World's Most Powerful X-Ray Laser Creates 2-Million-Degree Matter

This photograph shows the interior of a Linac Coherent Light Source SXR experimental chamber, set up for an investigation to create and measure a form of extreme, 2-million-degree matter known as “hot, dense matter.” The central part of the frame contains the holder for the material that will be converted by the powerful LCLS laser into hot, dense matter. To the left is an XUV spectrometer and to the right is a small red laser set up for alignment and positioning. (Credit: Photo courtesy of University of Oxford/Sam Vinko)

Researchers working at the U.S. Department of Energy's (DOE) SLAC National Accelerator Laboratory have used the world's most powerful X-ray laser to create and probe a 2-million-degree piece of matter in a controlled way for the first time. This feat, reported inNature, takes scientists a significant step forward in understanding the most extreme matter found in the hearts of stars and giant planets, and could help experiments aimed at recreating the nuclear fusion process that powers the sun.

The experiments were carried out at SLAC's Linac Coherent Light Source (LCLS), whose rapid-fire laser pulses are a billion times brighter than those of any X-ray source before it. Scientists used those pulses to flash-heat a tiny piece of aluminum foil, creating what is known as "hot dense matter," and took the temperature of this solid plasma -- about 2 million degrees Celsius. The whole process took less than a trillionth of a second.

"The LCLS X-ray laser is a truly remarkable machine," said Sam Vinko, a postdoctoral researcher at Oxford University and the paper's lead author. "Making extremely hot, dense matter is important scientifically if we are ultimately to understand the conditions that exist inside stars and at the center of giant planets within our own solar system and beyond."

Scientists have long been able to create plasma from gases and study it with conventional lasers, said co-author Bob Nagler of SLAC, an LCLS instrument scientist. But no tools were available for doing the same at solid densities that cannot be penetrated by conventional laser beams.

"The LCLS, with its ultra-short wavelengths of X-ray laser light, is the first that can penetrate a dense solid and create a uniform patch of plasma -- in this case a cube one-thousandth of a centimeter on a side -- and probe it at the same time," Nagler said.

The resulting measurements, he said, will feed back into theories and computer simulations of how hot, dense matter behaves. This could help scientists analyze and recreate the nuclear fusion process that powers the sun.

"Those 60 hours when we first aimed the LCLS at a solid were the most exciting 60 hours of my entire scientific career," said Justin Wark, leader of the Oxford group. "LCLS is really going to revolutionize the field, in my view."

Story Source:

The above story is reprinted from materials provided byDOE/SLAC National Accelerator Laboratory.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

---

Journal Reference:

1. S. M. Vinko, O. Ciricosta, B. I. Cho, K. Engelhorn, H.-K. Chung, C. R. D. Brown, T. Burian, J. Chalupský, R. W. Falcone, C. Graves, V. Hájková, A. Higginbotham, L. Juha, J. Krzywinski, H. J. Lee, M. Messerschmidt, C. D. Murphy, Y. Ping, A. Scherz, W. Schlotter, S. Toleikis, J. J. Turner, L. Vysin, T. Wang, B. Wu, U. Zastrau, D. Zhu, R. W. Lee, P. A. Heimann, B. Nagler, J. S. Wark. Creation and diagnosis of a solid-density plasma with an X-ray free-electron laser. Nature, 2012; DOI: 10.1038/nature10746

Weird world of water gets a little weirder

ScienceDaily (Nov. 9, 2011) — Strange, stranger, strangest! To the weird nature of one of the simplest chemical compounds -- the stuff so familiar that even non-scientists know its chemical formula -- add another odd twist. Scientists are reporting that good old H2O, when chilled below the freezing point, can shift into a new type of liquid.

The report appears in ACS' Journal of Physical Chemistry B.

Pradeep Kumar and H. Eugene Stanley explain that water is one weird substance, exhibiting more than 80 unusual properties, by one count, including some that scientists still struggle to understand. For example, water can exist in all three states of matter (solid, liquid,gas) at the same time. And the forces at its surface enable insects to walk on water and water to rise up from the roots into the leaves of trees and other plants.

In another strange turn, scientists have proposed that water can go from being one type of liquid into another in a so-called "liquid-liquid" phase transition, but it is impossible to test this with today's laboratory equipment because these things happen so fast. That's why Kumar and Stanley used computer simulations to check it out.

They found that when they chilled liquid water in their simulation, its propensity to conduct heat decreases, as expected for an ordinary liquid. But, when they lowered the temperature to about 54 degrees below zero Fahrenheit, the liquid water started to conduct heat even better in the simulation. Their studies suggest that below this temperature, liquid water undergoes sharp but continuous structural changes whereas the local structure of liquid becomes extremely ordered -- very much like ice. These structural changes in liquid water lead to increase of heat conduction at lower temperatures.

The researchers say that this surprising result supports the idea that water has a liquid-liquid phase transition.

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The above story is reprinted from materials provided by American Chemical Society.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Pradeep Kumar, H. Eugene Stanley. Thermal Conductivity Minimum: A New Water Anomaly. The Journal of Physical Chemistry B, 2011; 111013123335006 DOI: 10.1021/jp2051867

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World record in ultra-rapid data transmission

ScienceDaily (May 23, 2011) — Scientists at Karlsruhe Institute of Technology (KIT) have succeeded in encoding data at a rate of 26 terabits per second on a single laser beam, transmitting the data over a distance of 50 kilometers, and decoding the information successfully. This is the largest data volume ever transported on a laser beam. The process developed by KIT enables the transmission of 700 DVDs' worth of content in just one second.

The advance is reported in the journal Nature Photonics.

In this experiment, KIT scientists led by Professor Jürg Leuthold beat their own record in high-speed data transmission of 2010, when they exceeded the magic limit of 10 terabits per second -- i.e. a data rate of 10,000 billion bits per second. This success of the group is due to a new data decoding process. The opto-electric decoding method is based on initially purely optical calculation at highest data rates in order to break down the high data rate to smaller bit rates that can then be processed electrically. The initially optical reduction of the bit rates is required, as no electronic processing methods are available for a data rate of 26 terabits per second. Leuthold's team applies the so-called orthogonal frequency division multiplexing (OFDM) for record data encoding. For many years, this process has been used successfully in mobile communications, based on mathematical routines (Fast Fourier Transformation).

"The challenge was to increase the process speed not only by a factor of 1,000, but by a factor of nearly a million for data processing at 26 terabits per second," explains Leuthold, who heads the Institutes of Photonics and Quantum Electronics and Microstructure Technology at KIT. "The decisive innovative idea was optical implementation of the mathematical routine." Calculation in the optical range turned out to be not only extremely fast, but also highly energy-efficient, because energy is required for the laser and a few process steps only.

"Our result shows that physical limits are not yet exceeded even at extremely high data rates," Leuthold says, noting the constantly growing data volume on the internet. According to Leuthold, transmission of 26 terabits per second confirms that even high data rates can be handled today, while energy consumption is minimized. "A few years ago, data rates of 26 terabits per second were deemed utopian even for systems with many lasers." Leuthold adds, "and there would not have been any applications. With 26 terabits per second, it would have been possible to transmit up to 400 million telephone calls at the same time. Nobody needed this at that time. Today, the situation is different."

Video transmissions consume much Internet bandwidth and require extremely high bit rates. The need is growing constantly. In communication networks, first lines with channel data rates of 100 gigabits per second (corresponding to 0.1 terabit per second) have already been taken into operation. Research now concentrates on developing systems for transmission lines in the range of 400 Gigabits/s to 1 Tbit/s. Hence, the Karlsruhe invention is ahead of the ongoing development. Companies and scientists from all over Europe were involved in the experimental implementation of ultra-rapid data transmission at KIT. Among them were members of the staff of Agilent and Micram Deutschland, Time-Bandwidth Switzerland, Finisar Israel, and the University of Southampton in Great Britain.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Karlsruhe Institute of Technology.

Journal Reference:

D. Hillerkuss, R. Schmogrow, T. Schellinger, M. Jordan, M. Winter, G. Huber, T. Vallaitis, R. Bonk, P. Kleinow, F. Frey, M. Roeger, S. Koenig, A. Ludwig, A. Marculescu, J. Li, M. Hoh, M. Dreschmann, J. Meyer, S. Ben Ezra, N. Narkiss, B. Nebendahl, F. Parmigiani, P. Petropoulos, B. Resan, A. Oehler, K. Weingarten, T. Ellermeyer, J. Lutz, M. Moeller, M. Huebner, J. Becker, C. Koos, W. Freude, J. Leuthold. 26 Tbit s-1 line-rate super-channel transmission utilizing all-optical fast Fourier transform processing. Nature Photonics, 2011; DOI: 10.1038/NPHOTON.2011.74

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

World record in ultra-rapid data transmission

ScienceDaily (May 23, 2011) — Scientists at Karlsruhe Institute of Technology (KIT) have succeeded in encoding data at a rate of 26 terabits per second on a single laser beam, transmitting the data over a distance of 50 kilometers, and decoding the information successfully. This is the largest data volume ever transported on a laser beam. The process developed by KIT enables the transmission of 700 DVDs' worth of content in just one second.

The advance is reported in the journal Nature Photonics.

In this experiment, KIT scientists led by Professor Jürg Leuthold beat their own record in high-speed data transmission of 2010, when they exceeded the magic limit of 10 terabits per second -- i.e. a data rate of 10,000 billion bits per second. This success of the group is due to a new data decoding process. The opto-electric decoding method is based on initially purely optical calculation at highest data rates in order to break down the high data rate to smaller bit rates that can then be processed electrically. The initially optical reduction of the bit rates is required, as no electronic processing methods are available for a data rate of 26 terabits per second. Leuthold's team applies the so-called orthogonal frequency division multiplexing (OFDM) for record data encoding. For many years, this process has been used successfully in mobile communications, based on mathematical routines (Fast Fourier Transformation).

"The challenge was to increase the process speed not only by a factor of 1,000, but by a factor of nearly a million for data processing at 26 terabits per second," explains Leuthold, who heads the Institutes of Photonics and Quantum Electronics and Microstructure Technology at KIT. "The decisive innovative idea was optical implementation of the mathematical routine." Calculation in the optical range turned out to be not only extremely fast, but also highly energy-efficient, because energy is required for the laser and a few process steps only.

"Our result shows that physical limits are not yet exceeded even at extremely high data rates," Leuthold says, noting the constantly growing data volume on the internet. According to Leuthold, transmission of 26 terabits per second confirms that even high data rates can be handled today, while energy consumption is minimized. "A few years ago, data rates of 26 terabits per second were deemed utopian even for systems with many lasers." Leuthold adds, "and there would not have been any applications. With 26 terabits per second, it would have been possible to transmit up to 400 million telephone calls at the same time. Nobody needed this at that time. Today, the situation is different."

Video transmissions consume much Internet bandwidth and require extremely high bit rates. The need is growing constantly. In communication networks, first lines with channel data rates of 100 gigabits per second (corresponding to 0.1 terabit per second) have already been taken into operation. Research now concentrates on developing systems for transmission lines in the range of 400 Gigabits/s to 1 Tbit/s. Hence, the Karlsruhe invention is ahead of the ongoing development. Companies and scientists from all over Europe were involved in the experimental implementation of ultra-rapid data transmission at KIT. Among them were members of the staff of Agilent and Micram Deutschland, Time-Bandwidth Switzerland, Finisar Israel, and the University of Southampton in Great Britain.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Karlsruhe Institute of Technology.

Journal Reference:

D. Hillerkuss, R. Schmogrow, T. Schellinger, M. Jordan, M. Winter, G. Huber, T. Vallaitis, R. Bonk, P. Kleinow, F. Frey, M. Roeger, S. Koenig, A. Ludwig, A. Marculescu, J. Li, M. Hoh, M. Dreschmann, J. Meyer, S. Ben Ezra, N. Narkiss, B. Nebendahl, F. Parmigiani, P. Petropoulos, B. Resan, A. Oehler, K. Weingarten, T. Ellermeyer, J. Lutz, M. Moeller, M. Huebner, J. Becker, C. Koos, W. Freude, J. Leuthold. 26 Tbit s-1 line-rate super-channel transmission utilizing all-optical fast Fourier transform processing. Nature Photonics, 2011; DOI: 10.1038/NPHOTON.2011.74

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Large Hadron Collider sets world record beam intensity

ScienceDaily (Apr. 23, 2011) — CERN's Large Hadron Collider (LHC) has set a new world record for beam intensity at a hadron collider when it collided beams with a luminosity of 4.67×1032 cm-2s-1. This exceeds the previous world record of 4.024×1032 cm-2s-1, which was set by the US Fermi National Accelerator Laboratory’s Tevatron collider in 2010, and marks an important milestone in LHC commissioning.

“Beam intensity is key to the success of the LHC, so this is a very important step,” said CERN Director General Rolf Heuer. “Higher intensity means more data, and more data means greater discovery potential.”

Luminosity gives a measure of how many collisions are happening in a particle accelerator: the higher the luminosity, the more particles are likely to collide. When looking for rare processes, this is important. Higgs particles, for example, will be produced very rarely if they exist at all, so for a conclusive discovery or refutation of their existence, a large amount of data is required.

The current LHC run is scheduled to continue to the end of 2012. That will give the experiments time to collect enough data to fully explore the energy range accessible with 3.5 TeV per beam collisions for new physics before preparing the LHC for higher energy running. By the end of the current running period, for example, we should know whether the Higgs boson exists or not.

“There’s a great deal of excitement at CERN today,” said CERN’s Director for Research and Scientific Computing, Sergio Bertolucci, “and a tangible feeling that we’re on the threshold of new discovery.”

After two weeks of preparing the LHC for this new level of beam intensity, the machine is now moving in to a phase of continuous physics running scheduled to last until the end of the year. There will then be a short technical stop, before physics running resumes for 2012.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by CERN.

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View the original article here