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 A 100-year-old physics problem has been solved at EPFL
23.06.2017 | Ecole Polytechnique Fédérale de Lausanne

nachricht Quantum thermometer or optical refrigerator?
23.06.2017 | National Institute of Standards and Technology (NIST)

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Klima-Satellit: Mit robuster Lasertechnik Methan auf der Spur

Hitzewellen in der Arktis, längere Vegetationsperioden in Europa, schwere Überschwemmungen in Westafrika – mit Hilfe des deutsch-französischen Satelliten MERLIN wollen Wissenschaftler ab 2021 die Emissionen des Treibhausgases Methan auf der Erde erforschen. Möglich macht das ein neues robustes Lasersystem des Fraunhofer-Instituts für Lasertechnologie ILT in Aachen, das eine bisher unerreichte Messgenauigkeit erzielt.

Methan entsteht unter anderem bei Fäulnisprozessen. Es ist 25-mal wirksamer als das klimaschädliche Kohlendioxid, kommt in der Erdatmosphäre aber lange nicht...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: Die Schweiz in Pole-Position in der neuen ESA-Mission

Die Europäische Weltraumagentur ESA gab heute grünes Licht für die industrielle Produktion von PLATO, der grössten europäischen wissenschaftlichen Mission zu Exoplaneten. Partner dieser Mission sind die Universitäten Bern und Genf.

Die Europäische Weltraumagentur ESA lanciert heute PLATO (PLAnetary Transits and Oscillation of stars), die grösste europäische wissenschaftliche Mission zur...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

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

Von Batterieforschung bis Optoelektronik

23.06.2017 | Veranstaltungen

10. HDT-Tagung: Elektrische Antriebstechnologie für Hybrid- und Elektrofahrzeuge

22.06.2017 | Veranstaltungen

„Fit für die Industrie 4.0“ – Tagung von Hochschule Darmstadt und Schader-Stiftung am 27. Juni

22.06.2017 | Veranstaltungen

 
VideoLinks
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Radioaktive Elemente in Cassiopeia A liefern Hinweise auf Neutrinos als Ursache der Supernova-Explosion

23.06.2017 | Physik Astronomie

Dünenökosysteme modellieren

23.06.2017 | Ökologie Umwelt- Naturschutz

Makro-Mikrowelle macht Leichtbau für Luft- und Raumfahrt effizienter

23.06.2017 | Materialwissenschaften