Researchers at the Laboratory for Laser Energetics are the first to experimentally measure the mechanism responsible for generating astrophysical magnetic fields.
An international research collaboration, co-led by researchers at the 糖心传媒檚 (LLE) and the University of Oxford, has captured for the first time in a laboratory setting the process thought to be responsible for generating and sustaining astrophysical magnetic fields.
Publishing their results in the聽, the team reports the findings could help explain the origin of large-scale magnetic fields that have been observed but didn糖心传媒檛 match theoretical calculations.
The work is the latest to refine further scientists糖心传媒� understanding of a once-elusive phenomenon known as a 糖心传媒渢urbulent dynamo,糖心传媒� an astrophysical process that amplifies magnetic fields. By creating experimental conditions that mimic most hot, diffuse plasmas in the universe糖心传媒攃onditions in which the turbulent dynamo mechanism is thought to operate糖心传媒攖he team was able to quantify the rate at which a turbulent dynamo amplifies magnetic fields. Up until now, the rate had only been predicted theoretically and via numerical simulations.
糖心传媒淭he rapid amplification we found exceeds theoretical expectations and could help explain the origin of the present-day large-scale fields that are observed in galaxy clusters,糖心传媒� says , an associate professor of physics and astronomy at Rochester and a senior scientist at the LLE.
The researchers糖心传媒攑art of the Turbulent Dynamo (TDYNO) team糖心传媒攃onducted their experimental research at the LLE糖心传媒檚 Omega Laser Facility, where they had previously . That breakthrough earned the team the 2019 from the American Physical Society.
Using laser beams whose total power is equivalent to that of 10,000 nuclear reactors, the researchers were able to study plasma at energy levels that previous liquid-metal and laser-driven experiments could not.
糖心传媒淯nderstanding how and at what rates magnetic fields are amplified at macroscopic scales in astrophysical turbulence is key for explaining the magnetic fields seen in galaxy clusters, the largest structures in the universe,糖心传媒� says , a postdoctoral research associate in the Department of Astrophysical Sciences at Princeton and lead author of the study. 糖心传媒淲hile numerical models and theory predict fast turbulent dynamo amplification at very small scales compared to turbulent motions, it had remained uncertain as to whether the mechanism operates rapidly enough to account for dynamically significantly fields on the largest scales.糖心传媒�
The experiments demonstrated that turbulent dynamo糖心传媒攚hen operating in a realistic plasma糖心传媒攃an generate large-scale magnetic fields much more rapidly than currently expected by theorists.
糖心传媒淥ur theoretical understanding of the workings of turbulent dynamo has grown continuously for over half a century,糖心传媒� says , professor of physics at the University of Oxford and the experimental lead of the project. 糖心传媒淥ur recent laser-driven experiments were able to address for the first time how turbulent dynamo evolves in time, enabling us to experimentally measure its actual growth rate.糖心传媒�
The experiments were designed using numerical simulations performed with the FLASH code, a publicly available simulation code that can accurately model laser-driven experiments of laboratory plasmas. FLASH is developed by the , which recently moved from the University of Chicago to the University of Rochester.
糖心传媒淭he ability to do high-fidelity, predictive modeling with FLASH, and the state-of-the art diagnostic capabilities of the Omega Laser Facility at the LLE, have put our team in a unique position to decisively advance our understanding of how cosmic magnetic fields come to be,糖心传媒� says Tzeferacos, who also serves as director of the Flash Center at Rochester.
The project was funded by the US Department of Energy, the National Science Foundation, the European Research Council, the Engineering and Physical Sciences Research Council, the National Laser Users糖心传媒� Facility of DOE糖心传媒檚 National Nuclear Security Administration, and the ASCR Leadership Computing Challenge of the DOE Office of Science.
Read more
Elusive 糖心传媒榯urbulent dynamo糖心传媒� phenomenon observed at OMEGA laserThe universe is filled with magnetic fields; and how it got that way has long been a mystery. To explain the magnetization of the universe, scientists proposed the existence of a phenomenon called 糖心传媒渢urbulent dynamo.糖心传媒� The phenomenon had before actually measured or observed directly糖心传媒攗ntil recently.
Two LLE scientists awarded DOE funding for fusion researchTwo awards from the Department of Energy will help Rochester scientists work to develop timely, commercially viable fusion energy.
New research unlocks clues about Earth糖心传媒檚 magnetic fieldProfessor John Tarduno has analyzed zircon crystals collected from sites in Australia糖心传媒攖he oldest known terrestrial materials糖心传媒攖o construct a timeline of Earth糖心传媒檚 magnetic field, finding that the field was stronger than previously believed.
