Scientists at the SLAC National Accelerator Laboratory have achieved a significant breakthrough in materials physics by successfully measuring the temperature of atoms within hot, dense matter. Using the facility's Matter in Extreme Conditions (MEC) laser, researchers superheated a gold sample to an astonishing 19,000 Kelvin, which is over 14 times the melting point of gold. Remarkably, the gold sample maintained its solid structure despite this extreme temperature, challenging previous understandings of material limits.
This observation supports a theoretical framework suggesting that extremely rapid heating can prevent materials from expanding, thereby preserving their solid state even at temperatures far exceeding their normal melting points. The findings, published in the journal Nature, open new frontiers for exploring matter under extreme thermal conditions.
The research builds upon SLAC's extensive work in high-energy density science, utilizing advanced laser systems like the MEC laser, designed to create high-pressure and high-temperature states for scientific investigation. Previous experiments at SLAC have explored similar states of matter, including "warm dense matter," found in the cores of giant planets and stars. For instance, in 2015, SLAC researchers studied aluminum transitioning into warm dense matter, achieving pressures over 4,500 times that of Earth's deepest ocean trenches and temperatures around 20,000 Kelvin.
The technique developed by the SLAC team, led by researchers such as Bob Nagler and Thomas White, involves directly measuring the speed of atoms to determine their temperature. This method has proven invaluable for probing materials under conditions that are otherwise inaccessible. The implications of this research extend to various scientific disciplines, potentially informing our understanding of fusion energy and the fundamental properties of materials under extreme stress.