Lawrence Livermore National Laboratory | 2015 May 27
[img3="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.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.
In this image, red, green and blue show low, medium and high-energy X-rays.
(Credit: NASA/CXC/U. Birmingham/M. Burke et al.)"]https://www.llnl.gov/sites/default/file ... 00px_0.jpg[/img3][hr][/hr]
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 antimatter 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 as 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. ...
Scaling the Yield of Laser-Driven Electron-Positron Jets to Laboratory Astrophysical Applications - Hui Chen et al
- Physical Review Letters 114 215001 (26 May 2015) DOI: 10.1103/PhysRevLett.114.215001
arXiv.org > physics > arXiv:1504.07148 > 27 Apr 2015