Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Study provides recipe for 'supercharging' atoms with X-ray laser

12.11.2012
Researchers using the Linac Coherent Light Source (LCLS) at the U.S. Department of Energy's (DOE) SLAC National Accelerator Laboratory have found a way to strip most of the electrons from xenon atoms, creating a "supercharged," strongly positive state at energies previously thought too low.

The findings, which defy expectations and theory, could help scientists deliberately induce the high levels of damage needed to study extreme states of matter or ward off damage in samples they're trying to image. The results were reported this week in Nature Photonics.


The ultra-bright X-ray laser pulses of the Linac Coherent Light Source at SLAC National Accelerator Laboratory can be used to strip electrons away from atoms, creating ions with strong charges. The ability to interact with atoms is critical for making the highest resolution images of molecules and movies of chemical processes.

Credit: Greg Stewart/SLAC National Accelerator Laboratory


Specialized equipment known as the CAMP chamber, pictured here, played a key role in advanced research at SLAC's free-electron laser, the Linac Coherent Light Source. A new paper details experiments with CAMP that observed a record supercharged state in xenon atoms. The equipment was on loan to SLAC through a collaboration with the Max Planck Society Advanced Study Group.

Credit: Brad Plummer/SLAC National Accelerator Laboratory

While the powerful X-rays of LCLS inevitably destroy the samples being studied, delaying damage – even for millionths of billionths of a second – can prove critical in producing detailed images and other data.

"Our results give a 'recipe' for maximizing the loss of electrons in a sample," said Daniel Rolles, a researcher for the Max Planck Advanced Study Group at the Center for Free-Electron Laser Science in Hamburg, Germany, who led the experiments. "For instance, researchers can use our findings if they're interested in creating a very highly charged plasma. Or, if the supercharged state isn't part of the study, they can use our findings to know what X-ray energies to avoid."

Just as a stretched guitar string can vibrate and sustain a note, a specific tuning of the laser's properties can cause atoms and molecules to resonate. The resonance excites the atoms and causes them to shake off electrons at a rate that otherwise would require higher energies.

While it is common knowledge that triggering resonances in atoms will affect their charged states, "it was not clear to anybody what a dramatic effect this could have in heavy atoms when they are being ionized by a source like LCLS," Rolles said. "It was the highest charge state ever observed with a single X-ray pulse, which shows that the existing theoretical approaches have to be modified."

The team had previously used a laser facility in Germany to expose various atoms and molecules to pulses of ultraviolet light, and was eager to use the higher-energy LCLS for further studies.

"The LCLS experiment pushed the charged state to an unprecedented and unexpected extreme – more than doubling the expected energy absorbed per atom and ejecting dozens of electrons," said Benedikt Rudek from the Max Planck Advanced Study Group, who analyzed the data.

In addition to creating or avoiding supercharged plasma states in experiments, Rolles said the "dramatic change" caused by resonance in the absorption of X-ray energy could someday be exploited to improve the resolution of images captured in LCLS experiments.

"Most biological samples have some heavy atoms embedded, for instance," Rolles said, and in some experiments, avoiding the resonance trigger might prevent rapid damage to those atoms.

The researchers have since done similar LCLS experiments involving the heavy element krypton and molecular systems that contain other heavy atoms, said Artem Rudenko of Kansas State University, who led a recent follow-up experiment.

The team's precise measurements were made possible by a sophisticated experimental station built by the Max Planck Advanced Study Group in Germany. In total, the equipment weighed about 11 tons and was shipped to SLAC in 40 crates. It stayed at LCLS for three years and was used in more than 20 experiments ranging from atomic and molecular physics to material sciences and bio-imaging.

"Reassembling this machine at LCLS within one month and then commissioning it and doing a science experiment in only seven days was an absolutely incredible feat," said Rolles.

The research team included scientists from 19 research centers, including: Max Planck Advanced Study Group and several Max Planck institutes, PNSensor GmbH, Technical University of Berlin, Jülich Research Center, University of Hamburg and Physikalisch-Technische Bundesanstalt in Germany; SLAC and Western Michigan and Kansas State universities in the U.S.; University of Pierre and Marie Curie and National Center for Scientific Research in France; and Kyoto and Tohoku universities in Japan.

LCLS is supported by DOE's Office of Science.

SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the U.S. Department of Energy Office of Science. To learn more, please visit www.slac.stanford.edu.

DOE's 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, please visit science.energy.gov.

Andy Freeberg | EurekAlert!
Further information:
http://www.slac.stanford.edu

More articles from Process Engineering:

nachricht New process for cell transfection in high-throughput screening
21.03.2016 | Laser Zentrum Hannover e.V.

nachricht Sustainable products: Fraunhofer LBF investigates recycling of halogen-free flame retardant
17.02.2016 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Meteoriteneinschlag im Nano-Format

Mit energiereichen Ionen lassen sich erstaunliche Nanostrukturen auf Kristalloberflächen erzeugen. Experimente und Berechnungen der TU Wien können diese Effekte nun erklären.

Ein Meteorit, der in flachem Winkel auf die Erde trifft, kann gewaltige Verwüstungen anrichten: Er schrammt über die Erdoberfläche und legt oft eine lange...

Im Focus: Flexibel statt starr

Gezielter und effizienter Transport zellulärer Frachten durch physikalischen Mechanismus

Damit Zellen richtig funktionieren können, müssen Frachten innerhalb der Zelle ständig von einem Ort zum anderen transportiert werden, wobei es ähnlich zugeht...

Im Focus: Elektronen am Tempolimit

Elektronische Bauteile werden seit Jahren immer schneller und machen damit leistungsfähige Computer und andere Technologien möglich. Wie schnell sich Elektronen mit elektrischen Feldern letztendlich kontrollieren lassen, haben jetzt Forscher an der ETH Zürich untersucht. Ihre Erkenntnisse sind wichtig für die Petahertz-Elektronik der Zukunft.

Geschwindigkeit mag keine Hexerei sein, doch sie ist die Grundlage für Technologien, die nicht selten wie Magie anmuten. Moderne Computer etwa sind so...

Im Focus: Forscher beobachten, wie Chaperone defekte Proteine erkennen

Proteine, auch Eiweiße genannt, erfüllen in unserem Körper lebenswichtige Funktionen: Sie transportieren Stoffe, bekämpfen Krankheitserreger oder fungieren als Katalysatoren. Damit diese Prozesse zuverlässig funktionieren, müssen die Proteine eine definierte dreidimensionale Struktur annehmen. Molekulare Faltungshelfer, die sogenannten Chaperone, kontrollieren den Strukturierungsprozess. Ein Forscherteam unter der Beteiligung der Technischen Universität München (TUM) konnte nun herausfinden, wie Chaperone besonders gefährliche Fehler in diesem Strukturierungsprozess erkennen. Die Ergebnisse wurden im Fachmagazin "Molecular Cell" veröffentlicht.

Chaperone sind sozusagen die TÜV-Prüfer der Zelle. Es handelt sich um Proteine, die wiederum andere Proteine auf Qualitätsmängel untersuchen, bevor diese die...

Im Focus: Mikroskopieren mit einzelnen Ionen

Neuartiges Ionenmikroskop nutzt einzelne Ionen, um Abbildungen mit einer Auflösung im Nanometerbereich zu erzeugen

Wissenschaftler um Georg Jacob von der Johannes Gutenberg-Universität Mainz haben ein Ionenmikroskop entwickelt, das nur mit exakt einem Ion pro Bildpixel...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Innovative Citizen 2016: Festival für demokratischere Technik

29.08.2016 | Veranstaltungen

Internationale Jahrestagung der Gesellschaft für Operations Research

29.08.2016 | Veranstaltungen

VDE und IEEE veranstalten Weltkongress der Consumer-Elektronik auf der IFA

26.08.2016 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Reinraum on Demand

29.08.2016 | Verfahrenstechnologie

EU-Projekt LIAA: Montagelösungen für Mensch-Roboter-Teams

29.08.2016 | Energie und Elektrotechnik

Nur schlank reicht nicht mehr

29.08.2016 | Verfahrenstechnologie