X-ray science – Page 2 – Lightsources.org

Rotation and axial motion system IV (RAMS IV) load frame

2021/05/172021/06/03

In spring 2021, the fourth generation of Rotation and Axial Motion System (RAMS IV) load frame was commissioned with X-rays at the Structural Materials Beamline (SMB)

WHAT DID THE SCIENTISTS DO?

The main objectives of commissioning were to enable communication between the existing control system of the beamline (SPEC) and the new control system of RAMS IV (Aerotech), and to synchronize triggering of X-ray detectors with positions of the rotation stages on RAMS IV. To this end, a number of new scripts were written and tested for both SPEC and Aerotech for executing commands, exchanging experimental parameters, interlocking and “handshaking” between the two systems. During the last few days of commissioning, a series of X-ray measurements were performed on a sample mounted on RAMS IV to test the main functionalities of the new load frame.

WHAT ARE THE BROADER IMPACTS OF THIS WORK?

The RAMS load frame series collectively form the gold standard for high-impact, precision in-situ X-ray mechanical testing at high-energy synchrotrons. The longstanding collaboration between Air Force Research Laboratory (AFRL) and Pulseray Inc. has delivered a new design and controls system.

Two RAMS IV frames were built: (1) a CHESS design for in-situ X-ray studies, and (2) an AFRL design for ex-situ studies. The AFRL machine can be used for ex-situ proof-of-concept, preparatory loading, or longer mechanical loading tests that can complement and inform work that is done in situ on the CHESS machine.

RAMS IV is optimized for simultaneous tension, torsion, and fatigue loading. Torsion and fatigue loadings are new features over the second generation of RAMS (RAMS II) that has been (and is still being) used with many user experiments at CHESS.

Read more on the CHESS website

Image: Staff Scientists Kelly Nygren and Peter Ko worked in tandem with AFRL to commission the RAMS IV

Game on: Science Edition

2021/03/252021/03/25

After AIs mastered Go and Super Mario, Brookhaven scientists have taught them how to “play” experiments at NSLS-II

Inspired by the mastery of artificial intelligence (AI) over games like Go and Super Mario, scientists at the National Synchrotron Light Source II (NSLS-II) trained an AI agent – an autonomous computational program that observes and acts – how to conduct research experiments at superhuman levels by using the same approach. The Brookhaven team published their findings in the journal Machine Learning: Science and Technology and implemented the AI agent as part of the research capabilities at NSLS-II.

As a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE’s Brookhaven National Laboratory, NSLS-II enables scientific studies by more than 2000 researchers each year, offering access to the facility’s ultrabright x-rays. Scientists from all over the world come to the facility to advance their research in areas such as batteries, microelectronics, and drug development. However, time at NSLS-II’s experimental stations – called beamlines – is hard to get because nearly three times as many researchers would like to use them as any one station can handle in a day—despite the facility’s 24/7 operations.

“Since time at our facility is a precious resource, it is our responsibility to be good stewards of that; this means we need to find ways to use this resource more efficiently so that we can enable more science,” said Daniel Olds, beamline scientist at NSLS-II and corresponding author of the study. “One bottleneck is us, the humans who are measuring the samples. We come up with an initial strategy, but adjust it on the fly during the measurement to ensure everything is running smoothly. But we can’t watch the measurement all the time because we also need to eat, sleep and do more than just run the experiment.”

Read more on the Brookhaven website

Image: NSLS-II scientists, Daniel Olds (left) and Phillip Maffettone (right), are ready to let their AI agent level up the rate of discovery at NSLS-II’s PDF beamline.

Credit: Brookhaven National Lab

Cooking pollution more resilient than previously thought

2020/12/102020/12/17

Following research undertaken at Diamond, particulate emissions from cooking have been discovered to stay in the atmosphere for longer than initially thought, causing a prolonged contribution to poor air quality and human health.

A new study, led by researchers at the University of Birmingham, demonstrated how cooking emissions can survive in the atmosphere over several days, rather than being broken up and dispersed.

The team collaborated with Diamond, the University of Bath and the Central Laser Facility to show how these fatty acid molecules react with molecules found naturally in the earth’s atmosphere. During the reaction process, a coating is formed around the outside of the particle that protects the fatty acid inside from gases such as ozone which would otherwise break up the particles.

This research was made possible by using Diamond’s powerful X-ray beamline (I22). For the first time researchers we able to recreate the reaction process in a way that enables it to be studied in laboratory conditions.

Read more on the Diamond website

Dust travelled thousands of miles to enrich hawaiian soils

2020/11/052020/11/10

With its warm weather and sandy beaches, Hawaii is a magnet for tourists every year. This unique ecosystem also attracts soil scientists interested in what surprises may lie beneath their feet.

In a recent paper published in Geoderma, European researchers outline how they used the rich soils of Hawaii to study the critical movement of phosphorous through the environment. By better understanding the amount and type of phosphorus in the soil, they can help crops become more successful and maintain the health of our ecosystems for years to come.

The project was led by Agroscope scientist Dr. Julian Helfenstein, Prof. Emmanuel Frossard with the Institute of Agricultural Sciences, ETH Zurich; and Dr. Christian Vogel, a researcher at the Federal Institute for Materials Research and Testing in Berlin.

The team used the Canadian Light Source (CLS) at the University of Saskatchewan to help analyze the different types of phosphorus in their samples and track their origins.

Read more on the Canadian Light Source website

Image: Dr. Christian Vogel using the VLS-PGM beamline to analyze a sample at the CLS.

A new approach for studying electric charge arrangements in a superconductor

2020/11/032020/11/03

X-ray scattering yields new information on “charge density waves”

High-temperature superconductors are a class of materials that can conduct electricity with almost zero resistance at temperatures that are relatively high compared to their standard counterparts, which must be chilled to nearly absolute zero—the coldest temperature possible. The high-temperature materials are exciting because they hold the possibility of revolutionizing modern life, such as by facilitating ultra-efficient energy transmission or being used to create cutting-edge quantum computers.

One particular group of high-temperature superconductors, the cuprates, has been studied for 30 years, yet scientists still cannot fully explain how they work: What goes on inside a “typical” cuprate?

Piecing together a complete picture of their electronic behavior is vital to engineering the “holy grail” of cuprates: a versatile, robust material that can superconduct at room temperature and ambient pressure.

Read more on the NSLS-II website

Image: Brookhaven Lab scientist Mark Dean used the Soft Inelastic X-Ray (SIX) beamline at the National Synchrotron Light Source II (NSLS-II) to unveil new insights about a cuperates, a particular group of high-temperature superconductors. Credit: BNL

Get out your vacuum: Scientists find harmful chemicals in household dust

2020/11/022020/11/02

Since the 1970s, chemicals called brominated flame retardants (BFRs) have been added to a host of consumer and household products, ranging from electronics and mattresses to upholstery and carpets. While they were intended to improve fire safety, one form — polybrominated diphenyl ethers, or PBDEs — has proved harmful to human health, specifically our hormonal systems.

Although the use of PBDEs has been restricted in Canada since 2008, older household electronics and furniture with these compounds are still in use. Additionally, the process used to add this chemical to manufactured goods attached the particles very loosely. As a result, the compound tends to shed over time through normal wear and tear.

A growing body of evidence suggests that concentrations of this chemical are higher indoors and that it is present in dust. A team of researchers from the Canadian Light Source (CLS) at the University of Saskatchewan and Memorial University set out to determine whether they could find bromine in household dust using synchrotron X-ray techniques.

Read more on the Canadian Light Source website

Image: Dr. Peter Blanchard, CLS Associate Scientist, standing in the HXMA beamline at the CLS.

Order in the disorder: density fluctuations in amorphous silicon discovered

2020/10/292020/11/01

For the first time, a team at HZB has identified the atomic substructure of amorphous silicon with a resolution of 0.8 nanometres using X-ray and neutron scattering at BESSY II and BER II. Such a-Si:H thin films have been used for decades in solar cells, TFT displays, and detectors. The results show that three different phases form within the amorphous matrix, which dramatically influences the quality and lifetime of the semiconductor layer. The study was selected for the cover of the actual issue of Physical Review Letters.

Silicon does not have to be crystalline, but can also be produced as an amorphous thin film. In such amorphous films, the atomic structure is disordered like in a liquid or glass. If additional hydrogen is incorporated during the production of these thin layers, so-called a-Si:H layers are formed. “Such a-Si:H thin films have been known for decades and are used for various applications, for example as contact layers in world record tandem solar cells made of perovskite and silicon, recently developed by HZB” explains Prof. Klaus Lips from HZB. “With this study, we show that the a-Si:H is by no means a homogeneously amorphous material. The amorphous matrix is interspersed with nanometre-sized areas of varying local density, from cavities to areas of extremely high order,” the physicist comments.

Red and black ink from Egyptian papyri unveil ancient writing practices

2020/10/262020/10/29

Scientists led by the ESRF and the University of Copenhagen have discovered the composition of red and black inks in ancient Egyptian papyri from circa 100-200 AD, leading to different hypotheses about writing practices. The analysis shows that lead was probably used as a dryer rather than as a pigment, similar to its usage in 15th century Europe during the development of oil paintings. They publish their results today in PNAS.

The earliest examples of preserving human thought by applying ink on a flexible and durable material, papyrus, are found in ancient Egypt at the dawn of recorded history (c. 3200 BCE). Egyptians used black ink for writing the main body of text, while red ink was often used to highlight headings, instructions or keywords. During the last decade, many scientific studies have been conducted to elucidate the invention and history of ink in ancient Egypt and in the Mediterranean cultures, for instance ancient Greece and Rome.

Read more on The European Synchrotron website

Image: Detail of a medical treatise (inv. P. Carlsberg 930) from the Tebtunis temple library with headings marked in red ink. Credit: The Papyrus Carlsberg Collection and the ESRF.

Electron and X‑ray Focused Beam-Induced Cross-Linking in Liquids:

2020/10/262020/10/27

Toward Rapid Continuous 3D Nanoprinting and Interfacing using Soft Materials

Modern additive fabrication of three-dimensional (3D) micron to centimeter size constructs made of polymers and soft materials has immensely benefited from the development of photocurable formulations suitable for optical photolithography,holographic,and stereolithographymethods. Recent implementation of multiphoton laser polymerization and its coupling with advanced irradiation schemes has drastically improved the writing rates and resolution, which now approaches the 100 nm range. Alternatively, traditional electron beam lithography and its variations such as electron-beam chemical lithography, etc. rely on tightly focused electron beams and a high interaction cross-section of 0.1−10 keV electrons with the matter and have been routinely used for complex patterning of polymer resists, self-assembled monolayers, and dried gel films with up to a few nanometers accuracy.

Similarly, a significant progress has been made in deep X-ray lithography, direct writing with zone plate focused X-ray beams for precise, and chemically selective fabrication of high aspect ratio microstructures. Reduced radiation damage within the so-called “water window” has spurred wide biomedical X-ray spectroscopy, microscopy, and tomography research including material processing, for example, gels related controlled swelling and polymerization inside live systems, particles encapsulations,and high aspect ratio structures fabrication.The potential of focused X-rays for additive fabrication through the deposition from gas-phase precursors or from liquid solutions is now well recognized and is becoming an active area of research.

Read more on the Elettra website

Image: The electron/X-ray beam gelation in liquid polymer solution through a SiN ultrathin membrane. Varying the energy and focus of the soft X-rays smaller or larger excitation volumes and therefore finer or wider feature sizes and patterns can be generated.

IBM Investigates Microelectronics at NSLS-II

2020/10/262020/11/01

IBM researchers used the Hard X-ray Nanoprobe at NSLS-II to visualize strain in a new architecture for next-generation microelectronics

From smartphones to laptops, the demand for smaller and faster electronics is ever increasing. And as more everyday activities move to virtual formats, making consumer electronics more powerful and widely available is more important than ever.

IBM is one company at the forefront of this movement, researching ways to shrink and redesign their microelectronics—the transistors and other semiconductor devices that make up the small but mighty chips at the heart of all consumer electronics.

“As devices get smaller, it becomes more challenging to maintain electrostatic control,” said Conal Murray, a scientist at IBM’s T.J. Watson Research Center. “To ensure we can deliver the same level of performance in smaller devices, we’ve been employing new semiconductor materials and designs over the last decade.”

Read more on the NSLS-II website

Image: NSLS-II scientist Hanfei Yam is shown at the Hard X-ray Nanoprobe beamline, where IBM researchers visualised strain in a new architecture for next-generation microelectronics.

Producing less costly, greener hydrogen peroxide

2020/10/212020/10/22

Australian researchers led by the University of New South Wales have used the Australian Synchrotron to understand how the chemical structure of an advanced catalytic material contributes to its stability and efficiency. The approach has the potential to produce hydrogen peroxide (H₂O₂) in a process that is cost-effective with less harm to the environment.

Hydrogen peroxide is an important chemical that used widely in a range of applications, including wastewater treatment, disinfection, paper/pulp bleaching, semi-conductor cleaning, mining and metal processing, fuel cells and in chemical synthesis.

According to an international market research group, IMARC, the global hydrogen peroxide market size was valued at US$4.0 billion in 2017 and is increasing.

Read more on the ANSTO website

Image: The optimized geometry structures of bare CoN₄ moiety and CoN₄ moieties with different coverages of epoxy oxygen. The gray, blue, orange and red balls represent C, N, Co and O atoms, respectively [Reprinted with permission by Creative Commons License: Attribution 4.0 International (CC BY 4.0)]

PHELIX beamline is ready to research

2020/10/072020/10/08

Synchrotron light has finally been observed for the first time on a sample at the end station of the experimental beamline PHELIX. This success is the crowning achievement of three years of hard work designing, constructing, fitting, and tuning its components to the synchrotron beam.

The installation of this new beamline began in mid-2018. In March of 2020, the final elements were delivered. Then on 18th September 2020, the scientific supervisors of beamline, Dr. Magdalena Szczepanik – Ciba and Tomasz Sobol, announced readiness for test experiments using the synchrotron beam.

The first results testing the capabilities with the active beam of the analyser at the PHELIX end station were performed using the sample of gold in the presence of a specialist from the SPECS company, Dr. Robert Reichelt. As a result of testing this calibration material, among others, the XPS Au4f spectrum was acquired (see pic.1). Additionally, an angle – resolved and spin – resolved measurements were performed .

During the latest open call for the beamtime the applications on the PHELIX beamline where included for the first time. This line will use soft X-ray radiation. The end-station will enable a wide range of spectroscopic and absorption researches, characterised by different surface sensitivity. Besides acquiring standard, high-resolution spectra, it will allow e.g. for the mapping of band structure in three dimensions and for the detection of spin in three dimensions.

Users will thus be able to conduct research on new materials, thin films, and multi-layer systems, catalysers and biomaterials, as well as research on solids, on spin-polarised surface states, and on chemical reactions taking place on the surface.

Read more on the SOLARIS website

Image: From left Tomasz Sobol, Dr. Robert Reichelt, Dr. Magdalena Szczepanik – Ciba. Credit – Solaris

Who stole the light?

2020/10/072020/10/07

Self-induced ultrafast demagnetization limits the amount of light diffracted from magnetic samples at soft x-ray energies.

Free electron X-ray lasers deliver intense ultrashort pulses of x-rays, which can be used to image nanometer-scale objects in a single shot. When the x-ray wavelength is tuned to an electronic resonance, magnetization patterns can be made visible. However, using increasingly intense pulses, the magnetization image fades away. The mechanism responsible for this loss in resonant magnetic scattering intensity has now been clarified.

A team of researchers from Max Born Institute Berlin (Germany), Helmholtz-Zentrum Berlin (Germany), Elettra Sincrotrone Trieste (Italy) and Sorbonne Université (France), has now precisely recorded the dependence of the resonant magnetic scattering intensity as a function of the x-ray intensity incident per unit area (the “fluence”) on a ferromagnetic domain sample. Via integration of a device to detect the intensity of every single shot hitting the actual sample area, they were able record the scattering intensity over three orders of magnitude in fluence with unprecedented precision, in spite of the intrinsic shot-to-shot variations of the x-ray beam hitting the tiny samples. The experiments with soft x-rays were carried out at the FERMI free-electron x-ray laser in Trieste, Italy.

In the results presented in the journal Physical Review Letters, the researchers show that while the loss in magnetic scattering in resonance with the Co 2p core levels has been attributed to stimulated emission in the past, for scattering in resonance with the shallower Co 3p core levels this process is not significant. The experimental data over the entire fluence range are well described by simply considering the actual demagnetization occurring within each magnetic domain, which the experimental team had previously characterized with laser-based experiments. Given the short lifetime of the Co 3p core, dominated by Auger decay, it is likely that the hot electrons generated by the Auger cascade, in concert with subsequent electron scattering events, lead to a reshuffling of spin up and spin down electrons transiently quenching the magnetization.

Read more on the ELETTRA website

Image: Schematic sketch of the scattering experiment with two competing processes. The soft x-ray beam (blue line) hits the magnetic sample where it scatters from the microscopic, labyrinth-like magnetization pattern. In this process, an x-ray photon is first absorbed by a Co 3p core level (1). The resulting excited state can then relax either spontaneously (2), emitting a photon in a new direction (purple arrow), or by means the interaction with a second photon via stimulated emission (3). In this last case, the photons are emitted in the direction of the incident beam (blue arrow towards right).

Synthetic fibre triumphs steel

2020/10/062020/10/07

Industrial high-strength fibre has been extensively used in daily lives. In addition to the well-known carbon fibre, “aramid fibre” has become the most comprehensive application and the largest production for the high-strength, flame retardant, and corrosion resistant fibre. Thus strong fibre is considered irreplaceable in fields such as national defense, aerospace, automotive, and energy materials. For flourishing market demand, an annual output of aramid fibre is nearly 100K tons in the word. Only several countries, including the US, Japan, Russia, and South Korean, however, are capable of mass production. Among them, the US and Japan occupy 90% market share.

Developing by DuPont company, “Kevlar” is an aramid fibre with currently the world’s leading high-strength fibre. Their strength is 5 times stronger than steel, with merely 1/5 the density of steel. In fact, the light-weight bullet proof clothing is mostly made by Kevlar.

Read more on the National Synchrotron Radiation Research Center website

Image: Customized “mini wet-spinning machine”. Credit NSRRC

Searching for the chemistry of life

2020/10/022020/10/08

Study shows possible new way to create DNA base pairs

In the search for the chemical origins of life, researchers have found a possible alternative path for the emergence of the characteristic DNA pattern: According to the experiments, the characteristic DNA base pairs can form by dry heating, without water or other solvents. The team led by Ivan Halasz from the Ruđer Bošković Institute and Ernest Meštrović from the pharmaceutical company Xellia presents its observations from DESY’s X-ray source PETRA III in the journal Chemical Communications.

“One of the most intriguing questions in the search for the origin of life is how the chemical selection occurred and how the first biomolecules formed,” says Tomislav Stolar from the Ruđer Bošković Institute in Zagreb, the first author on the paper. While living cells control the production of biomolecules with their sophisticated machinery, the first molecular and supramolecular building blocks of life were likely created by pure chemistry and without enzyme catalysis. For their study, the scientists investigated the formation of nucleobase pairs that act as molecular recognition units in the Deoxyribonucleic Acid (DNA).

Read more on the PETRA III (DESY) website

Image: From the mixture of all four nucleobases, A:T pairs emerged at about 100 degrees Celsius and G:C pairs formed at 200 degrees Celsius. Credit: Ruđer Bošković Institute, Ivan Halasz

$A kappa diffractometer for intermediate X-ray energies at APS beamline 29-ID$

A kappa diffractometer for intermediate X-ray energies at APS beamline 29-ID

2020/10/022020/10/07

An ultra-high vacuum, non-magnetic kappa geometry diffractometer has been designed and commissioned for the resonant soft x-ray scattering (RSXS) branch of the X-ray Science Division (XSD) Intermediate Energy X-ray (IEX) beamline 29-ID at the Advanced Photon Source (APS). Beamline 29-ID is managed by the XSD Magnetic Materials Group; the APS is an Office of Science user facility at Argonne National Laboratory. There were three main design goals for this diffractometer: kappa geometry, non-magnetic, and high-precision. The kappa geometry was chosen to allow for a large q-range and space for a sample environment (electric or magnetic fields). Non-magnetic components were used for all the components above and including the κ-arm to avoid disturbing magnetic or electric fields during experiments. Lastly, the diffractometer precision requirement of a sphere of confusion (SOC) of less than 50 µm was a key driving factor for this instrument in terms of rotation stages and machining precision.

The complete diffractometer can be seen in Fig. 1(a), shown installed into the RSXS UHV vacuum chamber at 29-ID. The precise SOC (< 50 µm) requirement drove the design method. In order to reach this goal, it was decided that a combination of precision machining, Finite element analysis, and stage precision would be used instead of calibrating an error-correction table. This has the advantage that the upper bound of the SOC requirement can be achieved without any control hardware, making the device more robust.

Read more on the Advanced Photon Source Website

Image: Fig1. (a) Image of the commissioned kappa diffractometer inside the RSXS vacuum chamber on the APS 29-ID beamline with the main components identified. (b) A close up model of the components above the f axis. The model also shows the new thermal break and thermal strap.