Steering the outcome of photoionization in a molecule

An important step towards the understanding and control of photoinduced fragmentation processes in molecules has been achieved in an experiment on the H2 molecule taking advantage of the unique properties of the FERMI free-electron laser source in the vacuum ultraviolet (VUV) photon energy range.
Molecular dissociation, i.e., the breaking of a chemical bond, is governed by the coupling of electronic and nuclear motion and, once understood and controlled in large systems, e.g., by utilizing ultrashort light pulses, has the potential to impact tremendously photochemical and biochemical applications. A team of both experimentalists and theoreticians from France (CNRS, Université Paris-Sud, Université de Bordeaux), Spain (Universidad Autónoma de Madrid), Germany (European XFEL), and Italy (Elettra-Sincrotrone Trieste) has demonstrated that the outcome of dissociative (DI) and nondissociative (NDI) photoionization in the simplest of all molecules, H2, can be controlled exploiting nonlinear two-photon ionization with intense femtosecond pulses in the VUV.
The FERMI seeded free-electron laser is currently the only light source worldwide that provides external users access to bright femtosecond pulses at wavelengths in the VUV up to 100 nm, the energy regime required for studying nonlinear two-photon single-ionization in H2. The high spectral resolution and precise tunability of the 100-fs pulses provided by FERMI made it possible to selectively excite single vibrational levels in the neutral intermediate B state of H2 (blue line in Fig. 1). Absorption of a second VUV photon then leads to NDI or DI into the ionic H2+ ground state (green in Fig. 1) or to DI into the first excited H2+2p continuum (orange in Fig. 1). In single-photon single-ionization of H2, the yield of DI is very low – less than 2%. By contrast, recent ab initiocalculations suggest that the ratio of DI/NDI can be increased significantly in resonance-enhanced two-photon ionization and that it can be controlled by varying the pulse duration between 2 and 10 fs.

>Read more on the Elettra website

Image: (a) Schematic of resonant two-photon ionization viathe B intermediate state (12.51 eV). The grey shaded area shows the Franck-Condon region for one-photon absorption from the H2electronic ground state. The dashed purple arrows visualize the range for the absorption of the second FEL photon. The green (red) horizontal line shows the ionization threshold at 15.43 eV (dissociation limit at 18.08 eV). (b) The experimental photoelectron spectrum shows a clear separation of electrons correlated to NDI and DI. For DI, it is close to the prediction of the Condon-reflection approximation, i.e., the projection of the vibrational wavefunction onto the dissociative 2p continuum state. The infinite-time limit calculation (grey line for the convolution of the contributions from the two first ionization continua) reproduces the main features of the spectrum. The differences between experiment and calculation indicates that at FERMI a timescale between ultrafast dynamics and steady-state excitation is probed.

Light at the end of the last tunnel

X-rays reach instruments HED and MID

During the afternoon and evening hours of Friday 5 October, the DESY accelerator team and the European XFEL photon commissioning team worked together to guide the first X-ray light through the last of the facility’s initial three X-ray beamlines, SASE2, and towards the last of the currently planned European XFEL instruments, the High Energy Density (HED) and Materials Imaging and Dynamics (MID) instruments.

At about midday on Friday, the X-ray light entered the photon tunnel leading to the SASE 2 instruments. To get there, the beam had to pass through a 12 mm horizontal aperture of the shutter collimator about 264 m from the source. In order to make this possible, alignment and vacuum system experts from the DESY accelerator group worked together during the last few months to precisely align the undulator section that generates X-ray laser light from accelerated electrons. This work was based on data obtained during the initial commissioning done in May 2018.

>Read more on the European XFEL website

Image: Screenshot of the first light.

Italy now European XFEL shareholder

On Friday 5 October, the Italian research organisations INFN and CNR officially became shareholders of European XFEL GmbH.

The National Institute for Nuclear Physics (INFN) and the National Research Council (CNR) together now own 2.9% of the company’s shares; one third going to INFN and two thirds to CNR. Italy has been a European XFEL partner country since the foundation of the company. With the acquisition of the shares, INFN and CNR – both designated by Italy as Italian shareholders – now also have full voting rights in the company’s supreme organ, the European XFEL Council. The Italian share of 2.9% in the company corresponds to the Italian contributions to the total European XFEL construction and operation budgets, making Italy the fourth largest funders following Germany, Russia, and France.

>Read more on the European XFEL website

Image: Representatives from DESY, European XFEL, INFN and CNR celebrate after the signing of the accession documents today. From left to right: Veronica Buccheri, INFN; Nicole Elleuche, European XFEL; Roberto Pellegrini, INFN; Rosario Spinella, CNR; Bruno Quarta, INFN; Reinhard Brinkmann, DESY; Robert Feidenhans’l, European XFEL; Christian Harringa, DESY.
Credit: European XFEL

First experiments reveal unknown structure of antibiotics killer

DESY-led international collaboration obtains first scientific results from European XFEL

An international collaboration led by DESY and consisting of over 120 researchers has announced the results of the first scientific experiments at Europe’s new X-ray laser European XFEL. The pioneering work not only demonstrates that the new research facility can speed up experiments by more than an order of magnitude, it also reveals a previously unknown structure of an enzyme responsible for antibiotics resistance. “The groundbreaking work of the first team to use the European XFEL has paved the way for all users of the facility who greatly benefit from these pioneering experiments,” emphasises European XFEL managing director Robert Feidenhans’l. “We are very pleased – these results show that the facility works even better than we had expected and is ready to deliver new scientific breakthroughs.” The scientists present their results, including the first new protein structure solved at the European XFEL, in the journal Nature Communications.

“Being at a totally new class of facility we had to master many challenges that nobody had tackled before,” says DESY scientist Anton Barty from the Center for Free-Electron Laser Science (CFEL), who led the team of about 125 researchers involved in the first experiments that were open to the whole scientific community. “I compare it to the maiden flight of a novel aircraft: All calculations and assembly completed, everything says it will work, but not until you try it do you know whether it actually flies.”

The 3.4 kilometres long European XFEL is designed to deliver X-ray flashes every 0.000 000 220 seconds (220 nanoseconds). To unravel the three-dimensional structure of a biomolecule, such as an enzyme, the pulses are used to obtain flash X-ray exposures of tiny crystals grown from that biomolecule. Each exposure gives rise to a characteristic diffraction pattern on the detector. If enough such patterns are recorded from all sides of a crystal, the spatial structure of the biomolecule can be calculated. The structure of a biomolecule can reveal much about how it works.

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

Image: Artist’s impression of the experiment: When the ultra-bright X-ray flashes (violet) hit the enzyme crystals in the water jet (blue), the recorded diffraction data allow to reconstruct the spatial structure of the enzyme (right).
Credit: DESY/Lucid Berlin

European XFEL celebrates one year of user operation

At the beginning of September, staff and users of the world’s largest X-ray laser facility celebrate a successful first year of user operation.

Since September 2017, over 500 scientists from more than 20 countries from across the globe have visited European XFEL in Schenefeld in north Germany for their week long experiments. The first research results were published just days ago on 28 August; more publications are in preparation for the following weeks.

For the first and second round of experiments scheduled from September 2017 to October 2018, 123 international groups of scientists submitted their proposals for experiment. Of these, 26 groups were selected by an international panel of experts to carry out their research at the two instruments—the SPB/SFX instrument (Single Particles, Clusters and Biomolecules / Serial Femtosecond Crystallography) and the FXE instrument (Femtosecond X-Ray Experiments). The experiments range from method development to biomolecule structure determination and studies of extremely fast processes in small molecules and chemical reactions. Submissions for the user experiments at the remaining four instruments scheduled to start operation between the end of 2018 and mid-2019 are currently being evaluated.

>Read more on the European XFEL website

Image: The European XFEL birthday cake shows the map of the underground tunnel system. It was cut by Nicole Elleuche (Administrative Director European XFEL), Robert Feidenhans’l (Managing Director European XFEL), as well as Maria Faury (Chair of the European XFEL Council) and distributed to European XFEL and DESY staff. 

First European XFEL research results published

High number of X-ray pulses per second reduces time needed for the study of biological structures.

Just days before the first anniversary of the start of European XFEL user operation, the first results based on research performed at the facility have been published. In the journal Nature Communications, the scientists, headed by Prof. Ilme Schlichting from Max-Planck-Institute for Medical Research in Heidelberg, Germany, together with colleagues from Rutgers State University of New Jersey, USA, France, DESY and European XFEL, describe their work using the intense X-ray laser beam to determine the 3D structure of several proteins. They demonstrate, for the first time that, under the conditions used at the time of the experiment an increased number of X-ray pulses per second as produced by the European XFEL can be successfully used to determine the structure of biomolecules. As much faster data collection is therefore possible, the time needed for an experiment could be significantly shortened. The detailed determination of the 3D structure of biomolecules is crucial for providing insights into informing the development of  novel drugs to treat diseases.

Prof. Ilme Schlichting said: “Our work shows that under the conditions used data can be collected at European XFEL at a rate much faster than has ever been previously possible. As the time and cost of experiments decrease, very soon many more researchers will be able to perform experiments at high repetition rate X-ray lasers. Our results are therefore of interest not only tor the fields of biology and medicine, but also physics, chemistry and other disciplines.”

>Read more on the European XFEL website

Image: Guest scientist Tokushi Sato working at the sample chamber of the SPB/SFX instrument.
Credit: European XFEL

Maria Faury appointed new chair of the European XFEL Council

As of the 1 July 2018, Maria Faury is the new chair of the European XFEL council, the highest governing body of the company. Maria Faury has an engineering background and is Director of International Affairs and Large Research Infrastructures of the Fundamental Research Division at the Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA) in France. She has represented CEA, one of the two European XFEL partners in France, on the council since 2014. She will succeed Prof. Martin Meedom Nielsen from the Technical University of Denmark (DTU), who, having served two terms as chair, will continue to support the work of European XFEL as vice chair. The current vice chair, Prof. Lars Börjesson from Chalmers University of Technology in Gothenburg, will again become a member of the Swedish delegation on the council.

Maria Faury said: “It will be an honor, and a real pleasure for me to chair the European XFEL Council. Since 2014, I have had the chance to witness the progress in the construction of the facility and have been impressed by the unwavering involvement of the staff, the management and the stakeholders. European XFEL is now operating and attracting scientists from all over the world, starting to deliver excellent science. The coming years will be very exciting and all together we will ensure that European XFEL remains a world-leading facility. I fully trust Robert Feidenhans’l and his team and I am very happy to work more closely with them in the future. I would like to thank Martin Meedom Nielson who has chaired the council in such a nice, open and positive way. He has been very inspiring to us and I am happy he will continue as vice chair.”

>Read more on the European XFEL website

Picture: Maria Faury, new chair of the European XFEL Council

Sunshine, science and seed bombs at European XFEL’s first open day in Schenefeld

More than 2500 visitors to event in Schenefeld

On Saturday, under sunny spring skies, more than 2500 visitors attended European XFEL’s first Open Day on the campus in Schenefeld. Guests of all ages enjoyed a diverse and varied program of activities, talks, exhibitions and tours, giving an insight into the work, staff and community of the new research centre.

Schleswig Holsteins Minister for Science Karin Prien, Schenefeld Mayor Christiane Küchenhof and European XFEL Managing Director Prof. Robert Feidenhans’l officially opened the event just after midday. “It’s great to see so much interest in our facility!” said Feidenhans’l. “We are very proud to be able to present our facility. More than 150 staff members of European XFEL, as well as our campus partners have worked really hard in preparation for this premiere. Seeing so much enthusiasm for science among people of all age groups is an additional boost for our work during the next few weeks and months. I thank all staff member and campus partners for their support that has made this day possible.” Later Hamburg’s second mayor and science minister Katharina Fegebank also visited the event and greeting the visitors.

>Read more on the European XFEL website

Image: Left to right: Schenefeld Mayor Christiane Küchenhof, European XFEL Administrative Director Nicole Elleuche, Schleswig-Holstein Science Minister Karin Prien, and European XFEL Managing Director Prof. Robert Feidenhans’l during the visit to the tunnel.
Credit:
European XFEL

 

Third light source generates first X-ray light

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

Serial crystallography develops by leaps and bounds at the ESRF

Serial crystallography is a new way of studying macromolecular structures using synchrotron and X-FEL sources around the world.

The Structural Biology group at the ESRF is continuously developing new methods to advance the field. Two articles describing advances made are published today in Acta Crystallographica Section D.

“On the Structural Biology Group beamlines one of the ultimate aims is that users can define protocols for experiments, click ‘go’ and let the experiments run by themselves”, explains Gordon Leonard, head of the Structural Biology group at the ESRF. With this idea in mind and to get as much information as possible from the samples available, the team has already adopted serial crystallography, a technique which involves taking diffraction data from many, sometimes hundreds or thousands, of crystals in order to assemble a complete dataset, piece by piece. Indeed, the members of the group are constantly developing new ways to improve the method through collaboration involving scientists from the ESRF, DESY, the Hamburg Centre for Ultrafast Imaging, the European X-FEL and the University of Hamburg.

>Read more on the European Synchrotron website

Image: Daniele de Sanctis on the ID29 beamline.
Credit: S. Candé.

The United Kingdom officially joins European XFEL

At signing ceremony in Berlin, UK becomes twelfth member

Today, the UK joined European XFEL as the research organization’s twelfth member state. In a ceremony at the British Embassy in Berlin, representatives of the UK government and the other contract parties including the German federal government signed the documents to join the European XFEL Convention. The UK’s contribution will amount to 26 million Euro, or about 2% of the total construction budget of 1.22 billion Euro (both in 2005 prices) and an annual contribution of about 2 % to the operation budget. The UK will be represented in European XFEL by the Science and Technology Facilities Council (STFC) as shareholder.

Chair of the European XFEL Council Prof. Martin Meedom Nielsen who was present at the signing said: “All member states are very happy that the United Kingdom now officially joins the European XFEL. The UK science community has been very active in the project since the very beginning, and their contribution of ideas and know-how has been always highly appreciated. Together, we will maintain and develop the European XFEL as a world leading facility for X-ray science.”

>Read more on the European XFEL website

Picture: Buddy Bartelsen for British Embassy Berlin

European XFEL starts operation of second X-ray light source

Another important milestone achieved in the development of the facility

The second X-ray light source has successfully been taken into operation at European XFEL, the world’s largest X-ray laser located in the Hamburg metropolitan region. The X-ray light source SASE3 successfully produced X-ray laser light flashes in one of the underground tunnels. SASE3 will serve two experiment stations scheduled to begin user operation at the end of the year. Since the start of operation in September 2017, 340 scientists from across the globe have already used the facility for their research. The successful start of operation of the new SASE 3 source will enable the facility to increase the number of users further.

European XFEL Managing Director Prof. Robert Feidenhans’ said: “The construction and commissioning of the new light source are complex processes, for which we and our DESY colleagues have been preparing intensely for these last weeks and months. We are very happy that the commissioning of this second light source SASE 3 has also run so smoothly, and that both sources, SASE1 and SASE3, produce light simultaneously. For this I would like to thank all those involved, in particular the accelerator team from DESY. We continue to be on schedule to start operation at all four experiment stations currently under construction, beginning with the first two instruments in November. The remaining two will start operation at the beginning of 2019. This will increase our current capacity threefold by mid 2019.”

>Read more on the European XFEL website

Image of the first X-ray laser beam in the tunnel from the European XFEL’s SASE3 undulator. SASE3 generates X-rays with a wavelength similar to the width of an atom. Those X-rays will be used to study subjects such as the formation and breaking of chemical bonds and the emergence of special properties such as semiconductivity in materials.

Record number of participants at User Meeting

Celebrating a year of glorious firsts and outlining future developments

“Welcome to the first European XFEL user meeting with actual users!” said Martin Meedom Nielsen, head of the European XFEL council as he opened the three day event on 24 January in front of a packed lecture hall on the DESY campus in Hamburg. With 1200 registered participants from ca. 100 institutions from 30 countries, this year’s joint European XFEL and DESY photon science users’ meeting, the first since operation began, was the biggest yet.

Meedom Nielsen and European XFEL Managing Director Robert Feidenhans’l started the meeting by summarizing the achievements and developments of the last year and thanking everyone who had contributed to the facility’s success. “It has been a fantastic year,” said Feidenhans’l looking back on his first year as director of the facility, “a tough year and we have worked really hard, but a fantastic year.” “2017 was a year of glorious firsts” said Meedom Nielsen, highlighting especially the facility’s inauguration in September and the beams of laser light that shone across the city to mark the occasion. “Hamburg was shining for European XFEL, and European XFEL was shining back” he said.

>Read more on the European XFEL website

 Photo Credit: European XFEL

 

1200 participants at annual users’ meeting

Record number of attendees at the joint DESY and European XFEL event

The joint meeting of users of DESY’s research light sources and the European XFEL X-ray laser once again drew a record number of attendees to Hamburg. Some 1200 participants from nearly 100 institutions from around 30 countries have registered for the three-day event (24-26 January) held at DESY, more than ever before. A particular highlight this year is the beginning of scientific user operation at the European XFEL, from which first results were presented.

“The users’ meeting in Hamburg is the largest in the world for research with X-ray light sources, and we are very proud of that,” emphasised DESY Director Helmut Dosch. “The tremendous interest reflects the importance of these unique research tools for all natural sciences and beyond.” DESY’s research director for photon science, Edgar Weckert, added: “With the X-ray lasers FLASH and European XFEL and the storage-ring-based X-ray source PETRA III, the metropolitan region offers a worldwide unique combination of high-intensity research light sources that serve a wide range of disciplines, from biology and medicine to energy, material and earth science to physics, chemistry and even art history.”

Image: DESY, Axel Heimken

Behind the scenes at European XFEL

Users and staff give their impressions of the first experiments

In mid-September, fourteen metres under the European XFEL building in north Germany, users started their experiments at the first two instruments to go online: the FXE Femtosecond X-Ray Experiments (FXE) instrument, and the Single Particles, Clusters, and Biomolecules and Serial Femtosecond Crystallography (SPB/SFX) instrument. But what was it like to be among the first users to ever do experiments at the facility, and how did the European XFEL staff members who supported them during their stay experience it all? We asked some for our users and staff for their impressions.

LEAPS initiative launched by European light source facilities

European XFEL founding member of the League of European Accelerator based Photon Sources (LEAPS)

European XFEL joined other European light source facilities and organisations today in Brussels to launch a new collaborative initiative to drive a more efficient, effective and collaborative use of light source technologies. The League of European Accelerator based Photon Sources (LEAPS) brings together 16 research organisations from across Europe, including European XFEL.  The light sources aresuper-microscopes’ that produce exceptionally intense beams of X-rays, ultra-violet and infrared light enabling the exploration of samples in the tiniest of details. LEAPS consists mainly of synchrotron light sources such as DESY’s PETRA III, and free-electron lasers such as the European XFEL.

While European light sources have been working alongside each other for years, the LEAPS members strive for closer collaboration and cooperation. They share a common vision to drive forward the development of common technologies, to strengthen economies and create employment, and to support industries to make better use of available instruments and techniques. Together, they aim to inspire emerging technologies and innovations, and to foster a stronger skills base across Europe.