Subscribe free to our newsletters via your
. 24/7 Space News .




STELLAR CHEMISTRY
Livermore scientists one step closer to mimicking gamma-ray bursts
by Staff Writers
Livermore CA (SPX) May 29, 2015


The Centaurus A galaxy, at a distance of about 12 million light years from Earth, contains a gargantuan jet blasting away from a central supermassive black hole. In this image, red, green and blue show low, medium and high-energy X-rays. Photo courtesy NASA/CXC/U. Birmingham/M. Burke et al.

Using ever more energetic lasers, Lawrence Livermore researchers have produced a record high number of electron-positron pairs, opening exciting opportunities to study extreme astrophysical processes, such as black holes and gamma-ray bursts.

By performing experiments using three laser systems - Titan at Lawrence Livermore, Omega-EP at the Laboratory for Laser Energetics, and Orion at Atomic Weapons Establishment (AWE) in the United Kingdom - LLNL physicist Hui Chen and her colleagues created nearly a trillion positrons (also known as anti-matter particles). In previous experiments at the Titan laser in 2008, Chen's team had created billions of positrons.

Positrons, or "anti-electrons," are anti-particles with the same mass of an electron but with opposite charge. The generation of energetic electron-positron pairs is common in extreme astrophysical environments associated with the rapid collapse of stars and formation of black holes.

These pairs eventually radiate their energy, producing extremely bright bursts of gamma rays. Gamma-ray bursts (GRBs) are the brightest electromagnetic events known to occur in the universe and can last from ten milliseconds to several minutes. The mechanism of how these GRBs are produced is still a mystery.

In the laboratory, jets of electron-positron pairs can be generated by shining intense laser light into a gold foil. The interaction produces high-energy radiation that will traverse the material and create electron-positron pairs as it interacts with the nucleus of the gold atoms.

The ability to create a large number of positrons in a laboratory, by using energetic lasers, opens the door to several new avenues of antimatter research, including the understanding of the physics underlying extreme astrophysical phenomena such as black holes and gamma-ray bursts.

"The goal of our experiments was to understand how the flux of electron-positron pairs produced scales with laser energy," said Chen, who along with former Lawrence Fellow Frederico Fiuza (now at SLAC National Accelerator Laboratory) are the lead authors of an article are appearing in the May 18 edition of Physical Review Letters.

"We have identified the dominant physics associated with the scaling of positron yield with laser and target parameters, and we can now look at its implication for using it to study the physics relevant to gamma-ray bursts," Chen said. "The favorable scaling of electron-positron pairs with laser energy obtained in our experiments suggests that, at a laser intensity and pulse duration comparable to what is available, near-future 10 kilojoule class lasers would provide 100 times higher antimatter yield."

The team used these scaling results obtained experimentally together with first-principles simulations to model the interaction of two electron positron pairs for future laser parameters. "Our simulations show that with upcoming laser systems, we can study how these energetic pairs of matter-anti-matter convert their energy into radiation," Fiuza said. "Confirming these predictions in an experiment would be extremely exciting."

Antimatter research could reveal why more matter than antimatter survived the Big Bang at the start of the universe. There is considerable speculation as to why the observable universe is apparently almost entirely matter, whether other places are almost entirely antimatter, and what might be possible if antimatter could be harnessed. Normal matter and antimatter are thought to have been in balance in the very early universe, but due to an "asymmetry" the anti-matter decayed or was annihilated, and today very little antimatter is seen.

In future work, the researchers plan to use the National Ignition Facility to conduct laser antimatter experiments to study the physics of relativistic pair shocks in gamma-ray bursts by creating even higher fluxes of electron-positron pairs.

The research was funded by LLNL's Laboratory Directed Research and Development program and the LLNL Lawrence Fellowship. Chen and Fiuza were joined by Anthony Link, Andy Hazi, Matt Hill, David Hoarty, Steve James, Shaun Kerr, David Meyerhofer, Jason Myatt, Jaebum Park, Yasuhiko Sentoku and Jackson Williams from LLNL, AWE, University of Alberta, University of Rochester and University of Nevada, Reno.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
Lawrence Livermore National Laboratory
Stellar Chemistry, The Universe And All Within It






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








STELLAR CHEMISTRY
Strange supernova is missing link in gamma-ray burst connection
Charlottesville VA (SPX) Apr 28, 2015
Astronomers using the National Science Foundation's Very Large Array (VLA) have found a long-sought "missing link" between supernova explosions that generate gamma-ray bursts (GRBs) and those that don't. The scientists found that a stellar explosion seen in 2012 has many characteristics expected of one that generates a powerful burst of gamma rays, yet no such burst occurred. "This is a st ... read more


STELLAR CHEMISTRY
China, Russia plan joint landing on the Moon

Google Lunar X-Prize meets Yoda

NASA's LRO Moves Closer to the Lunar Surface

European Space Agency Director Wants to Set Up a Moon Base

STELLAR CHEMISTRY
Science Drives NASA's Journey to Mars

NASA Begins Testing Mars Lander for Next Mission to Red Planet

Supersonic decelerator gets a lift to prepare for launch

The Supreme Council of Parachute Experts

STELLAR CHEMISTRY
McCarthy-Smith SPACE Act passes with broad bipartisan support

Boeing Awarded First Commercial Human Spaceflight Mission

Planetary Society's LightSail has gone silent

NASA Invites Innovative Early-Stage Technology Proposals

STELLAR CHEMISTRY
China Plans First Ever Landing On The Lunar Far Side

China ranked 4th among world space powers

3D printer making Chinese space suit parts

Xinhua Insight: How China joins space club?

STELLAR CHEMISTRY
Roundworms have the Right Stuff

ISS module relocation makes way for Commercial Crew spacecraft

NASA Begins Major Reconfiguration of International Space Station

ISS Partners Adjust Spacecraft Schedule

STELLAR CHEMISTRY
Recent Proton loss to push up launch costs warns manufacturer

SpaceX cleared for US military launches

Ariane 5's second launch of 2015

Air Force Certifies SpaceX for National Security Space Missions

STELLAR CHEMISTRY
Weather forecasts for planets beyond our solar system

Astrophysicists offer proof that famous image shows forming planets

Astronomers detect drastic atmospheric change in super Earth

New exoplanet too big for its star

STELLAR CHEMISTRY
Patent for Navy small space debris tracker

MaterialsLab improves how we conduct research on Earth and in Space

Deep Web Search May Help Scientists

New computational technique advances color 3D printing process




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.