Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

X-ray laser takes aim at cosmic mystery

13.12.2012
An international collaboration including researchers from Lawrence Livermore National Laboratory has refined a key process in understanding extreme plasmas such as those found in the sun, stars, at the rims of black holes and galaxy clusters.

In short, the team identified a new solution to an astrophysical phenomenon through a series of laser experiments.


A photograph of the instrument setup for an astrophysics experiment at the SLAC's Linac Coherent Light Source (LCLS), a powerful X-ray laser. The experiment was conducted in the Soft X-ray hutch using this electron beam ion trap, or EBIT, built at the Max Planck Institute in Heidelberg, Germany. Photo by Jose R. Crespo Lopez-Urrutia, Max Planck Institute for Nuclear Physics

In the new research, appearing in the Dec. 13 edition of the journal Nature, scientists looked at highly charged iron using the Linac Coherent Light Source (LCLS) free-electron laser. Highly charged iron produces some of the brightest X-ray emission lines from hot astrophysical objects, including galaxy clusters, stellar cornea and the emission of the sun.

The experiment helped scientists understand why observations from orbiting X-ray telescopes do not match theoretical predictions, and paves the way for future X-ray astrophysics research using free-electron lasers such as LCLS. LCLS allows scientists to use an X-ray laser to measure atomic processes in extreme plasmas in a fully controlled way for the first time.

The highly charged iron spectrum doesn't fit into even the best astrophysical models. The intensity of the strongest iron line is generally weaker than predicted. Hence, an ongoing controversy has emerged whether this discrepancy is caused by incomplete modeling of the plasma environment or by shortcomings in the treatment of the underlying atomic physics.

"Our measurements suggest that the poor agreement is rooted in the quality of the underlying atomic wave functions rather than in insufficient modeling of collision processes," said Peter Beiersdorfer, a physicist at Lawrence Livermore and one of the initiators of the project.

Greg Brown, a team member from Livermore, said: "Measurements conducted at the LCLS will be important for interpreting X-ray emissions from a plethora of sources, including black holes, binary stars, stellar coronae and supernova remnants, to name a few."

Many astrophysical objects emit X-rays, produced by highly charged particles in superhot gases or other extreme environments. To model and analyze the intense forces and conditions that cause those emissions, scientists use a combination of computer simulations and observations from space telescopes, such as NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton. But direct measurements of those conditions are hard to come by.

In the LCLS experiments, the focus was on plus-16 iron ions, a supercharged form of iron. The iron ions were created and captured using a device known as an electron beam ion trap, or EBIT. Once captured, their properties were probed and measured using the high-precision, ultra brilliant LCLS X-ray laser.

Some collaborators in the experiments have already begun working on new calculations to improve the atomic-scale astrophysical models, while others analyze data from followup experiments conducted at LCLS in April. If they succeed, LCLS may see an increase in experiments related to astrophysics.

"Almost everything we know in astrophysics comes from spectroscopy," said team member Maurice Leutenegger, of NASA's Goddard Space Flight Center, who participated in the study. Spectroscopy is used to measure and study X-rays and other energy signatures, and the LCLS results are valuable in a "wide variety of astrophysical contexts," he said.

The EBIT instrument used in the experiments was developed at the Max Planck Institute for Nuclear Physics and will be available to the entire community of scientists doing research at the LCLS. Livermore has been a pioneer in EBITs. Various EBIT devices have been operational at LLNL for more than 25 years. This was the first time that an EBIT was coupled to an X-ray laser, opening up an entirely new venue for astrophysics research, according to Beiersdorfer.

Researchers from SLAC National Accelerator Laboratory; the Max Planck Institute for Nuclear Physics in Heidelberg, Germany; NASA Goddard Space Flight Center; the Center for Free-Electron Laser Science; GSI Helmholtz Center for Heavy Ion Research; and Giessen, Bochum, Erlangen-Nuremberg and Heidelberg universities in Germany; Kavli Institute for Particle Astrophysics and Cosmology at SLAC; and TRIUMF in Canada also collaborated in the LCLS experiments.

Founded in 1952, Lawrence Livermore National Laboratory provides solutions to our nation's most important national security challenges through innovative science, engineering and technology. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administration.

Anne Stark | EurekAlert!
Further information:
http://www.llnl.gov

More articles from Physics and Astronomy:

nachricht NASA scientist suggests possible link between primordial black holes and dark matter
25.05.2016 | NASA/Goddard Space Flight Center

nachricht The dark side of the fluffiest galaxies
24.05.2016 | Instituto de Astrofísica de Canarias (IAC)

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Computational High-Throughput-Screening findet neue Hartmagnete die weniger Seltene Erden enthalten

Für Zukunftstechnologien wie Elektromobilität und erneuerbare Energien ist der Einsatz von starken Dauermagneten von großer Bedeutung. Für deren Herstellung werden Seltene Erden benötigt. Dem Fraunhofer-Institut für Werkstoffmechanik IWM in Freiburg ist es nun gelungen, mit einem selbst entwickelten Simulationsverfahren auf Basis eines High-Throughput-Screening (HTS) vielversprechende Materialansätze für neue Dauermagnete zu identifizieren. Das Team verbesserte damit die magnetischen Eigenschaften und ersetzte gleichzeitig Seltene Erden durch Elemente, die weniger teuer und zuverlässig verfügbar sind. Die Ergebnisse wurden im Online-Fachmagazin »Scientific Reports« publiziert.

Ausgangspunkt des Projekts der IWM-Forscher Wolfgang Körner, Georg Krugel und Christian Elsässer war eine Neodym-Eisen-Stickstoff-Verbindung, die auf einem...

Im Focus: University of Queensland: In weniger als 2 Stunden ans andere Ende der Welt reisen

Ein internationales Forschungsteam, darunter Wissenschaftler der University of Queensland, hat im Süden Australiens einen erfolgreichen Hyperschallgeschwindigkeitstestflug absolviert und damit futuristische Reisemöglichkeiten greifbarer gemacht.

Flugreisen von London nach Sydney in unter zwei Stunden werden, dank des HiFiRE Programms, immer realistischer. Im Rahmen dieses Projekts werden in den...

Im Focus: Computational high-throughput screening finds hard magnets containing less rare earth elements

Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.

The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...

Im Focus: Mit atomarer Präzision: Technologien für die übernächste Chipgeneration

Im Projekt »Beyond EUV« entwickeln die Fraunhofer-Institute für Lasertechnik ILT in Aachen und für angewandte Optik und Feinmechanik IOF in Jena wesentliche Technologien zur Fertigung einer neuen Generation von Mikrochips mit EUV-Strahlung bei 6,7 nm. Die Strukturen sind dann kaum noch dicker als einzelne Atome und ermöglichen besonders hoch integrierte Schaltkreise zum Beispiel für Wearables oder gedankengesteuerte Prothesen.

Gordon Moore formulierte 1965 das später nach ihm benannte Gesetz, wonach sich alle ein bis zwei Jahre die Komplexität integrierter Schaltungen verdoppelt. Er...

Im Focus: Ein negatives Enzym liefert positive Resultate

In den letzten zwanzig Jahren hat die Chemie viele wichtige Instrumente und Verfahren für die Biologie hervorgebracht. Heute können wir Proteine herstellen, die in der Natur bisher nicht vorkommen. Es lassen sich Bilder von Ausschnitten lebender Zellen aufnehmen und sogar einzelne Zellen in lebendigen Tieren beobachten. Diese Woche haben zwei Forschungsgruppen der Universitäten Basel und Genf, die beide dem Nationalen Forschungsschwerpunkt Molecular Systems Engineering angehören, im Forschungsmagazin «ACS Central Science» präsentiert, wie man ein nicht-natürliches Protein designt, das völlig neue Fähigkeiten aufweist.

Proteine sind die Arbeitspferde jeder Zelle. Sie bestehen aus Aminosäurebausteinen, die als Kette verbunden sind, welche sich zu funktionalen Maschinen...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

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

DFG unterstützt Kongresse und Tagungen - Juli 2016

25.05.2016 | Veranstaltungen

"European Conference on Modelling and Simulation" an der OTH Regensburg

25.05.2016 | Veranstaltungen

Fachtagung »Magnetwerkstoffe und Seltene Erden«

25.05.2016 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

ILA 2016: Additive Produktion ­einsatzfähiger Bauteile durch effiziente Prozessketten

25.05.2016 | Messenachrichten

Reliable in-line inspections of high-strength automotive body parts within seconds

25.05.2016 | Messenachrichten

Wie Zellen Barrieren überwinden

25.05.2016 | Förderungen Preise