Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

SLAC scientists invent a way to see attosecond electron motions with an X-ray laser

03.12.2019

Called XLEAP, the new method will provide sharp views of electrons in chemical processes that take place in billionths of a billionth of a second and drive crucial aspects of life

Researchers at the Department of Energy's SLAC National Accelerator Laboratory have invented a way to observe the movements of electrons with powerful X-ray laser bursts just 280 attoseconds, or billionths of a billionth of a second, long.


A SLAC-led team has invented a method, called XLEAP, that generates powerful low-energy X-ray laser pulses that are only 280 attoseconds, or billionths of a billionth of a second, long and that can reveal for the first time the fastest motions of electrons that drive chemistry. This illustration shows how the scientists use a series of magnets to transform an electron bunch (blue shape at left) at SLAC's Linac Coherent Light Source into a narrow current spike (blue shape at right), which then produces a very intense attosecond X-ray flash (yellow).

Credit: Greg Stewart/SLAC National Accelerator Laboratory

The technology, called X-ray laser-enhanced attosecond pulse generation (XLEAP), is a big advance that scientists have been working toward for years, and it paves the way for breakthrough studies of how electrons speeding around molecules initiate crucial processes in biology, chemistry, materials science and more.

The team presented their method today in an article in Nature Photonics.

"Until now, we could precisely observe the motions of atomic nuclei, but the much faster electron motions that actually drive chemical reactions were blurred out," said SLAC scientist James Cryan, one of the paper's lead authors and an investigator with the Stanford PULSE Institute, a joint institute of SLAC and Stanford University.

"With this advance, we'll be able to use an X-ray laser to see how electrons move around and how that sets the stage for the chemistry that follows. It pushes the frontiers of ultrafast science."

Studies on these timescales could reveal, for example, how the absorption of light during photosynthesis almost instantaneously pushes electrons around and initiates a cascade of much slower events that ultimately generate oxygen.

"With XLEAP we can create X-ray pulses with just the right energy that are more than a million times brighter than attosecond pulses of similar energy before," said SLAC scientist Agostino Marinelli, XLEAP project lead and one of the paper's lead authors. "It'll let us do so many things people have always wanted to do with an X-ray laser - and now also on attosecond timescales."

A leap for ultrafast X-ray science

One attosecond is an incredibly short period of time - two attoseconds is to a second as one second is to the age of the universe. In recent years, scientists have made a lot of progress in creating attosecond X-ray pulses. However, these pulses were either too weak or they didn't have the right energy to home in on speedy electron motions.

Over the past three years, Marinelli and his colleagues have been figuring out how an X-ray laser method suggested 14 years ago could be used to generate pulses with the right properties - an effort that resulted in XLEAP.

In experiments carried out just before crews began work on a major upgrade of SLAC's Linac Coherent Lightsource (LCLS) X-ray laser, the XLEAP team demonstrated that they can produce precisely timed pairs of attosecond X-ray pulses that can set electrons in motion and then record those movements. These snapshots can be strung together into stop-action movies.

Linda Young, an expert in X-ray science at DOE's Argonne National Laboratory and the University of Chicago who was not involved in the study, said, "XLEAP is a truly great advance. Its attosecond X-ray pulses of unprecedented intensity and flexibility are a breakthrough tool to observe and control electron motion at individual atomic sites in complex systems."

X-ray lasers like LCLS routinely generate light flashes that last a few millionths of a billionth of a second, or femtoseconds. The process starts with creating a beam of electrons, which are bundled into short bunches and sent through a linear particle accelerator, where they gain energy. Travelling at almost the speed of light, they pass through a magnet known as an undulator, where some of their energy is converted into X-ray bursts.

The shorter and brighter the electron bunches, the shorter the X-ray bursts they create, so one approach for making attosecond X-ray pulses is to compress the electrons into smaller and smaller bunches with high peak brightness. XLEAP is a clever way to do just that.

Making attosecond X-ray laser pulses

At LCLS, the team inserted two sets of magnets in front of the undulator that allowed them to mold each electron bunch into the required shape: an intense, narrow spike containing electrons with a broad range of energies.

"When we send these spikes, which have pulse lengths of about a femtosecond, through the undulator, they produce X-ray pulses that are much shorter than that," said Joseph Duris, a SLAC staff scientist and paper co-first-author. The pulses are also extremely powerful, he said, with some of them reaching half a terawatt peak power.

To measure these incredibly short X-ray pulses, the scientists designed a special device in which the X-rays shoot through a gas and strip off some of its electrons, creating an electron cloud. Circularly polarized light from an infrared laser interacts with the cloud and gives the electrons a kick. Because of the light's particular polarization, some of the electrons end up moving faster than others.

"The technique works similar to another idea implemented at LCLS, which maps time onto angles like the arms of a clock," said Siqi Li, a paper co-first-author and recent Stanford PhD. "It allows us to measure the distribution of the electron speeds and directions, and from that we can calculate the X-ray pulse length."

Next, the XLEAP team will further optimize their method, which could lead to even more intense and possibly shorter pulses. They are also preparing for LCLS-II, the upgrade of LCLS that will fire up to a million X-ray pulses per second - 8,000 times faster than before. This will allow researchers to do experiments they have long dreamed of, such as studies of individual molecules and their behavior on nature's fastest timescales.

###

The XLEAP team included researchers from SLAC; Stanford University; Imperial College, UK; Max Planck Institute for Quantum Optics, Ludwig-Maximilians University Munich, Kassel University, Technical University Dortmund and Technical University Munich in Germany; and DOE's Argonne National Laboratory. Large portions of this project were funded by the DOE Office of Science and through DOE's Laboratory Directed Research and Development (LDRD) program. LCLS is a DOE Office of Science user facility.

Citation: Joseph Duris, Siqi Li et al., Nature Photonics, 2 December 2019 (10.1038/s41566-019-0549-5)

SLAC is a vibrant multiprogram laboratory that explores how the universe works at the biggest, smallest and fastest scales and invents powerful tools used by scientists around the globe. With research spanning particle physics, astrophysics and cosmology, materials, chemistry, bio- and energy sciences and scientific computing, we help solve real-world problems and advance the interests of the nation.

SLAC is operated by Stanford University for the U.S. Department of Energy's Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit energy.gov/science.

Media Contact

Manuel Gnida
mgnida@slac.stanford.edu
415-308-7832

 @SLAClab

http://www.slac.stanford.edu 

Manuel Gnida | EurekAlert!
Further information:
http://dx.doi.org/10.1038/s41566-019-0549-5

Further reports about: Accelerator Electrons SLAC X-ray X-ray bursts X-ray pulses

More articles from Materials Sciences:

nachricht Miniature double glazing: Material developed which is heat-insulating and heat-conducting at the same time
17.01.2020 | Max-Planck-Institut für Polymerforschung

nachricht 3D Printing: New high-Tech Device for Bremen Material Scientists
16.01.2020 | Universität Bremen

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Miniature double glazing: Material developed which is heat-insulating and heat-conducting at the same time

Styrofoam or copper - both materials have very different properties with regard to their ability to conduct heat. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz and the University of Bayreuth have now jointly developed and characterized a novel, extremely thin and transparent material that has different thermal conduction properties depending on the direction. While it can conduct heat extremely well in one direction, it shows good thermal insulation in the other direction.

Thermal insulation and thermal conduction play a crucial role in our everyday lives - from computer processors, where it is important to dissipate heat as...

Im Focus: Fraunhofer IAF establishes an application laboratory for quantum sensors

In order to advance the transfer of research developments from the field of quantum sensor technology into industrial applications, an application laboratory is being established at Fraunhofer IAF. This will enable interested companies and especially regional SMEs and start-ups to evaluate the innovation potential of quantum sensors for their specific requirements. Both the state of Baden-Württemberg and the Fraunhofer-Gesellschaft are supporting the four-year project with one million euros each.

The application laboratory is being set up as part of the Fraunhofer lighthouse project »QMag«, short for quantum magnetometry. In this project, researchers...

Im Focus: How Cells Assemble Their Skeleton

Researchers study the formation of microtubules

Microtubules, filamentous structures within the cell, are required for many important processes, including cell division and intracellular transport. A...

Im Focus: World Premiere in Zurich: Machine keeps human livers alive for one week outside of the body

Researchers from the University Hospital Zurich, ETH Zurich, Wyss Zurich and the University of Zurich have developed a machine that repairs injured human livers and keep them alive outside the body for one week. This breakthrough may increase the number of available organs for transplantation saving many lives of patients with severe liver diseases or cancer.

Until now, livers could be stored safely outside the body for only a few hours. With the novel perfusion technology, livers - and even injured livers - can now...

Im Focus: SuperTIGER on its second prowl -- 130,000 feet above Antarctica

A balloon-borne scientific instrument designed to study the origin of cosmic rays is taking its second turn high above the continent of Antarctica three and a half weeks after its launch.

SuperTIGER (Super Trans-Iron Galactic Element Recorder) is designed to measure the rare, heavy elements in cosmic rays that hold clues about their origins...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

„Advanced Battery Power“- Conference, Contributions are welcome!

07.01.2020 | Event News

 
Latest News

A new 'cool' blue

17.01.2020 | Life Sciences

EU-project SONAR: Better batteries for electricity from renewable energy sources

17.01.2020 | Power and Electrical Engineering

Neuromuscular organoid: It’s contracting!

17.01.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>