Researcher uses 100,000 degree heat to study plasma

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Using one of the greatest sources of radiation energy created by man, University of Nevada, Reno researcher and faculty member Roberto Mancini is studying ultra-high temperature and non-equilibrium plasmas to mimic what happens to matter in accretion disks around black holes.

Physics department professor and chair Mancini has received a $690,000 grant from the U.S. Department of Energy to continue his research in high energy density plasma; plasmas are considered to be the fourth state of matter. He will serve as principal investigator for a project titled"Experiments and Modeling of Photo-ionized Plasmas at Z."

"Receiving awards such as this exemplifies the academic caliber and national importance of the work in our Physics Department,"Jeff Thompson, dean of the College of Science said."We're proud of the team of researchers here working on cutting-edge science."

Mancini has been studying the atomic and radiation properties of high-energy density plasmas for more than 15 years, and this new grant will allow him to further explore what happens to matter when it is subjected to extreme conditions of temperature and radiation - similar to what happens to many astrophysical objects in the universe.

The research will enable astrophysicists to better understand what happens aroundblack holesand in active galactic nuclei. Scientists will also better understand the application of high-energy density plasmas to energy production, such as controllednuclear fusion(produced in the laboratory), and production of X-ray sources for a variety of applications.

"Using theories and tools created here at the University to design and analyze experiments, we then go to the only national facility that has the capacity to deliver the high-intensity flux of X-rays required to perform and measure these experiments,"Mancini said."We custom build instrumentation in our machine shop that meets the high standard set by the national facility so that it will fit onto the target chamber of the pulsed-power Z-machine, enabling us to conduct this unique experiment."

The pulsed-power machine at the Sandia National Laboratories in New Mexico (similar in concept but larger than the University's Nevada Terawatt Facility Zebra accelerator) is the most powerful source of X-rays on earth, Mancini said.

"We subject a very small cell - a 1-inch by½-inch cube - filled with a gas, such as neon, to this tremendous, short burst of X-ray energy,"he said."It's about 10 nanoseconds of the most intense power on earth - creating conditions of hundreds of thousands of degrees and millions of atmospheres in pressure - in the form of X-rays."

The researchers can then compare their extensive computer modeling and calculations with the measurements so they can study and explain the extreme state of matter (plasma) created during those 10 nanoseconds, which mimics the majority of matter found throughout the universe.

"We are using a unique imaging X-ray spectrometer to measure the intensity distribution of radiation as a function of wavelength, which tells us what happens with the plasma,"Mancini said. From detailed analysis of the data, Mancini can extract the plasma's density, ionization and temperature.

He said the plasma reaches extreme conditions, very unlike the low-energy plasma found in a neon light or a plasma television screen, with light 1,000 times more energetic than visible light, temperature as high as 100,000 degrees Fahrenheit, and ionization mainly driven by the action of the X-ray flux going through theplasma.

The University of Nevada, Reno Physics Department has a team of about 20 scientists, faculty and research associates working on a variety of projects in the field of High Energy DensityPlasmaPhysics Research. Mancini emphasized that having strong research programs is critical for the quality of education and training that the University can provide to students.

Source: University of Nevada, Reno

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Signs of ideal surfing conditions spotted in ocean of solar wind

(PhysOrg.com) -- Researchers at the University of Warwick have found what could be the signal of ideal wave"surfing"conditions for individual particles within the massive turbulent ocean of the solar wind. The discovery could give a new insight into just how energy is dissipated in solar system sized plasmas such as the solar wind and could provide significant clues to scientists developing fusion power which relies on plasmas.

The research, led by Khurom Kiyanai and Professor Sandra Chapman in the University of Warwick's Centre for Fusion, Space and Astrophysics, looked at data from the Cluster spacecraft quartet to obtain a comparatively"quiet"slice of the solar wind as it progressed over an hour travelling covering roughly 2,340,000 Kilometres.

In space, on these large scales, and quiet conditions, nature provides an almost perfect experiment to study turbulence which could not be done on Earth in a laboratory. This plasma energy does eventually dissipate. One obvious way of understanding how such energetic plasma could dissipate this energy would be if the particles within the plasma collided with each other. However the solar wind is an example of a"Collisionless Plasma". The individual particles within that flow are still separated by massive distances so cannot directly interact with each other. They typically collide only once or twice with anything on their journey from the Sun to the Earth.

The University of Warwick Centre for Fusion, Space and Astrophysics led team drilled down into the data on this 2,340,000 Kilometres zooming down to see how the turbulence works on these different length scales which might provide some clue as to how the plasma was able to dissipate energy.

When the researchers were able to make observations all the way down to about I kilometre they could resolve the behaviour of individual particles within the total 2,340,000 kilometres slice ofsolar wind. These regions, which held just one particle of the plasma, were themselves almost a kilometre in size. The researchers were surprised to see a new kind of turbulence on these small scales.

At this particular scale they saw that the levels of turbulence switched from being mutlifractal to single fractal pattern. This single fractal pattern turbulence appears just right to create and sustain waves that can interact with the individual particles in thesolar wind. University of Warwick astrophysicist Khurom Kiyani said:"The particles in this"collisionless plasma"may too spread out to collide with each other but this could indicate that they can, and do, interact with waves and surfing these ideal waves is what allows them to dissipate their energy."

University of Warwick astrophysicist Professor Sandra Chapman said"We have been able to drill down through a vast ocean of data covering well over two million kilometres to get an insight in to what is happening in an area about the size of a beach, and on all length scales in between. We believe we are seeing waves on that beach that are providing the ideal surfing conditions to allow plasma particles to exchange energy without collisions."

Professor Sandra Chapman also said"These results are not just an interesting piece of astrophysics as the work has been led by a 'Centre for Fusion, Space and Astrophysics' the results have also immediately come to the attention of our colleagues working to increase the stability of plasmas involved in the generation of fusion energy. Turbulence is a big problem in keeping the hot plasma confined long enough for burning to take place to generate fusion power."

More information:The research entitled Global Scale-Invariant Dissipation in CollisionlessPlasmaTurbulencehas just been published inPhysical Review Letters.

Source: University of Warwick (news:web)

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Cool plasma packs heat against biofilms

Though it looks like a tiny purple blowtorch, a pencil-sized plume of plasma on the tip of a small probe remains at room temperature as it swiftly dismantles tough bacterial colonies deep inside a human tooth. But it's not another futuristic product of George Lucas' imagination. It's the exciting work of USC School of Dentistry and Viterbi School of Engineering researchers looking for new ways to safely fight tenacious biofilm infections in patients - and it could revolutionize many facets of medicine.

Two of the study's authors are Chunqi Jiang, a research assistant professor in the Ming Hsieh Department of Electrical Engineering-Electrophysics, and Parish Sedghizadeh, assistant professor of clinical dentistry and Director of the USC Center for Biofilms."Nanosecond Pulsed Plasma Dental Probe"appears in the June 2009 issue ofPlasma Processes and Polymers.

Sedghizadeh explained that biofilms are complex colonies of bacteria suspended in a slimy matrix that grants them added protection from conventional antibiotics. Biofilms are responsible for many hard-to-fight infections in the mouth and elsewhere. But in the study, biofilms cultivated in the root canal of extracted human teeth were easily destroyed with the plasma dental probe, as evidenced by scanning electron microscope images of near-pristine tooth surfaces after plasma treatment.

Plasma, the fourth state of matter, consists of electrons, ions, and neutral species and is the most common form found in space, stars, and lightning, Jiang said. But while many natural plasmas are hot, or thermal, the probe developed for the study is a non-thermal, room temperature plasma that's safe to touch. The researchers placed temperature sensors on the extracted teeth before treatment and found that the temperature of the tooth increased for just five degrees after 10 minutes of exposure to the plasma, Jiang said.

The cooler nature of the experimental plasma comes from its pulsed power supply. Instead of employing a steady stream of energy to the probe, the pulsed power supply sends 100-nanosecond pulses of several kilovolts to the probe once every millisecond, with an average power less than 2 Watts, Jiang said.

"Atomic oxygen {a single atom of oxygen, instead of the more common O2 molecule} appears to be the antibacterial agent,"according to plasma emission spectroscopy obtained during the experiments, she said.

Sedghizadeh said the oxygen free radicals might be disrupting the cellular membranes of the biofilms in order to cause their demise and that the plasma plume's adjustable, fluid reach allowed the disinfection to occur even in the hardest-to-reach areas of the root canal.

Given that preliminary research indicates that non-thermal plasma is safe for surrounding tissues, Sedghizadeh said he was optimistic about its future dental and medical uses. Much like the spread of laser technology from research and surgical applications to routine clinical and consumer uses, plasma could change everything; especially since nonthermal plasmas don't harbor the risks of tissue burns and eye damage that lasers do, he said.

"Plasma is the future,"Sedghizadeh said."It's been used before for other sterilization purposes but not for clinical medical applications, and we hope to be the first to apply it in a clinical setting."

"We believe we're the first team to applyplasmafor biofilm disinfection in root canals,"Jiang added."This collaboration is very unique. We're attacking frontier problems, and we're happy to be broadening our fields."

Source: University of Southern California (news:web)

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Scientists Control Plasma Bullets

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(PhysOrg.com) -- On the nanoscale, things aren’t always what they seem. What first looked like a continuous plasma jet has turned out to be a train of tiny, high-velocity plasma bullets. Using a camera with an exposure time of a few nanoseconds, researchers have further investigated the plasma bullets, and have even found a way to control them.

Using a high-speed intensified charge coupled device (ICCD), Professor Mounir Laroussi and his students from the Laser&Plasma Engineering Institute at Old Dominion University in Norfolk, Virginia, has taken an up-close look at the little-known plasma bullets. Their study is published in a recent issue of theJournal of Physics D: Applied Physics.

The plasma bullets are created by a“plasma pencil,” which is a pulsed plasma source that the researchers previously developed. The plasma pencil is a hollow tube about 2.5 cm in diameter that contains two copper electrodes. To ignite the plasma, the researchers sent a gas mixture of helium and oxygen through holes in the electrodes, and applied high-voltage electric pulses between the electrodes. When the gas ignited between the electrodes, it launched a plasma plume through the hole of the outer electrode up to 5 cm into the air.

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(Left) Photograph of a plasma bullet taken with an ICCD camera, illustrating the bullet’s donut shape. (Right) An externally applied dc voltage causes the plasma plume to bend in the opposite direction. Image credit: Mericam-Bourdet, et al.

The plasma plume (which is actually a train of plasma bullets) moves at a velocity of up to 100,000 meters per second - much faster than the velocity of the gas coming out of the device, which is just 8 meters per second. Although previous research has explained that photoionization could be responsible for the high velocity, Laroussi and his students at Old Dominion have now found clues to the bullets’ original formation.

In their study, the researchers found that the length of the electrically-driven plume depends mainly on two parameters: the applied voltage between the two electrodes and the helium gas flow. Also, the average bullet velocity increases when the voltage increases. By analyzing images from the ICCD camera, the scientists also found that the bullets always become extinguished when the voltage pulse ends.

By viewing the plasma bullets at multiple angles, the researchers found another surprise: the bullet is not round, but is shaped like a donut, with a hole in the middle. Based on this shape, the researchers proposed that the plasma bullets are surface waves that travel along the interface between two media - helium and ambient air.

In addition, the researchers found that they could control the initiation time and distance of the plasma bullets by applying an external dc electric field. The applied field decreased the bullets’ average velocity and distance traveled. Also, by applying the electric field perpendicular to the axis of the plasma plume, the negatively charged plume is deflected away from the negatively charged field.

As Laroussi explained, the aim of the study was to attempt to understand the physics behind the formation and propagation of these cold plasma bullets.“There has been a lot of debate as to how these bullets propagate. So we hope that we have contributed some interesting ideas to this debate,” he toldPhysOrg.com, adding that still more work needs to be done.

Laroussi also said that the plasma bullets could be used for biomedical purposes, such as dental and wound healing applications. Teaming up with microbiologists, Laroussi has already used the tiny plasma bullets to inactivate bacteria, especially those of dental relevance such asStreptococcus mutanswhich are implicated in the onset and progression of dental caries (tooth decay).

More information:Mericam-Bourdet, N.; Laroussi, M.; Begum, A.; and Karakas, E.“Experimental investigations of plasma bullets.”J. Phys. D: Appl. Phys. 42 (2009) 055207 (7pp).

Copyright 2009 PhysOrg.com.
All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.

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Physicists produce black hole plasma in the lab

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(PhysOrg.com) -- Black holes are voracious: They devour large amounts of matter from gas clouds or stars in their neighbourhood. As the incoming"food"spirals faster and faster into the abyss, it becomes denser and denser, and heats up to temperatures of many millions of degrees Celsius. Before the matter finally disappears, it emits extraordinarily intense X-rays into space. This"last cry"originates from iron, one of the elements contained in this matter. Researchers at the Max Planck Institute for Nuclear Physics in Heidelberg have collaborated with colleagues at the Helmholtz Zentrum Berlin and used the BESSY II synchrotron X-ray source to investigate what happens in this process.

In order to understand the nature of black holes, it is best to watch them feeding. The most interesting part is just before the matter disappears behind the event horizon - that is, the distance at which the mass attraction of the black hole becomes so strong that not even light can escape. This turbulent process generates X-rays, which in turn excite variouschemical elementsin the cloud of matter to emit X-rays themselves with characteristic lines ("colours"). An analysis of the lines provides information on the density, velocity and composition of the plasmas near the event horizon.

During this process iron plays an important role. Although it is not as abundant in the universe as lighter elements - mainly hydrogen and helium - it is much better at absorbing and reemitting X-rays. Thephotonsemitted thereby also have a higher energy, respectively a shorter wavelength (a different"colour"), than that of the lighter atoms.

They therefore leave behind clear fingerprints in the rainbow of the dispersed radiation: in the spectrum they reveal themselves as strong lines. The so-called K-alpha line of iron is the final visible spectral signature of matter, its"last cry", before it disappears behind theevent horizonof a black hole, never to be seen again.

The X-rays emitted are also absorbed as they pass through the medium surrounding the black hole at larger distances. And here iron again leaves behind clear fingerprints in the spectra. The radiation ionises the atoms several times and so-called photoionisation typically strips away more than half of the 26 electrons which the iron atoms usually contain. This produces ions with positive charge states that correspond to the number of stripped electrons. The end result is highly charged ions produced not by collisions but by radiation.

It is precisely this process, the stripping of further electrons from highly charged ions by incident X-rays, which researchers at the Max Planck Institute forNuclear Physicshave reproduced in the laboratory in collaboration with colleagues at BESSY II - the Berlin synchrotron X-ray source. The heart of the experiment was the EBIT electron beam ion trap designed at the Max-Planck institute. Inside the trap, iron atoms were heated up with the aid of an intense electron beam as they would be deep inside the sun or, as in this case, in the vicinity of a black hole.

Under such conditions, iron exists, for example, as the Fe¹⁴⁺ion, ionised fourteen times as it were. The experiment proceeds as follows: A cloud of these ions, only a few centimetres long and thin as a hair, is kept suspended in an ultra-high vacuum with the help of magnetic and electric fields. X-rays from the synchrotron then impact on this cloud; the photon energy of theX-raysis selected by a"monochromator"with extreme precision and directed onto the ions as a thin, focused beam.

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The researchers use EBIT, the electron beam ion trap, to reconstruct processes in the laboratory as they occur in the matter around black holes. Image: MPI for Nuclear Physics

The spectral lines measured in this experiment can be directly and easily compared with the most recent observations made by X-ray observatories, like Chandra and XMM-Newton. It turns out that most of the theoretical calculation methods used do not predict the line positions accurately enough. This is a big problem for the astrophysicists, because without accurate knowledge of the wavelengths there is no accurate determination of the so-called Doppler effect of these lines.

The Doppler effect describes the change in frequency (energy or wavelength) of the emitted light as a function of the velocity of the source (the ions in the plasma.). Anyone who listens to the siren of a passing ambulance experiences this phenomenon: as long as the vehicle approaches, the perceived pitch of the sound is higher; as it moves away, it is lower. If the frequency in the system at rest is known (ambulance is stationary), measuring the pitch makes it possible to determine the velocity of the source - in astronomy this is the plasma.

This left the scientists puzzled over the interpretation of NGC 3783, one of the active galactic nuclei which have been under investigation for the longest time. The error bars in the frequency in a rest frame calculated with the aid of different theoretical models led to such large uncertainties in the derived velocity of the emitting plasma that reliable statements on theplasmaflows were no longer possible.

The laboratory measurements of the Heidelberg-based Max-Planck researchers have now identified one theoretical method among several model calculations that provides the most accurate predictions. They also achieved the highest spectral resolution to date in this wavelength range. It had previously not been possible to experimentally check the different theories in this energy range with such high accuracy.

The novel combination of a trap for highly charged ions and brightsynchrotronradiation sources thus represents an important step and a new approach for understanding the physics in the plasmas aroundblack holesor active galactic nuclei. The researchers expect the combination of EBIT spectroscopy and brighter and brighter X-ray sources of the third (PETRA III at DESY) and fourth generation (free-electron laser XFEL, Hamburg/Germany; LCLS, Stanford, USA; SCSS, Tsukuba, Japan) to bring fresh drive to this field.

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Scientists Generate Black Hole Radiation in the Lab

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(PhysOrg.com) -- Due to their violent nature and long distance from Earth, black holes and their surroundings are very difficult to study. Currently, the main method to observe a black hole is to use an X-ray satellite to detect the X-ray fluorescence emitted by a black hole’s companion star as the star’s material falls into the black hole. But now, scientists have developed a laser-driven method to generate a flash of brilliant Planckian X-rays in the lab that can be used to simulate the X-rays that exist near black holes. The new results contrast with the generallyaccepted explanation for the origins of these astronomical features, and may also help scientists test the complex computer codes used in X-ray astronomy.

The team of researchers, Shinsuke Fujioka, et al., from Osaka University, the Chinese Academy of Sciences, the Korea Atomic Energy Research Institute, and Shanghai Jiao Tong University, have published their study on creating Planckian X-rays in the laboratory in a recent issue ofNature Physics.

In their study, the researchers used a direct laser-driven implosion to create a hot, denseplasma. They aimed 12 intense laser beams (for a total of 3 billion watts, and carrying 4.0 kJ {kilojoules} of energy) onto a micrometer-sized spherical hollow plastic shell. When the shell’s core imploded, its temperature approached 1 keV (kiloelectronvolt), creating a hot plasma. With other adjustments to the set-up, the researchers could produce a slowly expanding, cool plasma, much like the astronomical plasma observed nearblack holes. In the laboratory-generated plasma, the researchers detected the emitted X-rays and measured their spectra.

They identified two characteristic spectral peaks that closely resemble the spectral peaks observed in the binary systems Cygnus X-3 and Vela X-1. In the model of Cygnus X-3, which consists of a black hole and a companion star, the gravitational energy of the star’s accreting material is converted into thermal energy, which is the origin of the radiation emitted by the accretion disk. The X-ray spectra of Cygnus X-3 was previously observed by an X-ray spectrometer onboard the Chandra X-ray satellite.

“Astronomers use computer simulation codes to interpret their observational data, e.g. x-ray spectra and x-ray images,” Fujioka told PhysOrg.com. “Because matter near a black hole is in extreme conditions (very hot and very massive), which was difficult to be reproduced on the Earth, astronomerscould not validate their simulation results with valid experimental data; namely, astronomers were not sure whether their simulation results and their interpretations were correct or not.

“Furthermore, astronomers cannot directly measure temperature, density, and pressure of astronomical objects; there are many unknown parameters to interpret their observations. On the other hand, we can easily measure them in the laboratory. Our experimental technique offers astronomers a test bedto validate their models and simulations by comparing them to the experimental results obtained under well-characterized extreme conditions.”

Although the X-ray spectra obtained in the lab resemble those observed astronomically, their interpretations are very different, and even contradictory. Most significantly, the first spectral peak in the two binary systems is thought to be a forbidden resonance line of helium-like silicon ions. However, as Fujioka explained, these differences could help astronomers test the computer codes used in X-ray astronomy modeling.

“X-ray spectroscopy of photoionized plasma near a black hole is an important tool to study the evolution of a black hole,” Fujioka said. “Astronomers can reproduce their observational data even with incorrect or wrong models owing to adjusting the unknown parameters. If their codes are not valid,characteristics (temperature, density, mass, pressure etc.) of the binary systems may be changed. We hope that our result improves their understanding of the birth, growth, and death of a black hole.”

More information:Shinsuke Fujioka, et al.“X-ray astronomy in the laboratory with a miniature compact object produced by laser-driven implosion.”Nature Physics, Vol. 5, November 2009.Doi:10.1038/NPHYS1402

Copyright 2009 PhysOrg.com.
All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.

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Scientists unlock the secrets of exploding plasma clouds on the sun

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Twisted"ropes"of magnetic field lines erupt from the Sun and tanglewith the Earth's magnetic field.

The Sun sporadically expels trillions of tons of million-degreehydrogen gasin explosions called coronal mass ejections (CMEs). Such clouds -- an example is shown in Figure 1 -- are enormous in size (spanning millions of miles) and are made up of magnetizedplasmagases, so hot thathydrogen atomsare ionized. CMEs are rapidly accelerated by magnetic forces to speeds of hundreds of kilometers per second to upwards of 2,000 kilometers per second in several tens of minutes. CMEs are closely related to solar flares and, when they impinge on the Earth, can trigger spectacular auroral displays. They also induce strongelectric currentsin the Earth's plasma atmosphere (i.e., themagnetosphereandionosphere), leading to outages in telecommunications and GPS systems and even the collapse of electric power grids if the disturbances are very severe.

Since the first observation of asolar flarein 1859, solar eruptions ("explosions") have attracted much attention from scientists around the world and have been studied with a succession of increasingly sophisticated international satellite missions in the past three decades. A major challenge has been that enormous and complicated plasma structures accelerating away from the Sun can only be observed remotely. As a result, it has been difficult to testtheoretical modelsto establish a correct understanding of the mechanisms that cause such eruptions. But in 2006, an international twin-satellite mission called STEREO was launched to continuously observe the erupting plasma structures from the Sun to the Earth.

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This is an artist's rendition of an expanding model CME flux rope, which is about to impinge on the Earth. The dark blue represents a weak calculated magnetic field (of the order of 15 nanotesla) while red shows a strong field (of the order of 1 gauss). One representative magnetic"field line"is illustrated. Credit: J. Chen and V. Kunkel

Now, using the data from STEREO, new research by scientists at the Naval Research Laboratory (NRL) in Washington, D.C., demonstrates for the first time that the observed motion of erupting plasma clouds driven by magnetic forces can be correctly explained by a theoretical model. The work will be presented at the 52nd Annual Meeting of the APS Plasma Physics Division.

The theory, controversial when it was first proposed in 1989 by Dr. James Chen of NRL, is based on the concept that an erupting plasma cloud is a giant"magnetic flux rope,"a rope of"twisted"magnetic field linesshaped like a partial donut. Chen and Valbona Kunkel, a doctoral student at George Mason University, have applied this model to the new STEREO data of CMEs and shown that the theoretical solutions agree with the measured trajectories of the ejected clouds within the entire field of view from the Sun to the Earth.

The position of the leading edge (LE) of a CME that erupted on December 24, 2007 were tracked by the STEREO-A spacecraft from the earliest stages of eruption to its arrival at 1 AU approximately five days later. The magnetic field and plasma parameters were measured by the STEREO-B spacecraft. The agreement between theory and data is within 1 percent of the measured position of the LE. Chen and Kunkel's results show that the theoretically predicted magnetic field and plasma properties are in excellent agreement with the measurements aboard STEREO-B. This is the first model that can replicate directly observed quantities near the Sun and the Earth as well as the actual trajectories of CMEs. Prior to STEREO, the motion of CMEs in the region corresponding to HI1 and HI2 data was not observed.

Interestingly, the basic forces acting on solar flux ropes are the same as those in laboratory plasma structures such as tokamaks developed to produce controlled fusion energy. The mechanism described by the theory is also potentially applicable to eruptions on other stars.

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Taming thermonuclear plasma with a snowflake

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Physicists working on the National Spherical Torus Experiment (NSTX) at the Princeton Plasma Physics Laboratory are now one step closer to solving one of the grand challenges of magnetic fusion research -- how to reduce the effect that the hot plasma has on fusion machine walls (or how to tame the plasma-material interface).

Some heat from the hot plasma core of a fusion energy device escapes the plasma and can interact with reactor vessel walls. This not only erodes the walls and other components, but also contaminates the plasma -- all challenges for practical fusion. One method to protect machine walls involves divertors, chambers outside the plasma into which the plasma heat exhaust (and impurities) flow. A new divertor concept, called the"snowflake,"has been shown to significantly reduce the interaction between hot plasma and the cold walls surrounding it.

Strong magnetic fields shape the hot plasma in the form of a donut in amagnetic fusionplasma reactor called a tokamak. As confined plasma particles move along magnetic field lines inside the tokamak, some particles and heat escape because of instabilities in the plasma. Surrounding the hot plasma is a colder plasma layer, the scrape-off layer, which forms the plasma-material interface. In this layer, escaped particles and heat flow along an"open"magnetic field line to a separate part of the vessel and enter a"divertor chamber."If the plasma striking the divertor surface is too hot, melting of the plasma-facing components and loss of coolant can occur. Under such undesirable conditions, the plasma-facing component lifetime would also be an issue, as they would tend to wear off too quickly.

While the conventional magnetic X-point divertor concept has existed for three decades, a very recent theoretical idea and supporting calculations by Dr. D.D. Ryutov from Lawrence Livermore National Laboratory have indicated that a novel magnetic divertor -- the"snowflake divertor"-- would have much improved heat handling characteristics for the plasma-material interface. The name is derived from the appearance ofmagnetic field linesforming this novel magnetic interface.

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This is a"snowflake"divertor -- a novel plasma-material interface is realized in the National Spherical Torus Experiment. Credit: V. Soukhanovskii, Lawrence Livermore National Laboratory

This magnetic configuration was recently realized in NSTX and fully confirmed the theoretical predictions. The snowflake divertor configuration was created by using only two or three existing magnetic coils. This achievement is an important result for future tokamak reactors that will operate with few magnetic coils. Because the snowflake divertor configuration flares the scrape-off layer at the divertor surface, the peak heat load is considerably reduced, as was confirmed by the divertor heat flux on NSTX. The plasma in the snowflake divertor, instead of heating the divertor surface on impact, radiated theheataway, cooled down and did not erode the plasma-facing components as much, thus extending their lifetime. Plasma TV images show more divertor radiation in the snowflake divertor plasmas in comparison with the standard plasmas. Importantly, the snowflake divertor did not have an impact on the high performance and confinement of the high-temperature core plasma, and even reduced the impurity contamination level of the mainplasma.

These highly encouraging results provide further support for the snowflake divertor as a viable plasma-material interface for future tokamak devices and for fusion development applications.

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Vacuum arcs spark new interest

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Whenever two pieces of metal at different voltages are brought near each other, as when an appliance is plugged into a live socket, there is a chance there will be an arc between them. Most of the arcs people see are a breakdown of the gas between the metal surfaces, but this type of breakdown can also occur in a vacuum. This vacuum breakdown, which until recently has not been well understood, has implications for applications from particle accelerators to fusion reactors.

As part of an effort to understand the maximum accelerating field in particle accelerators, scientists at Argonne National Laboratory have been modeling the processes involved in vacuum breakdown. Now, a new model of this phenomenon is beginning to reveal what is happening in these arcs, and scientists are studying a number of new phenomena associated with them.

In this new model, the breakdown arc is triggered by the electric field in thevacuumgap literally tearing the metal apart. (The same force that causes"static cling"can be very powerful for high electric fields, particularly at tiny corners, and in cracks where the fields are intensified by the local geometry of the surface.) After the metal is torn apart, the fragments should become ionized and form microscopic plasmas that are very dense and cold (for a plasma). Because of the high densities in these plasmas, the surface fields inside the arc quickly become even stronger than they were at breakdown. The arc becomes very damaging to the metal surface over a comparatively large area, eventually leaving a pit that should be visible to the naked eye.

While this model seems to be internally consistent, researchers want to use it to produce predictions that can be verified experimentally. Current research is usingmolecular dynamicsto show what happens at theatomic levelwhen the material is torn apart, plasma modeling codes to show how the plasma initially forms and what its properties are, and electrohydrodynamics to show how the surface of the arc pit is affected. While current results seem generally consistent with existing experimental measurements, more precise tests are being developed.

In principle, a better understanding of the precise causes of electrical breakdown should suggest solutions that are relevant to fusion reactors and space communications, among other things.

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Researchers pursue plasmonics and photonics technology for optical improvements

Professors Mark L. Brongersma of Stanford University and Stefan A. Maier of Imperial College London are investigating new applications for terahertz sensors.

Based on their research, these sensors could be used for improving optical sources, detectors and modulators for optical interconnections and for creating biomolecules, such as plastic explosives for the Air Force.

Brongersma's work is based on the unprecedented ability of nanometallic or plasmonic structures to concentrate light into deep-subwavelength volumes.

"Currently photodetectors, modulators and other chipscale devices are limited in their size by the fundamental laws of diffraction, but with plasmonics, we can make much more compact devices with one to two order of magnitude better performance parameters,"said Brongersma."As the size of these devices determines their operation speed and power, it's hard to make much more efficient devices."

Maier has demonstrated plasmon waveguides on a silicon platform operating in the telecom band, and under AFOSR support he has realized some of the first plasmonic devices operating at THz frequencies.

"The telecom band is important since that's where data communication is taking place by means of optical fibers and the Internet; the silicon platform is significant because most chips are made of that material,"said Maier."THz frequencies are vital for their sensing of dangerous substances, including plastic explosives and anthrax."

The study of plasmonics is bringing these scientists together as each works on fundamentals, information and biotechnology.

"Our team is working on demonstrating plasmon waveguides and cavities for a wide variety of applications spanning theelectromagnetic spectrumfrom the visible to the microwave regime,"said Maier.

Brongersma's group has worked on the basic concepts behind plasmonics-enabled light concentration and manipulation and is exploring a wide range of applications including fastercomputer chips, nanostructures synthesis, solar cells, water splitting using photoelectrochemistry, quantum optics and sensing.

Dr. Gernot Pomrenke, a program manager for the AFOSR Physics and Electronics directorate has overseen the research of these scientists for many years and Brongersma credits him with being one of the first program managers in the U.S. to realize the potential importance of plasmonics.

For their outstanding AFOSR-funded experimental and theoretical research in nano-plasmonics and nano-photonics, Brongersma and Maier were awarded the 2010 Raymond and Beverly Sackler Prize in the Physical Sciences.

"We are very excited that our fields of research have gained sufficient visibility for us to become the topics of such a prestigious prize, and we are excited and honored to share the prize equally,"said Brongersma.

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Scientists Use Atomic Physics Codes to Study Coronal Mass Ejections

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(PhysOrg.com) -- Giant eruptions of ionized gas, or plasma, from the Sun called coronal mass ejections {CMEs} produce solar energetic particles that cause spacecraft anomalies and communication interruptions, and can have significant adverse effects on Global Positioning Systems. Scientists at the Naval Research Laboratory's Space Science Division are studying CMEs in an effort to better understand and predict their impact on instrumentation.

The composition of CMEs can tell us much about how they erupt and propagate through interplanetary space. The NRL research team is now coupling computer codes that compute the evolution of CME ion charge states (elements such as Carbon or Iron with different numbers of electrons removed) to the output of numerical magnetohydrodynamic simulations of CME dynamics.

The ionization evolution code used in the simulations, developed by Martin Laming and Cara Rakowski of the Space Science Division, incorporates the latest and most accurate theoretical data for ionization and recombination (removal and attaching electrons to an element) of all ions up to Nickel in the periodic table.

Of the abundant elements in the solar atmosphere, Iron {Fe} is highly useful to study, because it has many charge states to evolve through. As a simulated CME eruption proceeds, plasma heating beginning at a heliocentric distance of about four solar radii increases the charge states of the ions in theplasma.

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Figure 2. View of CME eruption simulation performed by Ben Lynch of the Space Sciences Laboratory at UC Berkeley. The white diamond marks the plasma element for which the ionization balance is computed above. At three solar radii it would have been moving through the current sheet connecting the plasmoid to the Sun, where plasma heating occurs by reconnection.

The final simulated Fe charge state distribution exhibits a characteristic"two-peaked"structure that is commonly detected in CME observational data for Fe, with charge states around Fe¹⁶⁺and Fe¹¹⁺dominant, which indicates that basic features of the new coupled numerical model are correct.

Laming explains that a research goal of this work is to produce quantitative inferences about the energy released, and estimate for example the energy going into solar energetic particles that constitute a major radiation hazard for space borne instrumentation. Such inferences are only feasible because the energy required to produce specific ions is understood from atomic physics.

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How do free electrons originate?

Scientists at Max Planck Institute of Plasma Physics (IPP) in Garching and Greifswald and Fritz Haber Institute in Berlin, Germany, have discovered a new way in which high-energy radiation in water can release slow electrons. Their results have now been published in the renowned journal,<i>Nature Physics</i>. Free electrons play a major role in chemical processes. In particular, they might be responsible for causing radiation damage in organic tissue.

When ionising radiation impinges on matter, large quantities of slow electrons are released. It was previously assumed that these electrons are ejected by the high-energy radiation from the electron sheath of the particle hit - say, a water molecule. In their experiment the Berlin scientists bombarded water clusters in the form of tiny ice pellets with soft X-radiation from the BESSY storage ring for synchrotron radiation. As expected, they detected the slow electrons already known. In addition, however, they discovered a new process: Two adjacent water molecules work together and thus enhance the yield of slow electrons.

First the energy of the X-radiation is absorbed in the material: A water molecule is then ionised and releases an electron. But this electron does not absorb all of the energy of the impinging X-ray photon. A residue remains stored in the ion left behind and causes another electron to be released just very few femtoseconds later. (Afemtosecondis a millionth of a billionth of a second. For example, the electrons in a chemical process take a few femtoseconds to get re-arranged.) This process is known as autoionisation, i. e. the molecule ionises itself.

The Max Planck scientists have now discovered that two adjacent water molecules can work together in such an autoionisation process. Working in conjunction, they achieve a state that is more favourable energy-wise when each of them releases an electron. What happens is that the molecular ion produced first transfers its excess energy to a second molecule, which then releases an electron of its own. This energy transfer even functions through empty space, no chemical bonding of the two molecules being necessary.

This discovery did not really come as a surprise. More than ten years ago theoreticians at the University of Heidelberg around Lorenz Cederbaum had predicted this"Intermolecular Coulombic Decay". It had already been observed in frozen rare gases. Identifying it beyond doubt now in water called for a sophisticated experimentation technique by which the two electrons produced are identified as a pair.

By demonstrating that the process is possible in water - thus presumably in organic tissue as well - the IPP scientists might now be able to help clarify the cause ofradiation damage.“Slow electrons released in an organism may have fatal consequences for biologically relevant molecules,” states Uwe Hergenhahn from the Berlin IPP group at BESSY: “It was just a few years ago that it was found that deposition of such electrons can cut organic molecules in two like a pair of scissors. Very little is known as yet about how this and other processes at the molecular level give rise to radiation damage. What is clear, though, is that this constitutes an important field of research.” Intermolecular Coulomb decay is also important for other chemical processes: The paired actionof a water molecule and a substance dissolved in the water could clarify how dissolving processes function at the molecular level.

The results of the IPP scientists were recently published in the renowned journal,Nature Physics. The same issue also features a complementary experiment in which a research group at the University of Frankfurt observed intermolecular Coulombic decay in the tiniest possible water cluster conceivable, comprising just twowater molecules.

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Getting to know the sun advances fusion research

Researchers at the Princeton Plasma Physics Laboratory have successfully used Coaxial Helicity Injection (CHI) to generate plasma current and couple it to a conventional current generation method at the National Spherical Torus Experiment (NSTX) fusion experiment. After coupling, the combined process generated 1 million amperes of current using 40 percent less energy than needed to generate this current using the conventional means by itself, thus demonstrating that a high-quality initial magnetic configuration was produced by CHI.

Plasma confinement devices based on the tokamak concept rely on a solenoid through the center of the device to generate the initial current. Because the solenoid is used as an electrical transformer, its pulse length is limited in duration and it cannot sustain the initial current indefinitely in a steady-state reactor. Thus a method to eliminate the solenoid would remove a large component from the center of the tokamak, making the device simpler and less expensive. This allows the freed space in the center to be used in optimizing the device, making the tokamak more efficient by producing a magnetic configuration similar to that in a spherical tokamak.

CHI generates plasma currents by producing amagnetic bubbleusing magnetic reconnection. This is analogous to producing a soap bubble by blowing air through a ring dipped in soap solution. During CHI, currents are driven along magnetic filaments so that the resultingmagnetic forcesovercome the magnetic filament tension and cause the magnetic surface to stretch into the tokamak vessel. The figure below is a sequence of visible camera images that shows the bubble being generated on the lower part of NSTX and expanding to fill the entire vessel volume.Solar flareson the surface of the sun erupt and also reconnect through the process ofmagnetic reconnection.

After this bubble has been created in NSTX it carries a current of more than 250 thousand amperes, which is 100 times more than the seed current used to initiate the discharge. As a result of this very high current multiplication factor the process is efficient and consumes less than one Joule of stored energy to generate 10 amperes of current. The CHI method has been studied in the smaller Helicity Injected Tokamak (HIT-II) at the University of Washington in which the current multiplication factor was six. NSTX is thirty times larger in volume, and researchers have found the process to be much more efficient on NSTX, indicating that the method scales well to future larger machines.

In a steady-state reactor this initial current would be sustained by injecting high-energy particles. These particles would produce more current if the plasma density is small. For easier control of high-performance plasma, it is necessary that the distribution of the plasma current is preferentially driven near the outer edges of the magnetic configuration. The recent CHI discharges on NSTX have also generated the start-up current with these desired features needed for steady-state operation.

These exciting new results, combined with the capability of CHI to produce a large amount of current at high efficiency in larger machines, bodes well for the application of this new method in future tokamaks and spherical tokamaks. These results will be presented in an invited talk at the American Physical Society, Division ofPlasmaPhysics 52nd annual meeting on November 8-12 in Chicago.

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Jetting into the Quark-Gluon Plasma

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After the quark-gluon plasma filled the universe for a few millionths of a second after the big bang, it was over 13 billion years until experimenters managed to recreate the extraordinarily hot, dense medium on Earth. The JET Collaboration, a team from six universities and three national laboratories led by Berkeley Lab’s Nuclear Science Division, is now developing a new and highly detailed theoretical picture of this unique state of the early universe.

The Department of Energy’s Office ofNuclear Physicsrecently named Berkeley Lab’s Nuclear Science Division to lead a nine-institution collaboration investigating the “Quantitative Jet and Electromagnetic Tomography of Extreme Phases of Matter in Heavy-Ion Collisions” - JET, for short.

The JET Collaboration is a five-year theoretical effort to understand the properties of the extraordinarily hot and dense state of matter known as the quark-gluonplasma. The quark-gluon plasma filled the Universe a few millionths of a second after the big bang but instantly vanished, condensing into the protons andneutronsand other particles from which the present Universe descended.

Some 13.7 billion years later, experimenters recreated the quark-gluon plasma on Earth, using the Relativistic HeavyIon Collider(RHIC) at Brookhaven National Laboratory. The first heavy-ion collisions occurred at RHIC in 2000, but confirming the occurence of the quark-gluon plasma in these events took several more years of data collection and analysis.

Freeing the quarks

Quarkscome in three different“colors,” and it takes three quarks to build a proton or a neutron; as carriers of the color charge, an aspect of the strong nuclear interaction, gluons literally glue the quarks together.

Under ordinary conditions neither quarks nor gluons are ever free. The farther apart they get, the stronger the force between them. Because mass and energy are interchangeable, as described by Einstein’s E=Mc2, eventually the energy that would be needed to separate them goes into creating new bound quarks instead.

RHIC was designed to collide heavy nuclei (as heavy as gold, whose nucleus consists of 79 protons and 118 neutrons) at energies so high that during the near-light-speed collisions, conditions cease to be anything like ordinary. Dense, hot fireballs blossom in the collisions, forming a plasma in which neither quarks nor gluons are bound together; instead they move independently with almost complete freedom.

The RHIC results held some surprises. Unlike more familiar plasmas in which electrically charged particles are separated from one another, the quark-gluon plasma consists of color charges. The quark-gluon plasma produced at RHIC turned out to be more like a liquid than a gas.

“One of the main discoveries at RHIC is that the quark-gluon plasma produced in heavy-ion collisions behaves as a perfect fluid with very small viscosity,” says Xin-Nian Wang, a senior scientist in the Nuclear Theory Group in Berkeley Lab’s Nuclear Science Division (NSD). Wang is the co-spokesperson and project director of the JET Collaboration.

Perfect fluidity arises because the plasma’s constituents are strongly coupled, causing their collective flow. And the quark-gluon plasma flows freely, like low-viscosity motor oil in a hot engine - much more freely, in fact, Wang says, because its specific shear viscosity is “an order of magnitude less than that of water.”

Another RHIC discovery was the predicted but never-before-seen“jet quenching.” When individual particles collide in a vacuum - as when protons collide in CERN’s Large Hadron Collider, for example - the debris often flies out in a pair of jets; particles like pions or kaons detected on one side of the detector are correlated, in terms of total momentum and energy, with particles detected on the opposite side.

“But when heavy ions collide, they produce an incredibly dense medium, 30 to 50 times as dense as an ordinary nucleus,” Wang says. “The farther a jet of particles has to push through this strongly interacting nuclear matter, the more energy it loses. One jet from the back-to-back pair may not escape the fireball at all.”

The energy of the trapped jet has to go somewhere. The energetic particles that are initially produced decay to softer ones which further interact with the medium, producing shock waves in the fluid. As with the sonic boom from a jet plane“breaking the sound barrier” - flying faster than the speed of sound in air - the shock wave from a jet swallowed by the quark-gluon plasma could be used to measure the velocity of sound in the plasma.

The debris from heavy-ion collisions indicates that free quarks and gluons recombine into hadrons (which include pions and kaons made of two quarks and protons and neutrons made of three quarks) while the plasma is cooling; this also affects how the jets propagate.

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Protons and neutrons (upper left) are made of up and down quarks bound by color charges carried by gluons. But in a hot, dense quark-gluon plasma (right), quarks and gluons are unbound and free to move independently.

Probing the plasma

Jets are called“hard probes.” Although by nature strongly interacting, they are moving so fast and with so much energy that their interaction with the surrounding free quarks and gluons in the plasma is actually relatively weak. A jet’s ability to transfer energy and momentum to the medium as it moves through the fireball is known as the jet transport coefficient (JTC), which is related to the plasma’s viscosity: the smaller the viscosity - and the viscosity of the quark-gluon plasma is very small indeed - the larger the JTC.

It’s not just the degree of jet quenching, a figure that emerges in the data from millions of collision events, but the orientation, directionality, and composition of the jets that have much to tell about what’s inside the fireball, and thus about the properties of the quark-gluon plasma.

Another kind of probe, an electromagnetic probe, is so weak there is virtually no interaction with the medium at all. Electromagnetic probes appear when a jet of particles in one direction is balanced not by another jet but by a single, very energetic photon.

The task of the JET Collaboration is to use the existing evidence from the RHIC results to calculate in detail what’s really going on inside the strongly interacting quark-gluon plasma - the kind of three-dimensional picture of an otherwise invisible interior that’s called tomography, as in computed axial tomography, the familiar CAT scan.

Three kinds of phenomena are critical to the completion of the task: collectivity, to determine the viscosity of the medium; jets, to determine the jet transport coefficient; and the excitation of the medium, to determine the velocity of sound within it.

More than one kind of calculation will be required. Different assumptions and different codes must be used to model different kinds of interactions and different properties, and the results don’t always agree. The JET Collaboration includes representatives from major institutions that have made significant contributions to the study of the hot, dense matter in heavy-ion collisions, often approaching the question from different points of view. Working together, a consistent picture of thequark-gluon plasma will emerge.

Once the calculations are complete, having taken into account the entire energy spectrum of particles emerging from millions of evanescent fireballs, the new theoretical picture of this unique state of theearly universewill be tested against observations at the newly upgraded RHIC and at the ALICE experiment at the Large Hadron Collider (LHC) at CERN. (The LHC collidesprotonsfor most of the year, but for a month each year it will collide heavy ions in the form of lead nuclei.)

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Jets are"hard probes"of the quark-gluon plasma. Especially revealing information can be derived when one of the pair of jets is unable to escape the hot, dense medium.

The JET Collaboration

In the JET Collaboration, Berkeley Lab will be represented by theorists Wang, Volker Koch, and Feng Yuan. The Lab’s leadership in both the theory of the quark-gluon plasma and in its experimental exploration through the Relativistic Nuclear Collision (RNC) group uniquely positions the Lab to head the Collaboration.

The idea of jet quenching was first proposed for proton-proton collisions in the early 1980s, by James Daniel Bjorken of the Stanford Linear Accelerator Center. The theory linking jet quenching to the quark-gluon plasma in heavy-ion collisions was later developed by Xin-Nian Wang and Miklos Gyulassy; Gyulassy was with Berkeley Lab at the time and is now at Columbia University, where he is a member of the JET Collaboration.

On the experimental side, the heart of the STAR experiment at RHIC is a time projection chamber built at Berkeley Lab and invented here by David Nygren of the Physics Division; STAR is one of many time projection chambers around the world, including the heart of the ALICE experiment at the LHC. The electromagnetic calorimeter, EMCal, which will trigger the recording of interesting jet events in ALICE, is being constructed by an international team led by U.S. members of ALICE, with project management by Berkeley Lab’s Peter Jacobs of NSD and Joseph Rasson of Engineering.

Other DOE labs participating in the JET Collaboration are Lawrence Livermore, represented by Ramona Vogt, and Los Alamos, represented by Ivan Vitev. In addition to Columbia University, represented by Gyulassy, other universities include Duke, represented by Steffen Bass and Berndt Mueller, the JET Collaboration’s co-spokesperson, plus Charles Gale and Sangyong Jeon of McGill, Ulrich Heinz and Abhijit Majumder of Ohio State, Denes Molnar of Purdue, and Rainer Fries and Che-Ming Ko of Texas A&M.

JET is one of three topical collaborations established by DOE’s Office of Nuclear Physics. Over a period of five years, with a budget of $2.5 million, the JET Collaboration will not only develop theory but work closely with experimentalists, train students and postdoctoral fellows, and form associations with a wide range of researchers in the nuclear sciencecommunity at institutions in the U.S. and abroad.

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Going plasmonic in search of faster computing, communications

The pioneering devices, which are expected to lead to commercial applications within the next decade, make use of electron plasma oscillation to transmit optical and electronic signals along the same metal circuitry via waves of surface plasmon polaritons. In contrast, signals in electronic circuits are transmitted by electrons, while photons are used to carry data in optical systems.
As an emerging nano-scale technology that is often referred to as“light on a wire,” plasmonics, as the field of research is known, shares the advantages of fibre optics, including ultra-high-speed data transfer, with the benefits of electronic components, particularly their small size. The technology holds the promise of all-optical computer chips operating atultra-fast speeds, faster communications and a vast new range of sensing devices.
“For the last five years or so it has been possible to build an optical computer chip, but with all-optical components it would have to measure something like half a metre by half a metre and would consume enormous power. With plasmonics, we can make the circuitry small enough to fit in a normal PCwhile maintaining optical speeds,” explains Anatoly Zayats, a researcher at The Queen's University of Belfast in the United Kingdom.
Until now, however, plasmonic devices had been let down by the short distance over which plasmons could transmit data signals - a problem that Zayats and his team solved in the EU-funded Plasmocom project.
Pushing plasmons further
Plasmonic data transmission functions on the basis of oscillations in the electron density at the boundary of two materials: a dielectic (non-conductive) plasma or polymer and ametal surface. By exciting the electrons with light it is possible to propagate high-frequency waves of plasmons along a metal wire or waveguide, thus transmitting a data signal. However, in many cases the signal dissipates after only a few micrometres - far too short to interconnect two computer chips, for example.
The Plasmocom team took a novel approach, developing what they called dielectric-loaded surface plasmon polariton waveguides (DLSPPW). By patterning a layer of various polymer (polymethyl methacrylate) dielectic onto gold film supported by a glass substrate, they were able to achieve waveguides that were only 500 nanometres in size while extending the signal propagation.

Using this approach, the researchers built a variety of plasmonic devices, including low-loss S bends, Y-splitters and a waveguide ring resonator, a crucial part of the add-drop multiplexers (ADM) in optical networks that combine and separate several streams of data into a single signal and vice versa.
While current commercial optical ring resonators have a radius of up to 300 micrometres, the plasmonic demonstrator built by the Plasmocom team measured just five micrometres.
“The devices performed almost 100 percent as we had modelled them, and showed very good characteristics overall,” Zayats says. “Such devices need to keep getting smaller if we are to continue to see performance gains in new applications,” he adds.
Close to market technology
Crucially, the Plasmocom technology can create plasmonic devices using existing commercial lithography techniques.
“Other groups of researchers have achieved similar or better propagation or smaller device sizes but the processes they have used are often extremely complex and would be difficult to replicate at an industrial scale,” Zayats explains. “Our technology may not be the smallest... but it is closer to market.”
French chipmaker and project partner Silios Technologies is currently drawing up a commercialisation plan, which may involve either producing plasmonic components itself or licensing the Plasmocom technique to one of the big players in the industry.
Zayats notes that interest in the team’s work has been extensive within both academia and industry, evidenced by the success of a workshop in June in Amsterdam attended by representatives of several photonics and electronics firms, including NEC and Panasonic.
“I think that we will start to see this technology make its way into commercial applications over the next five to ten years,” Zayats says. “A key breakthrough will be using plasmonics for inter-chip communication, making it possible to transmit data between one or more chips at optical speeds and eliminating a major bottleneck to faster computers.”
More information:http://www.plasmocom.org/
Provided byICT Results


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