#SynchroLightAt75 campaign launches on International Day of Light

The SRS at Daresbury Laboratory in the UK was the world’s first dedicated synchrotron light source facility. It opened in 1980 and delivered worldwide impact and two Nobel Prizes.

The first of its kind, the SRS enabled research that has improved the quality of our lives in so many ways. This included research into diseases such as HIV and AIDS, as well as motor neurone disease, to name just a few examples. The structure of the Foot & Mouth virus was solved for the first time at the SRS – it was the first animal virus structure to be determined in Europe and led to the development of a vaccine. The huge magnetic memory of the Apple iPod was also the result of research carried out on the SRS. However, its most famous achievement was the key role it played towards a share of two Nobel Prizes in Chemistry.  One to Sir John Walker in 1997, for solving a structure of an enzyme that opened the way for new insights into metabolic diseases, and the other to Sir Venki Ramakrishnan in 2009, for his work on the structure and function of the Ribosome, the particle responsible for protein synthesis in living cells.

During its lifetime, the SRS created a critical mass of highly skilled engineers and technicians at Daresbury Laboratory, with specialisms ranging from detectors to magnets and electronics, and by the time it closed in 2008, it had collaborated with almost every country active in scientific research. It had hosted over 11,000 users from academia, government laboratories and industry worldwide, leading to the publication of more than 5000 research papers, resulting in numerous patents. The economic impact of this was vast on a worldwide scale, but it also played an important role in boosting the regional economy of the North West, having worked with hundreds of local businesses.

The success of the SRS led to the development of many similar machines around the world, with the technologies and skills developed still in use at many facilities today, including its UK successor, the Diamond Light Source at Harwell Science and Innovation Campus in Oxfordshire. It also led to the establishment of ASTeC, a leading centre for accelerator science and technology at Daresbury Laboratory, and the Cockcroft Institute, a joint venture between STFC and the Universities of Lancaster, Liverpool, Manchester and Strathclyde. It is also home to CLARA, a unique particle accelerator designed to develop, test and advance accelerator technologies of the future. Research carried out by accelerator scientists at Daresbury has had many impacts, particularly in the health and medicine arena, including work to develop our next generation of proton imaging technology for cancer detection, and research that could one day lead to more efficient diagnoses of cervical, oesophageal, and prostate cancers. In the footsteps of  senior scientist, Professor Ian Munro, who was responsible for the plan to build the SRS and for its operation at Daresbury, ASTeC’s accelerator scientists and engineers continue to play a key role in designing, building and upgrading the world’s newest generations of accelerator facilities.

Read more on the STFC/UKRI website

Image: The SRS control room


Credit: STFC

Ramon Pascual’s #My1stLight on International Day of Light!

Memory of synchrotron light

The first time I learnt about synchrotron light was around 1968 at a seminar by Manuel Cardona at the University of Madrid about an experiment he developed at DESY. As a particle physicist theoretician, at that time I did not had any idea that many years later I would be involved in a synchrotron light source as ALBA.

At the beginning of the ‘90s, with the idea of constructing a particle accelerator in Spain I realized the interest and the importance of a third-generation light source and I proposed to the Catalan Government the construction of a light source in Spain. After a bit more of a decade of efforts of several people, ALBA was finally approved and their beam lines have been operating for users since 2012.

The success of these ten years of reliable operation is that, ALBA is now preparing its upgrade to a fourth-generation source, ALBA II.

Ramon Pascual

Honorary president of ALBA

Find out more about ALBA here

Image: Aerial view of ALBA

Credit: ALBA

Scientists synthesise new materials at terapascal pressures for the first time

A team led by the University of Bayreuth (Germany) has synthesized, for the first time, new materials at terapascal pressures, using the ESRF’s ID11 and a unique diamond anvil cell. The results are published in the journal Nature.

Matter changes with variations of pressure and temperature, which allows the tuning of many material properties. These possibilities can shed light onto scientific questions, such as the fundamental understanding of the Universe or lead to targeted design of advanced materials. For example, today super-abrasive cubic Boron Nitride is used for grinding high-quality tool steels and artificial diamonds created using high temperature and high pressure are more prevalent than natural ones.

A team of scientists led by the University of Bayreuth has synthesized new materials at terapascal pressures using laser heating for the first time. The team used rhenium-nitrogen compounds as models to show that studies at pressures three times higher than pressure in the center of the Earth are now possible. Natalia Dubrovinskaya, professor at the University of Bayreuth and one of the corresponding authors of the paper, explains the relevance of these compounds:  “These novel rhenium-nitrogen compounds showed that at ultra-high pressures we can make materials that cannot be made at lower pressures/temperatures, and uncover fundamental rules of physics and chemistry. We found, for example, that due to a huge compression, rhenium behaves chemically in a similar way to iron”.

Read more on the ESRF website

Image: Schematic illustration of the Diamond Anvil Cell assembly

Credit: Timofey Fedotenko

Efficient production technique for a novel ‘green’ fertiliser

Advanced milling technique produces slow-release soil nutrient crystals

A purely mechanical method can produce a novel, more sustainable fertiliser in a less polluting way. That is the result of a method optimised at DESY’s light source PETRA III. An international team used PETRA III to optimise the production method that is an adaptation of an ancient technique: by milling two common ingredients, urea and gypsum, the scientists produce a new solid compound that slowly releases two chemical elements critical to soil fertilisation, nitrogen, and calcium. The milling method is rapid, efficient, and clean—as is the fertiliser product, which has the potential to reduce the nitrogen pollution that fouls water systems and contributes to climate change. The scientists also found that their process is scalable; therefore, it could be potentially implemented industrially. The results by scientists from DESY; the Ruđer Bošković Institute (IRB) in Zagreb, Croatia; and Lehigh University in the USA have been published in the journal Green Chemistry. The new fertiliser still needs to be tested in the field.

For several years, scientists from DESY and IRB, have been collaborating to explore the fundamentals of mechanical methods for initiating chemical reactions. This method of processing, called mechanochemistry, uses various mechanical inputs, such as compressing, vibrating, or, in this case, milling, to achieve the chemical transformation. “Mechanochemistry is quite an old technique,” says Martin Etter, beamline scientist at the P02.1 beamline at PETRA III. “For thousands of years, we’ve been milling things, for example, grain for bread. It’s only now that we’re starting to look at these mechanochemical processes more intensively using X-rays and seeing how we can use those processes to initiate chemical reactions.”

Etter’s beamline is one of the few in the world where mechanochemistry can be routinely performed and analysed using X-rays from a synchrotron. Etter has spent years developing the beamline and working with users to fine-tune methods for analysing and optimising mechanochemical reactions. The result has been a globally renowned experiment setup that has been used in studying many types of reactions important to materials science, industrial catalysis, and green chemistry.

Read more on the DESY website

Image: The co-crystals of the novel fertiliser (symbolised here with gypsum) release their nutrients much more slowly

Credit: DESY, Gesine Born

 

Superconducting X-ray laser reaches operating temperature colder than outer space

The facility, LCLS-II, will soon sharpen our view of how nature works on ultrasmall, ultrafast scales, impacting everything from quantum devices to clean energy.

Nestled 30 feet underground in Menlo Park, California, a half-mile-long stretch of tunnel is now colder than most of the universe. It houses a new superconducting particle accelerator, part of an upgrade project to the Linac Coherent Light Source (LCLS) X-ray free-electron laser at the Department of Energy’s SLAC National Accelerator Laboratory.

Crews have successfully cooled the accelerator to minus 456 degrees Fahrenheit – or 2 kelvins – a temperature at which it becomes superconducting and can boost electrons to high energies with nearly zero energy lost in the process. It is one of the last milestones before LCLS-II will produce X-ray pulses that are 10,000 times brighter, on average, than those of LCLS and that arrive up to a million times per second – a world record for today’s most powerful X-ray light sources.

“In just a few hours, LCLS-II will produce more X-ray pulses than the current laser has generated in its entire lifetime,” says Mike Dunne, director of LCLS. “Data that once might have taken months to collect could be produced in minutes. It will take X-ray science to the next level, paving the way for a whole new range of studies and advancing our ability to develop revolutionary technologies to address some of the most profound challenges facing our society.”

With these new capabilities, scientists can examine the details of complex materials with unprecedented resolution to drive new forms of computing and communications; reveal rare and fleeting chemical events to teach us how to create more sustainable industries and clean energy technologies; study how biological molecules carry out life’s functions to develop new types of pharmaceuticals; and peek into the bizarre world of quantum mechanics by directly measuring the motions of individual atoms.

A chilling feat

LCLS, the world’s first hard X-ray free-electron laser (XFEL), produced its first light in April 2009, generating X-ray pulses a billion times brighter than anything that had come before. It accelerates electrons through a copper pipe at room temperature, which limits its rate to 120 X-ray pulses per second.

Read more on the SLAC website

New SwissFEL soft X-ray endstation welcomes first users

Maloja is go. On Wednesday, 23rd March 2022, first user experiments began at the Maloja endstation, which enables explorations into atomic, molecular and optical physics and chemical dynamics. These user experiments mark a double first, not only for Maloja but also for the second, soft X-ray beamline of the SwissFEL, Athos.

Following two years of tireless development, Maloja is beginning to yield its scientific fruits. Developed in parallel with soft X-ray beamline Athos, Maloja is the first endstation to be up and running, and takes advantage of advanced beam parameters, namely, very short pulses, two colour pulses and pump-probe experiments. A key feature of the Maloja endstation is its modular nature, enabling straightforward exchange of chambers and tailoring to individual experimental requirements.

“Because of its flexible design, a wide variety of investigations are possible at Maloja, such as time-resolved measurements of electronic structure changes, non-linear X-ray spectroscopy or research into gas-phase atoms or nanoparticles. I’m really excited to see the diverse science that future users will turn up with,” enthuses Kirsten Schnorr, lead scientist at the Maloja endstation.

Work began on the Maloja project in 2019, with the COVID pandemic striking a few months after first hardware deliveries. With staff working night shifts to create ‘time-dimensional social distancing’, in June 2020 first light entered the Maloja endstation. This heralded the beginning of commissioning experiments and a very close collaboration between the Maloja team and accelerator groups as, step-by-step, the teams developed not only the Maloja endstation, but also a whole new branch of the SwissFEL: Athos.

Read more on the PSI website

Image: Members of Nanostructures and Ultrafast X-ray Science Group, including Daniela Rupp and Mario Sauppe (3rd and 4th from L) together with the Maloja team and Christoph Bostedt (far R) during the beamtime

Credit: Alessandro Colombo

Piero Pianetta’s #My1stLight

First light from the SPEAR Ring at SLAC July 6, 1973
Ingolf Lindau & Piero Pianetta

#My1stLight memory submitted by Piero Piantetta, Deputy Director of SSRC at SLAC


Pilot project to extract synchrotron radiation from the SPEAR ring at SLAC. In-alcove video camera imaging light emitted from a fluorescent screen just downstream of the Be exit window. No beam steering beyond global steering for colliding beam operation. Our group, including Gerry Fisher, waiting to see if beam would even make it through all the apertures. SUCCESS on first opening of line!!!!!

Lightsources.org virtual symposium recording

Lightsources.org was delighted to welcome over 500 attendees to our live virtual symposium to mark the 75th Anniversary of the first direct observation of synchrotron light in a laboratory. The event, which was chaired by Sandra Ribeiro, Chair of lightsources.org and Communications Advisor for the Canadian Light Source, was held on the 28th April 2022 and you can watch the recording via the YouTube link below.

We received some lovely feedback after the live event, including this comment from Jeffrey T Collins at the Advanced Photon Source, Argonne National Laboratory in Illinois.

 “I have worked at the Advanced Photon Source for over 32 years and I learned many things during this event that I never knew before.  It was quite informative.  I look forward to re-watching the entire event.”

Jeffrey T Collins, Mechanical Engineering & Design Group Leader at Argonne National Laboratory

The symposium began with a historical introduction from Roland Pease, freelance science broadcaster who has been an enthusiastic support of light sources for many years.

Roland’s talk was followed by experts from the field giving talks on their perspectives of synchrotron light related achievements that have been made since the 1st laboratory observation on the 24th April 1947.

Speakers were:

• Nobel Laureate Prof. Ada Yonath (Weizmann Institute of Science)

• Prof. Sir Richard Catlow (University College London)

• Prof. Henry Chapman (DESY)

• Dr Paul Tafforeau (ESRF)

• Dr Gihan Kamel (SESAME and member of the AfLS Executive Committee).

There followed a panel discussion with special guests who all made huge contributions to the development of the field. Our special guests were:

Herman Winick – Prof. of Applied Physics (Research) Emeritus at SLAC)

Ian Munro – Initiator of synchrotron radiation research at Daresbury Laboratory ,Warrington UK in 1970

Giorgio Margaritondo – one of the pioneers in the use of synchrotron radiation and free electron lasers

Gerd Materlik – former CEO of Diamond Light Source, the UK’s synchrotron science facility

Lightsources.org is hugely grateful to all the speakers, special guests and attendees who contributed to this event and made it such a special anniversary celebration for the light source community.

If you have any feedback or memories to share, please do contact Silvana Westbury, Project Manager, at webmaster@lightsources.org

For news, jobs, events and proposal deadlines, please visit the homepage

Synchrotron light proves effectiveness of several drugs in virus infections like SARS-CoV2

Microtubules are intracellular structures that function as true cellular highways for the transport of substances, vesicles, organelles and even viruses, in the case that a cell gets infected. In most viral infections, they are the transport routes to generate the viral factories, regions close to the nucleus where virus production is concentrated.

The idea is to design drugs that, by binding to microtubules, prevent viruses from using them during the infection process. In general, drugs that target microtubules are called MTAs (microtubule targeting agents). There are two types: stabilizers (MSA) and destabilizers (MDA). Both are widely available and most of these drugs are in the WHO Essential Medicines List, and hence, they are therapeutic alternatives that are affordable and available worldwide.

Researchers from CIB Margarita Salas selected 16 commercially available MTA (including 15 in clinical use) to analyse their capacity to inhibit the viral replication against 5 different virus: the human common cold coronavirus (HCoV), the pandemic SARS-CoV-2 coronavirus, the vesicular stomatitis virus, the poxvirus vaccinia and African swine fever virus.

Scientist confirmed that the MTA tested had an effect on virus replication and spreading and that this effect varies according to the virus dependency on the microtubular network. “The inhibitory effect obtained varied depending on the specific functions that viruses have developed throughout evolution to exploit cellular transport machinery”, explains Dra. Marian Oliva, researcher at CIB Margarita Salas-CSIC.

In particular, the most complex use of microtubules filaments might correspond to coronavirus (CoVs), such as the one responsible for the Covid-19 pandemic. Microtubules are necessary both for virus internalization and later at several levels of the formation of the viral replication site. In fact, S and M coronavirus proteins (located on the virus surface) interact with tubulin (protein that forms microtubules) during the infection, although their specific function is currently unknown. Various projects involving the use of the ALBA Synchrotron are under way to study deeper these aspects.

Read more on the ALBA website

Image: Image obtained at the XALOC beamline of ALBA. Drug mebendazole (MBZ) bounds to the protein that forms the microtubules: tubulin (T2RT and T1D).

How a soil microbe could rev up artificial photosynthesis

Researchers discover that a spot of molecular glue and a timely twist help a bacterial enzyme convert carbon dioxide into carbon compounds 20 times faster than plant enzymes do during photosynthesis. The results stand to accelerate progress toward converting carbon dioxide into a variety of products.

Plants rely on a process called carbon fixation – turning carbon dioxide from the air into carbon-rich biomolecules ­– for their very existence. That’s the whole point of photosynthesis, and a cornerstone of the vast interlocking system that cycles carbon through plants, animals, microbes and the atmosphere to sustain life on Earth. 

But the carbon fixing champs are not plants, but soil bacteria. Some bacterial enzymes carry out a key step in carbon fixation 20 times faster than plant enzymes do, and figuring out how they do this could help scientists develop forms of artificial photosynthesis to convert the greenhouse gas into fuels, fertilizers, antibiotics and other products.

Now a team of researchers from the Department of Energy’s SLAC National Accelerator Laboratory, Stanford University, Max Planck Institute for Terrestrial Microbiology in Germany, DOE’s Joint Genome Institute (JGI) and the University of Concepción in Chile has discovered how a bacterial enzyme – a molecular machine that facilitates chemical reactions – revs up to perform this feat.

Rather than grabbing carbon dioxide molecules and attaching them to biomolecules one at a time, they found, this enzyme consists of pairs of molecules that work in sync, like the hands of a juggler who simultaneously tosses and catches balls, to get the job done faster. One member of each enzyme pair opens wide to catch a set of reaction ingredients while the other closes over its captured ingredients and carries out the carbon-fixing reaction; then, they switch roles in a continual cycle.  

Read more on the SLAC website

What drives rechargeable battery decay?

How quickly a battery electrode decays depends on properties of individual particles in the battery – at first. Later on, the network of particles matters more.

Rechargeable lithium-ion batteries don’t last forever – after enough cycles of charging and recharging, they’ll eventually go kaput, so researchers are constantly looking for ways to squeeze a little more life out of their battery designs.

Now, researchers at the Department of Energy’s SLAC National Accelerator Laboratory and colleagues from Purdue University, Virginia Tech, and the European Synchrotron Radiation Facility have discovered that the factors behind battery decay actually change over time. Early on, decay seems to be driven by the properties of individual electrode particles, but after several dozen charging cycles, it’s how those particles are put together that matters more.

“The fundamental building blocks are these particles that make up the battery electrode, but when you zoom out, these particles interact with each other,” said SLAC scientist Yijin Liu, a researcher at the lab’s Stanford Synchrotron Radiation Lightsource and a senior author on the new paper. Therefore, “if you want to build a better battery, you need to look at how to put the particles together.”

Read more on the SLAC website

Image: A piece of battery cathode after 10 charging cycles. A machine-learning feature detection and quantification algorithm allowed researchers to automatically single out the most severely damaged particles of interest, which are highlighted in the image.

Credit: Courtesy Yijin Liu/SLAC National Accelerator Laboratory

Giorgio Margaritondo’s #My1stLight

Synchrotron Radiation from a Synchrotron

We must face reality: almost all synchrotron radiation users of today have never seen a synchrotron! As we know, what they call “synchrotrons” are really “storage rings”. Only a tiny minority of elderly, retired scientists worked at real synchrotrons – and were lucky to survive the experience. I am one of them. Indeed, the first time I used synchrotron radiation was in the 1970s at the 1.1 GeV “elettrosincrotrone” of the Frascati National Laboratory. Which in the 1970s was the source for our synchrotron radiation project “PULS”.

How was my experience? Miserable! Contrary to a storage ring, a synchrotron is a pulsed source in which electron bunches are continuously injected, accelerated and dumped. The bunches cause very dangerous radiation, so we could not work close to our experimental chamber when they travelled in the ring. This transformed simple operations into a nightmare. For example, a sample alignment that takes a few minutes at a storage ring required days or weeks — subsequent small adjustments being separated by hours of accelerator operation.

At Frascati, we were dreaming of using the excellent storage ring Adone instead of the synchrotron — but this happened only later. Personally, after months of misery I found a way out when I was hired by Bell Labs in New Jersey. Which, to my relief, was as far as possible from the synchrotron facilities of that time. But I could not escape my destiny: shortly after my arrival, Bell Labs asked me to start experiments at the Wisconsin Synchrotron Radiation Center! Fortunately, the source there was not a synchrotron but the storage ring Tantalus. I could thus appreciate the huge advantage over real synchrotrons. I am indeed convinced from experience that, without the arrival of storage rings, synchrotron radiation research would have died at birth.

Giorgio Margaritondo
Faculté des Sciences de Base, Ecole Polytechnique Fédérale de Lausanne
(EPFL), CH-1020 Lausanne, Switzerland

Image: The Frascati electron synchrotron, where my career in synchrotron radiation started and almost
ended

Rich electronic features of a kagome superconductor

The recently discovered layered kagome metals AV3Sb5 (A=K, Rb, Cs) exhibit diverse correlated phenomena, thought to be linked to so-called Van Hove singularities (VHSs) and flat bands in the material. Using a combination of polarization-dependent angle-resolved photoemission spectroscopy (ARPES) and density-functional theory, researchers led by Professor Ming Shi at the Paul Scherrer Institute directly revealed the sublattice properties of 3d-orbital VHSs and flat bands, as well as topologically non-trivial surface states in CsV3Sb5. The research reveals important insights into the material’s electronic structure and provides a basis for understanding correlation phenomena in the metals.

So-called kagome metals, named after the Japanese woven bamboo pattern their structure resembles, feature symmetrical patterns of interlaced, corner-sharing triangles. This unusual lattice geometry and its inherent features lead, in turn, to curious quantum phenomena such as unconventional, or high-temperature, superconductivity.

The potential for devices that might transport electricity without dissipation at room temperature—as well as a thirst for fundamental theoretical understanding—have led researchers to investigate this new class of quantum materials and try to figure out how electrons interact with the kagome lattice to generate such remarkable features.

A recently discovered class of AV3Sb5 kagome metals, where A can be =K, Rb or Cs, was shown, for instance, to feature bulk superconductivity in single crystals at a maximum Tc of 2.5 at ambient pressure. Researchers suspect that this is a case of unconventional superconductivity, driven by some mechanism other than the phonon exchange that characterizes bonding in the electron-phonon coupled superconducting electron-pairs of conventional superconductivity.

This, as well as other exotic properties observed in the metal, are thought to be connected to its multiple “Van Hove singularities” (VHSs) near the Fermi level. VHSs, associated with the density of states (DOS), or set of different states that electrons may occupy at a particular energy level, can enhance correlation effects when a material is close to or reaches this energy level. If the Fermi level lies in the vicinity of a Van Hove point, the singular DOS determines the physical behavior due to the large number of available low-energy states. In particular, interaction effects get amplified not only in the particle-particle, but also in the particle-hole channels, leading to the notion of competing orders.

Read more on the PSI website

Image: Yong Hu, first author, and Nicholas Clark Plumb, who made the experimental station, at the Surface/Interface Spectroscopy (SIS) beamline of the Swiss Light Source (SLS) (L to R)

Credit: Paul Scherrer Institut / Mahir Dzambegovic

The first direct visual observation of synchrotron light in a laboratory

Lightsources.org has created this short video to mark the 75th Anniversary of the first direct visual observation of synchrotron light in a laboratory. It’s release marks the start of our celebrations, which have been made possible thanks to contributions from our member facilities, guest speakers and members from our around the light source community.

Marking the 75th Anniversary of the 1st direct visible observation of synchrotron light in a laboratory

We are hugely grateful to all those who have taken the time to support our activities. On behalf of all the Lightsources.org members, we hope you enjoy our celebrations, which will include:

The creation of a timeline and a collection of achievements from across our 31 member facilities to be shared on the website and social media Our #My1stLight campaign, which invites light source staff and external researchers to send in their memories of first encounters with synchrotron light. Visit our campaign page to find out more

A special online symposium to mark 75 Years of Science with Synchrotron Light on Thursday 28th April – Registration is open here

Seeing more deeply into nanomaterials

New 3D imaging tool reveals engineered and self-assembled nanoparticle lattices with highest resolution yet—7nm—about 1/100,000 of the width of a human hair

From designing new biomaterials to novel photonic devices, new materials built through a process called bottom-up nanofabrication, or self-assembly, are opening up pathways to new technologies with properties tuned at the nanoscale. However, to fully unlock the potential of these new materials, researchers need to “see” into their tiny creations so that they can control the design and fabrication in order to enable the material’s desired properties.

This has been a complex challenge that researchers from the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Columbia University have overcome for the first time, imaging the inside of a novel material self-assembled from nanoparticles with seven nanometer resolution, about 1/100,000 of the width of a human hair. In a new paper published on April 7, 2022 in Science, the researchers showcase the power of their new high-resolution x-ray imaging technique to reveal the inner structure of the nanomaterial. 

The team designed the new nanomaterial using DNA as a programmable construction material, which enables them to create novel engineered materials for catalysis, optics, and extreme environments. During the creation process of these materials, the different building blocks made of DNA and nanoparticles shift into place on their own based on a defined “blueprint”—called a template—designed by the researchers. However, to image and exploit these tiny structures with x-rays, they needed to convert them into inorganic materials that could withstand x-rays while providing useful functionality. For the first time, the researchers could see the details, including the imperfections within their newly arranged nanomaterials.

Read more on the BNL website

Image: An artist’s impression of how the researchers used x-ray tomography as a magnifying lens to see into the inner structure of nanomaterials

Record time resolution

RESEARCH TEAM DEMONSTRATES BEST PUMP–PROBE TIME RESOLUTION REPORTED SO FAR AT X-RAY FREE-ELECTRON LASER FACILITIES

After being illuminated with light, the atoms in materials react within femtoseconds, i.e. quadrillionths of a second. To observe these reactions in real time, the experiment setup used to capture them must operate with femtosecond time resolution too, otherwise the resulting images will be “blurred”. In a proof-of-principle experiment at the European XFEL, a research team has demonstrated a record time resolution of around 15 femtoseconds—the best resolution reported so far in a pump–probe experiment at an X-ray free-electron laser (FEL) facility, while keeping a high spectral resolution. “These results open up the possibility of doing time-resolved experiments with unprecedented time resolution, enabling the observation of ultrafast processes in materials that were not accessible before,” explains Daniel Rivas from European XFEL, principal investigator of the experiment and first author of the publication in the scientific journal Optica, in which the team from European XFEL and the DESY research centre in Hamburg report their results.

One of the goals of experiments at the European XFEL is to record “molecular movies”, i.e. series of snapshots of dynamic processes taken in extremely rapid succession, which reveal the details of chemical reactions or physical changes in materials at high time resolution. Understanding the molecular rearrangement during such reactions is an essential step towards controlling processes in our natural environment, such as radiation damage in biological systems or photochemical and catalytic reactions. One technique to create such movies is pump–probe spectroscopy, where an optical laser pulse (the “pump” pulse) excites a certain process in a sample and the X-ray laser pulses (the “probe” pulses) are used to take a series of snapshots in order to observe how the process evolves in time.

Read more on the European XFEL website

Image: An ultrashort X-ray pulse and an optical laser pulse interact simultaneously with a neon atom. The X-ray pulse removes an electron from the inner electronic shell and, due to the electromagnetic field of the optical laser that is present at the moment of ionization, the outcoming electron is modulated in energy.

Credit: illustratoren.de/TobiasWuestefeld in cooperation with European XFEL