Laser Creates Star-Like Plasma in Metal Within Trillionths of a Second
Scientists capture unprecedented view of copper atoms losing and regaining electrons during extreme ionization process using cutting-edge laser technology.
Researchers at Helmholtz-Zentrum Dresden-Rossendorf have achieved a groundbreaking visualization of how matter transforms into plasma under extreme laser conditions, capturing the split-second chaos that unfolds when powerful laser flashes create superheated, star-like conditions in metal. The team combined two advanced laser systems to track how copper atoms lose and regain electrons in trillionths of a second, providing unprecedented insight into fundamental physics processes.
The experiment utilized both an X-ray free-electron laser and the high-intensity optical laser ReLaX at the HED-HiBEF experimental station at the European XFEL in Schenefeld near Hamburg. These cutting-edge instruments delivered laser pulses lasting just 25 and 30 femtoseconds respectively, allowing researchers to observe ionization processes that occur within picoseconds. The achievement represents a significant advancement in understanding how high-energy lasers interact with matter under extreme conditions.
During the experiment, researchers directed intense laser bursts at copper wire approximately one-seventh the thickness of a human hair, delivering energy reaching about 250 trillion megawatts per square centimeter. These extreme conditions, typically found only near neutron stars or during gamma-ray bursts, instantly vaporized the copper wire and produced plasma with temperatures of several million degrees. The copper atoms lost multiple electrons, becoming highly charged Cu²²⁺ ions.
Using a pump-probe approach, the team employed a second laser pulse to examine the plasma as it formed and evolved. This probe pulse, generated by the European XFEL, emitted intense hard X-rays specifically tuned to interact with the highly charged copper ions. By recording how these X-rays interacted with the plasma, scientists captured a sequence of snapshots revealing the temporal development of the ionization process.
Dr. Lingen Huang, head of experimentation in HZDR's Division of High-Energy Density, explained that the work provides new methods for improving diagnostics in laser fusion research while offering fundamental insights into extreme physics. The research demonstrates how modern laser technology can recreate and study cosmic-level phenomena in laboratory settings, potentially advancing both our understanding of stellar physics and practical applications in fusion energy development.
