Generating Relativistic Electron-Positron Pair-Plasma Beams: A New Frontier in Laboratory Astrophysics

Researchers have successfully generated high-density relativistic electron-positron pair-plasma beams in laboratory conditions, achieving a significant breakthrough that exceeds previous pair production levels by two to three orders of magnitude. These plasmas, akin to those found around black holes and neutron stars, involve electrons and positrons moving at near-light speeds, constituting a fundamental state of matter alongside solids, liquids, and gases.

While such plasmas are common in deep space, replicating them in a lab has been a formidable challenge until now. Published in Nature Communications, the study marks the first experimental creation of these high-density plasma beams, paving the way for future experiments that could uncover fundamental insights into cosmic phenomena.

Lead author Charles Arrowsmith, from the University of Oxford and soon to join the University of Rochester’s Laboratory for Laser Energetics (LLE), underscores the significance of this achievement in advancing high-energy-density science. The experiment utilized the HiRadMat facility at CERN’s Super Proton Synchrotron (SPS) in Geneva, Switzerland, harnessing over 100 billion protons to produce quasi-neutral electron-positron pairs. These particles, released during proton collisions with atoms, mimic natural astrophysical processes, offering a new frontier in laboratory astrophysics.

“This breakthrough enables experimental investigations into the microphysics of gamma-ray bursts and blazar jets, which were previously confined to theoretical studies,” notes Arrowsmith. The team’s ability to manipulate pair beam emittance further allows controlled studies of plasma dynamics, offering insights into the behavior of cosmic phenomena like gamma-ray bursts under extreme conditions.

Collaborative efforts among institutions including LLE, University of Oxford, CERN, and others have been pivotal in achieving these advancements. The research not only enhances our understanding of astrophysical plasma dynamics but also underscores the importance of global experimental collaborations in pushing the boundaries of scientific exploration.

In addition to traditional telescopic observations and numerical simulations, laboratory-generated pair plasmas now offer a novel tool to validate theoretical models and explore the intricate details of cosmic “fireballs” influenced by interstellar environments. This interdisciplinary approach promises to deepen our understanding of the universe’s most extreme physical regimes.