in soil affects the climate

2018/05/032018/05/18

Scientists from Stanford University are opening a window into soil organic carbon, a critical component of the global carbon cycle and climate change.

“We have to know what kind of carbon is in soil in order to understand where the carbon comes from and where it will go,” said Hsiao-Tieh Hsu, a PhD student in chemistry at Stanford University and a member of a Kate Maher’s research group.

The natural fluxes of soil organic carbon, the exchange of carbon moving from vegetation to the soil and recycled by microorganisms before being stabilized in the soil or returned to the atmosphere, is 10 to 20 times higher than human emissions. Even the smallest change in the flux of soil organic carbon would have a huge impact on the climate.

Soil organic carbon occurs naturally and is part of the carbon cycle. Through photosynthesis, plants absorb carbon dioxide from the atmosphere. As plants and their roots decompose, they deposit organic carbon in the soil. Microorganisms, decomposing animals, animal feces and minerals also contribute to the organic carbon in the soil. In turn, plants and microorganisms “eat” that carbon, which is an essential nutrient.

All of this results in different “flavours” or compounds within the soil, say Hsu and Maher, who is also a faculty member of the Stanford Center for Carbon Storage.

Image: Members of the research team at the East River, Colorado, field site (left to right): Hsiao-Tieh Hsu; Grace Rainaldi, Stanford undergraduate; Corey Lawrence, research geologist at United States Geological Survey; Kate Maher; Matthew Winnick, Stanford postdoctoral fellow.
Credit: Kate Maher.

Scientists find a new way to make novel materials by ‘un-squeezing’

2018/05/012018/05/02

Like turning a snowball back into fluffy snow, a new technique turns high-density materials into a lower-density one by applying the chemical equivalent of ‘negative pressure.’

Some materials can morph into multiple crystal structures with very different properties. For instance, squeezing a soft form of carbon produces diamond, a harder and more brilliant form of carbon. The Kurt Vonnegut novel “Cat’s Cradle” featured ice-nine, a fictional form of water with a much higher melting point than regular ice that threatened to irreversibly freeze all the water on Earth.

These materials are called polymorphs, and they’re commonly made by applying pressure, or squeezing. Scientists looking for new materials would also like to do the opposite – apply “negative pressure” to stretch a material’s crystal structure into a new configuration. In the past, this approach seemed to require negative pressures that are difficult if not impossible to achieve in the lab, plus it risked pulling the material apart.

Now researchers at the Department of Energy’s National Renewable Energy Laboratory (NREL) have found a way to create the equivalent of negative pressure by mixing two materials together under just the right conditions to make an alloy with an airier and entirely different crystal structure and unique properties.

>Read more on the SSRL website

Image: SLAC staff scientists Laura Schelhas and Kevin Stone at an experimental station at the Stanford Synchrotron Radiation Lightsource, where they used X-rays to measure the structure of a novel ‘negative pressure’ material created at NREL.
Credit: Matt Beardsley/SLAC National Accelerator Laboratory

SESAME light source brings second beamline into service

2018/05/012018/05/03

Allan, Jordan, 30 April 2018. At 11:21 pm local time (GMT +3) scientists at the SESAME light source brought the laboratory’s infrared (IR) spectromicroscopy beamline into service for the first time.

This beamline is a completely new beamline. It was designed and built in collaboration with the French Soleil Synchrotron. It is SESAME’s second operational beamline, and it joins an X-ray beamline that saw first light on 23 November 2017. The addition of the IR beamline will enable the application of infrared microspectroscopy and imaging in a wide range of fields, including surface and materials science (e.g. characterization of new nanomaterials for solar cell fabrication and for drug delivery mechanisms), biochemistry, archaeology, geology, cell biology, biomedical diagnostics and environmental science (e.g. air and water pollution)

“I’ve been waiting a long time for this moment,” said Gihan Kamel, SESAME’s IR beamline scientist. “It’s very satisfying to see light in the beamline, and to be able to start doing research here that we previously had to travel to Europe to carry out.”

In preparation for the SESAME research programme, a number of thematic schools are being held across the region in a collaboration involving SESAME and European partners including the European Union through its Open SESAME project. One of these was held at SESAME earlier this month, covering science on the IR beamline. Students came from across the region and learned techniques ranging from sample preparation to data analysis.

“The infrared beamline has a mouth-watering research programme lined up,” said SESAME Scientific Director Giorgio Paolucci, “and it is great to see so many young people from across the region preparing to embark on careers in science.”

>Read more on the SESAME website

Putting CO2 to a good use

2018/04/302018/05/02

One of the biggest culprits of climate change is an overabundance of carbon dioxide in the atmosphere.

As the world tries to find solutions to reverse the problem, scientists from Swansea University have found a way of using CO2 to create ethylene, a key chemical precursor. They have used ID03 to test their hypotheses.

Carbon dioxide is essential for the survival of animals and plants. However, people are the biggest producers of CO₂ emissions. The extensive use of fossil fuels such as coal, oil, or natural gas has created an excess of CO₂ in the atmosphere, leading to global warming. Considerable research focuses on capturing and storing harmful carbon dioxide emissions. But an alternative to expensive long-term storage is to use the captured CO₂ as a resource to make useful materials.

New class of single atoms catalysts for carbon nanotubes

2018/04/302018/05/02

They exhibit outstanding electrochemical reduction of CO2 to CO.

Experiments using X-rays on two beamlines at the Australian Synchrotron have helped characterise a new class of single atom catalysts (SACs) supported on carbon nanotubes that exhibit outstanding electrochemical reduction of CO2 to CO. A weight loading of 20 wt% for the new class, nickel single atom nitrogen doped carbon nanotubes (NiSA-N-CNTs), is believed to be the highest metal loading for SACs reported to date.

Single atoms of nickel, cobalt and iron were supported on nitrogen doped carbon nanotubes via a one-pot pyrolysis method and compared in the study.

A large international collaboration, led by Prof San Ping Jiang, Deputy Director of the Fuels and Energy Technology Institute at the Curtin University of Technology and associates from the Department of Chemical Engineering, have developed a new synthesis and development process for nitrogen-doped carbon nanotubes with a nickel ligand that demonstrate high catalytic activity.

The study was published in Advanced Materials and featured on the inside cover of the publication.

Dr Bernt Johannessen, instrument scientist on the X-ray absorption spectroscopy (XAS) beamline at the Australian Synchrotron was a co-author on the paper, which also included lead investigators from Curtin University of Technology and collaborators at the University of Western Australia, Institute of Metal Research (China), Oak Ridge National Laboratory (US), University of the Sunshine Coast, University of Queensland, Tsinghua University (China) and King Abdulaziz University (Saudi Arabia). Technical support and advice on the soft X-ray spectroscopy experiments was provided by Australian Synchrotron instrument scientist Dr Bruce Cowie.

Image: extract of the cover of Advanced Materials.

A new Polarisation Analyser, and the benefits of 3D printing

2018/04/282018/05/02

The I16 beamline at Diamond is dedicated to the study of advanced materials using X-ray diffraction; part of this process is to use a device, known as a polarisation analyser (PA) that can analyse magnetic scattering from samples. Magnetic scattering is different to, and weaker than, normal X-ray scattering and analysis of the polarisation of this scattering can be used to gain insights into the magnetic properties of materials. Researchers can use this information to determine details of the 3D structure of the sample material.

The design of the PA includes an assembly of vacuum chambers, sets of slits to remove unwanted scattering and various detectors, arranged to rotate about different axes. Researchers use data collected from the detectors as they are moved and rotated to build up information on the polarisation of the scattering.

Image: extract of the polarisation analyser; to watch the video “The motion of the main axes of the polarisation analyser”, please have a look here.

Fighting malaria with X-rays

2018/04/252018/04/25

Today 25 April, is World Malaria Day.

Considered as one of humanity’s oldest life-threatening diseases, nearly half the world population is at risk, with 216 million people affected in 91 countries worldwide in 2016. Malaria causes 445 000 deaths every year, mainly among children. The ESRF has been involved in research into Malaria since 2005, with different techniques being used in the quest to find ways to prevent or cure the disease.

Malaria in humans is caused by Plasmodium parasites, the greatest threat coming from two species: P. falciparum and P. vivax. The parasites are introduced through the bites of infected female Anopheles mosquitoes. They travel to the liver where they multiply, producing thousands of new parasites. These enter the blood stream and invade red blood cells, where they feed on hemoglobin (Hgb) in order to grow and multiply. After creating up to 20 new parasites, the red blood cells burst, releasing daughter parasites ready for new invasions. This life cycle leads to an exponential growth of infected red blood cells that may cause the death of the human host.

The research carried out over the years at the ESRF has aimed to identify mechanisms critical for the parasite’s survival in the hope of providing an intelligent basis for the development of drugs to stop the parasite’s multiplication and spread.

>Read more on the European Synchrotron website

Image: Inside the experimental hutch of the ESRF’s ID16A nano-analysis beamlin.
Credit: Pierre Jayet

Scientists explore how slow release fertilizer behaves in soil

2018/04/252018/04/26

Testing soil samples at the Canadian Light Source has helped a University of Saskatchewan soil scientist understand how tripolyphosphate (TPP), a slow release form of phosphorus fertilizer, works in the soil as a plant nutrient for much longer periods than previously thought.

Jordan Hamilton says the research also has implications for ongoing efforts by U of S soil scientists to use phosphorous-rich materials to clean up contaminated petroleum sites.

Hamilton, now a post-doctoral fellow working within U of S professor Derek Peak’s Environmental Soil Chemistry group, had a chapter of his PhD thesis, “Chemical speciation and fate of tripolyphosphate after application to a calcareous soil,” published earlier this year in the online journal Geochemical Transactions.

TPP needs to break down into a simpler form of phosphate in order to be used as a nutrient by plants. In most types of soil, the belief was that TPP would break down right away, says Hamilton.

“I would definitely say the biggest surprise is how quickly the TPP adsorbed (attached itself) to mineral sources, especially in these calcium-rich soils,” he said. “For the longer term, it was surprising to see it persist.”

Garnet gemstones contain secrets of our seismic past

2018/04/232018/04/23

Somewhere in the world an earthquake is occurring. In general, it will be a small tremor, an earthquake of magnitude two or lower, which humans cannot even feel. However when a major earthquake occurs, of magnitude 7 or above, it can cause devastating damage, events like tsunamis, and loss of life. These type of quakes, like the 2011 event in Japan and 2015 Nepalese events, happen around 20 times each year worldwide.

Large earthquakes tend to occur in subduction zones, such as the so-called Ring of Fire, where tectonic plates meet and one is bent and forced underneath the other, into the mantle of the earth. As well as leading to earthquakes, subduction also causes the composition and structure of the rock itself to become altered, in a process called high-pressure/low temperature metamorphism.

Metamorphism can take a variety of forms, in a number of different rocks, but one that is of particular interest is a type called rhythmic major-element zoning, in the mineral garnet. If found it can be a sign that subduction has occurred, and it can act as a record of seismicity in the crust of our Earth.

Support for HZB’s future and call for rapid planning of Bessy III

2018/04/192018/04/19

The Helmholtz-Zentrum Berlin (HZB) has received an evaluation of “excellent” in a review of science programmes undertaken at all Helmholtz Research Centres.

This provides the foundation for future financing of HZB.
Two committees of leading international scientists visited the HZB for a week each at the beginning of this year. They evaluated the HZB’s contributions to the Helmholtz programmes in the research areas of “Matter” and “Energy”. Now the written evaluations are available. The team spirit of all employees involved in the HZB was particularly emphasised.

The report states that the HZB and the Helmholtz Association have made decisions characterised by vision. The right course had been set both in terms of infrastructure and in recruiting people. The HZB can rely on highly competent, committed employees at all levels.

All research programmes of the HZB have received an evaluation of “excellent”. The HZB contributions to the MML programme (From Matter to Materials and Life) focussing on the use of photons are considered to be leading, with all of its participating groups receiving the top marks of “Outstanding” or “Excellent”. The Renewable Energies (RE) and the Future Information Technologies (FIT) programmes, the instrumentation at the BESSY II synchrotron (some of which is unique), and the BER II research reactor were likewise evaluated highly.

Image: The review panel of the research field “Matter” visited the HZB on 11th January 2018.
Credit: HZB/J. Bierbaum

Monovalent Manganese for High-Performance Batteries

2018/04/192018/04/30

The discovery enables the design of a high-performance, low-cost battery that, according to its developers, outperforms Department of Energy goals on cost and cycle life for grid-scale energy storage.

The widespread deployment of renewable energy sources such as solar and wind power destabilizes the electric grid because conventional power-generation systems cannot ramp quickly enough to balance the power variations from these intermittent sources. Storing energy in batteries could help to even things out, but the cost of most existing technologies—including lithium-ion batteries—is significant, hindering grid-scale applications.

Emerging storage technologies such as aqueous sodium (Na) systems offer low costs for long-duration storage, but they do not have the charge/discharge rates needed to balance volatile power generation. In particular, it remains a critical challenge to develop a stable negative electrode (anode) for high-rate Na-ion battery systems.

A battery breakthrough

Compared with the relatively mature designs of anodes used in Li-ion batteries, anodes for Na-ion batteries remain an active focus of research and development. Natron Energy (formerly Alveo Energy), a battery-technology company based in Santa Clara, California, developed an unconventional anode design using a blend of elements chemically similar to the paint pigment known as Prussian blue.

Image: Atomic structure of an electrode material, manganese hexacyanomanganate (MnHCMn), that achieved high performance in a sodium-ion battery. The open framework contains large interstices and channels that allow sodium (Na) ions to move in and out with near-zero strain. Manganese (Mn) ions form the corners of the cage: Mn(N) has six nitrogen nearest neighbors and Mn(C) has six carbon nearest neighbors.

Writing and deleting magnets with lasers

2018/04/182018/04/19

**Scientists * have found a way to write and delete magnets in an alloy using a laser beam – a surprising effect.**

* at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia in Charlottesville, USA

The reversibility of the process opens up new possibilities in the fields of material processing, optical technology, and data storage.
Researchers of the HZDR, an independent German research laboratory, studied an alloy of iron and aluminum. It is interesting as a prototype material because subtle changes to its atomic arrangement can completely transform its magnetic behavior. “The alloy possesses a highly ordered structure, with layers of iron atoms that are separated by aluminum atomic layers. When a laser beam destroys this order, the iron atoms are brought closer together and begin to behave like magnets,” says HZDR physicist Rantej Bali.

Bali and his team prepared a thin film of the alloy on top of transparent magnesia through which a laser beam was shone on the film. When they, together with researchers of the HZB, directed a well-focused laser beam with a pulse of 100 femtoseconds (a femtosecond is a millionth of a billionth of a second) at the alloy, a ferromagnetic area was formed. Shooting laser pulses at the same area again – this time at reduced laser intensity – was then used to delete the magnet.

Image: Laser light for writing and erasing information – a strong laser pulse disrupts the arrangement of atoms in an alloy and creates magnetic structures (left). A second, weaker, laser pulse allows the atoms to return to their original lattice sites (right). (Find the entire image here)
Credit: Sander Münster / HZDR

Insights into the development of more effective anti-tumour drug

2018/04/182018/04/23

Natural killer cells are powerful weapons our body’s immune systems count on to fight infection and combat diseases like cancer, multiple sclerosis, and lupus. Finding ways to spark these potent cells into action could lead to more effective cancer treatments and vaccines.

While several chemical compounds have shown promise stimulating a type of natural killer cells, invariant natural killer T cells (iNKT) cells in animal models, their ability to activate human iNKT cells has been limited.

Now, an international team of top immunologists, structural biologists, and chemists published in Cell Chemical Biology the creation of a new compound that appears to have the properties researchers have been looking for. The research was co-led by Monash Biomedicine Discovery Institute’s (BDI) Dr Jérôme Le Nours, University of Connecticut’s Professor Amy Howell and Albert Einstein College of Medicine’s Dr Steve Porcelli. Dr Le Nours used the Micro Crystallography beamline (MX2) at the Australian Synchrotron as part of the study.

The compound – a modified version of an earlier synthesized ligand – is highly effective in activating human iNKT cells. It is also selective – encouraging iNKT cells to release a specific set of proteins known as Th1 cytokines, which stimulate anti-tumour immunity.

Image: 3D structure of proteins behind interaction of new drug that stimulates immune response to cancer cells. (Entire image here)

Toward control of spin states for molecular electronics

2018/04/172018/04/19

The results represent a major step toward the goal of programmable, nanoscale molecular electronics for high-speed, low-power, logic and memory applications.

To squeeze more information into smaller spaces, we will need to downsize from microchips to the nanoscale: the molecular level. Compared to bulk silicon, organic molecules have many advantages when used as building blocks for memory and logic components. They can be implemented as flexible thin films, they can be easily printed, and their potential switching speed is high, while their power requirements are low. But the field of molecular spintronics is still very young, and before its promise can be realized, scientists need a fuller understanding of the fundamental physics in play.

A molecule with crossover appeal

In the molecule studied here—[Fe{H₂B(pz)₂}₂(bipy)]—the spin state is determined by the configuration of the central metal’s outer electrons (i.e., the Fe d-orbital electrons). The presence of the surrounding organic ligands splits the Fe d orbitals. If the splitting is large, the electrons will pair up in the lower orbitals (a low-spin state). If the splitting is small, the electrons can spread out over both levels (a high-spin state). For some classes of molecules, transitions from low- to high-spin states (and vice versa) can be triggered. This “spin crossover” phenomenon is a promising functionality that may be suitable for application in molecular spintronic devices.

>Read more on the ALS website

Image: The molecule studied in this work is a metal–organic coordination complex, i.e., a molecule with a transition metal (iron) at the center, surrounded by organic compounds (“ligands”). The molecular formula is [Fe{H₂B(pz)₂}₂(bipy)], where pz = pyrazol-1-yl and bipy = 2,2′-bipyridine. This picture shows a ball-and-stick model (see more here)