Researchers at Lawrence Livermore National Laboratory (LLNL) have successfully employed the National Ignition Facility’s powerful laser to investigate pressure-driven ionization, a critical process for understanding the interiors of planets and stars. The study, published in Nature, highlights how extreme compression affects material properties and electron behavior, which holds significant implications for astrophysics and nuclear fusion research. By recreating stellar conditions, the team, led by physicist Tilo Döppner, was able to observe changes in electron structure in a highly compressed beryllium sample, achieving temperatures of around two million kelvins and pressures up to three billion atmospheres.
The findings revealed that three out of four electrons in beryllium transitioned to conducting states, indicating unexpected weak elastic scattering. This research enhances the understanding of ionization mechanisms in celestial bodies, particularly in cooler stars and giant planets where pressure-driven ionization predominates over temperature-driven processes. The insights gained are crucial for advancing inertial confinement fusion experiments, guiding the development of efficient, carbon-free energy sources through laser-driven nuclear fusion. The study resulted from international collaboration involving various prestigious institutions, advancing the field of laboratory astrophysics.
