Laser experiments mimic cosmic explosions and planetary cores

News from the 2014 APS Division of Plasma Physics Meeting

2014-10-28

(Press-News.org) Researchers are finding ways to understand some of the mysteries of space without leaving earth. Using high-intensity lasers at the University of Rochester's OMEGA EP Facility focused on targets smaller than a pencil's eraser, they conducted experiments to create colliding jets of plasma knotted by plasma filaments and self-generated magnetic fields, reaching pressures a billion times higher than seen on earth.

In two related experiments, researchers used powerful lasers to recreate a tiny laboratory version of what happens at the beginning of solar flares and stellar explosions, creating something like a gigantic plasma tsunami in space. Much of what happens in those situations is related to magnetic reconnection, which can accelerate particles to high energy and is the force driving solar flares towards earth.

In a separate experiment, high-power lasers were focused on a small sphere to create intense shock waves, producing some of the highest pressures ever measured—nearly a billion atmospheres. The results provide information on how matter behaves at very high density, such as in the metallic cores of gas-giant planets and in imploding capsules for inertial fusion energy development.

LABORATORY EXPERIMENT AIMS TO IDENTIFY HOW TSUNAMIS OF PLASMA CALLED "SHOCK WAVES" FORM IN SPACE

William Fox, a researcher at the U.S. Department of Energy's Princeton Plasma Physics Laboratory, and his colleague Gennady Fiksel, of the University of Rochester, got an unexpected result when they used lasers in the Laboratory to recreate a tiny version of a gigantic plasma tsunami in space.

These tsunamis, called "shock waves," are thin areas found at the boundary between a collapsed supernova, a ball of super-hot, electrically charged gas called plasma, and the colder material around it. At that boundary is a steep, tsunami-like wall of plasma that has a turbulent magnetic field that sweeps up plasma to create the tsunami. Cosmic rays, extremely high-energy space particles, play a role in the tsunamis as they interact over and over again with the tsunami's turbulent magnetic field.

The researchers used two very powerful lasers to zap two pieces of plastic in a vacuum chamber to 10 million degrees and create two colliding plumes of extremely hot plasma.

Researchers were able to analyze what happened when the plasmas collided by using a third laser to send a beam of protons through the colliding plasma. The protons struck layers of film on the other side. The layers of film separated the various energies of protons in the beam.

Fox and Fiksel found that when the two plasmas merged they broke into clumps of long thin filaments called a "Weibel instability." It was the first time this instability was identified in a laboratory and was not predicted by the researchers themselves.

The researchers believe the Weibel instability is what causes the turbulent magnetic fields that form the tsunamis, or shock waves, in space. This magnetic field is also what pushes on and accelerates cosmic rays.

Their research could help answer questions about the origin of primordial magnetic fields that formed when galaxies were created and could help researchers understand how cosmic rays work and how plasmas are produced.

Contacts: W. Fox, PPPL, (609) 243-2354, wfox@pppl.gov G. Fiksel, LLE, (585) 275-8500, gfik@lle.rochester.edu A. Bhattacharjee, PPPL, (609) 243-3100, amitava@pppl.gov

Abstracts: BI2.00003 Astrophysical Weibel instability in counter-streaming laser-produced plasmas
10:30 AM–11:00 AM, Monday, October 27, 2014 Session BI2: Space, Astro, and Lab Astro
9:30 AM–12:30 PM, Monday, October 27, 2014
Room: Bissonet

MAGNETIC RECONNECTION IN THE LABORATORY

The solar corona already contains a strong magnetic field, so colliding plasmas there behave somewhat differently. In their next phase of research, Fiksel and Fox added a magnetic field by pulsing current through very small wires next to the experiment. They then created the two colliding plumes of plasma as they did in the earlier experiment. When the two plasmas collided it compressed and stretched the magnetic field and a tremendous amount of energy accumulated in the field like a stretched rubber band. As the magnetic field lines are pushed close together, the long lines break apart and reform like a single stretched rubber band, forming a slingshot that propels the plasma and releases the energy into the plasma, accelerating the plasma and heating it.

The experiment found that the reconnection process happens faster than theorists had previously predicted. This could help shed light on solar flares and coronal mass ejections, which also happen extremely quickly. Coronal mass ejections can trigger geomagnetic storms that can interfere with satellites and wreak havoc with cellphone service.

The laser technique the scientists are using is new in the area of high energy density plasma and allows scientists to control the magnetic field to manipulate it in various ways.

Contacts: G. Fiksel, LLE, (585) 243-2354, gfik@lle.rochester.edu W. Fox, PPPL, (609) 243-2354, wfox@pppl.gov A. Bhattacharjee, PPPL, (609) 243-3100, amitava@pppl.gov

Abstracts: TO7.00002 Strongly Driven Magnetic Reconnection in a Magnetized High-Energy-Density Plasma
9:42 AM–9:54 AM, Thursday, October 30, 2014 Session TO7: Magnetic Reconnection
9:30 AM–12:18 PM, Thursday, October 30, 2014
Room: Galerie 6

A FUSION ENERGY LASER TECHNIQUE MAY ALSO BE USEFUL FOR UNDERSTANDING PLANETARY INTERIORS

In another experiment at the OMEGA EP facility, researchers used a new laser technique to study shock ignition, a technique used in inertial confinement fusion research, which aims to create fusion energy by heating and compressing a fuel pellet.

Wolfgang Theobald, of the University of Rochester, and other researchers used lasers to zap a solid spherical target with laser beams. This blows off the outer layer of the target, forcing the inner core to implode. By using a laser beam that creates a powerful spike of energy, researchers created a shockwave that travels quickly to the core of the fuel pellet and creates intense pressures and super-hot temperatures that "ignite" the plasma, potentially creating fusion energy.

When the shock reaches the center of the target, it creates an X-ray flash, which is used to measure the exact time the shock reaches the center.

This technique not only has applications to inertial fusion, but could also lead to new high-energy-density-physics experiments that might shed light on other high-pressure conditions that exist in the universe. For example, researchers could use this experiment to study the extreme heat and high-pressure conditions at the core of planets.

Contacts: W. Theobald, (585) 273-2628, wthe@lle.rochester.edu R. Betti, (585) 275-8586, betti@lle.rochester.edu W. Seka, (585) 275-3815, seka@lle.rochester.edu R. Nora, (585) 273-2429, rnora@lle.rochester.edu

Abstracts: CI1.00002 Spherical Strong-Shock Generation for Shock-Ignition Inertial Fusion
2:30 PM–3:00 PM, Monday, October 27, 2014 Session CI1: Direct Drive, Shock and Fast Ignition, Magneto-inertial Fusion
2:00 PM–5:00 PM, Monday, October 27, 2014
Room: Acadia GO6.00005 Spherical Strong-Shock Inferences on OMEGA
2:30 PM–3:00 PM, Monday, October 27, 2014 Session Shock and Fast Ignition
9:30 AM–12:18 PM, Tuesday, October 28, 2014
Room: Galerie 3 PO4.00011 Multibeam Laser--Plasma Interactions Lead to Localized Interaction Regions
2:30 PM–3:00 PM, Monday, October 27, 2014 Session PO4: Laser Plasma Interactions
2:00 PM–5:00 PM, Wednesday, October 29, 2014
Room: Salon E

INFORMATION: END

[Attachments] See images for this press release:

Laser experiments mimic cosmic explosions and planetary cores 2

ELSE PRESS RELEASES FROM THIS DATE:

IU researchers: Blood test may help to diagnose pancreatic cancer

2014-10-28

INDIANAPOLIS -- Indiana University cancer researchers have found that a simple blood test might help diagnose pancreatic cancer, one of the most deadly forms of the disease. In research published today in the American Journal of Gastroenterology, Murray Korc, M.D., the Myles Brand Professor of Cancer Research at the Indiana University School of Medicine and a researcher at the Indiana University Melvin and Bren Simon Cancer Center, and colleagues found that several microRNAs – small RNA molecules -- circulate at high levels in the blood of pancreatic cancer patients. ...

Postcards from the plasma edge

2014-10-28

For magnetic fusion energy to fuel future power plants, scientists must find ways to control the interactions that take place between the volatile edge of the plasma and the walls that surround it in fusion facilities. Such interactions can profoundly affect conditions at the superhot core of the plasma in ways that include kicking up impurities that cool down the core and halt fusion reactions. Researchers have improved plasma performance by applying lithium coatings to the walls of fusion facilities. But a complete understanding of the mechanism behind this improvement ...

Insights into the physics of space weather that disrupts cell phones and creates Earthly havoc

2014-10-28

Each second, the sun hurls millions of tons of hot, charged plasma gas into space. This volatile "solar wind" buffets the magnetosphere, the magnetic field that surrounds the Earth, and can whip up geomagnetic storms that disrupt cell phone service, damage satellites and blackout power grids. Precise predictions of such outbursts could prompt measures to cope with them, just as forecasts here on Earth warn of approaching hurricanes and thunderstorms. Researchers throughout the United States are using laboratory experiments to uncover important physics behind this space ...

Governments should take active lead to create healthy food environments to prevent CVD

2014-10-28

Philadelphia, PA, October 28, 2014 – Canadian health organizations are calling upon governments to take a leadership role in creating healthy food environments. They say that implementing strategies that facilitate access to affordable healthy foods and beverages in places where Canadians work, live, and play could play a key role in preventing diet-related disease and health risk such as obesity and hypertension, and ultimately improve cardiovascular health, This call for action is published in the Canadian Journal of Cardiology. In 2010, unhealthy eating was identified ...

Ancient auditory illusions reflected in prehistoric art?

2014-10-28

WASHINGTON, D.C., October 28, 2014 – Some of mankind's earliest and most mysterious artistic achievements—including prehistoric cave paintings, canyon petroglyphs and megalithic structures such as Stonehenge—may have been inspired by the behaviors of sound waves being misinterpreted as "supernatural." During the 168th Meeting of the Acoustical Society of America (ASA), to be held October 27-31, 2014 at the Indianapolis Marriott Downtown Hotel, Steven J. Waller, of Rock Art Acoustics, will describe several ways virtual sound images and absorbers can ...

'Reverse engineering' materials for more efficient heating and cooling

2014-10-28

WASHINGTON, D.C., October 28, 2014 – If you've ever gone for a spin in a luxury car and felt your back being warmed or cooled by a seat-based climate control system, then you've likely experienced the benefits of a class of materials called thermoelectrics. Thermoelectric materials convert heat into electricity, and vice versa, and they have many advantages over more traditional heating and cooling systems. Recently, researchers have observed that the performance of some thermoelectric materials can be improved by combining different solid phases -- more than one ...

Calming the plasma edge: The tail that wags the dog

2014-10-28

Experiments on the DIII-D tokamak that General Atomics operates for the U.S. Department of Energy (DOE) have demonstrated the ability of lithium injections to transiently double the temperature and pressure at the edge of the plasma and delay the onset of instabilities and other transients. Researchers conducted the experiments using a lithium- injection device developed at the DOE's Princeton Plasma Physics Laboratory (PPPL). Lithium can play an important role in controlling the edge region and hence the evolution of the entire plasma. For example, researchers have ...

Remnants of tropical depression soaking Central America

2014-10-28

NASA's Terra satellite passed over Tropical Storm Hanna on Oct. 27 when it made landfall near the northern Nicaragua and southern Honduras border. On Oct. 27 at 16:00 UTC (12 p.m. EDT) the MODIS instrument aboard NASA's Terra satellite captured a visible image of Tropical Storm Hanna straddling the border between Honduras and Nicaragua. The image, created by NASA's MODIS Rapid Response Team at NASA's Goddard Space Flight Center in Greenbelt, Maryland, showed strong thunderstorms on both sides of the border, bringing heavy rainfall to those area. At 10 a.m. EDT on Oct. ...

New study uses DNA sequences to look back in time at key events in plant evolution

2014-10-28

Scientists from North America, Europe and China have published a paper in the Proceedings of the National Academy of Sciences that reveals important details about key transitions in the evolution of plant life on our planet. From strange and exotic algae, mosses, ferns, trees and flowers growing deep in steamy rainforests to the grains and vegetables we eat and the ornamental plants adorning our homes, all plant life on Earth shares over a billion years of history. "Our study generated DNA sequences from a vast number of distantly related plants, and we developed new ...

Ana's remnants raining and gusting in British Columbia, Canada

2014-10-28

NOAA's GOES-West satellite captured an image of post-tropical cyclone Ana's remnant clouds raining on British Columbia, Canada today, Oct. 28. Wind warnings along some coastal sections of British Columbia continued today as the storm moved through the region. NOAA's GOES-West satellite gathered infrared data on Ana's remnant clouds and that data was made into an image by NASA/NOAA's GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Maryland. In the image the remnant clouds resemble a frontal system. Environment Canada's Meteorological Service continued ...

Laser experiments mimic cosmic explosions and planetary cores

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: