Extreme conditions prevail inside stars and planets. The pressure reaches many millions of bars and it can be several million degrees hot. Such states of matter can only be generated in the laboratory for a short time and in a tiny volume. Until now, this has required the most powerful lasers in the world, such as those at the National Ignition Facility (NIF) in California. A research team led by the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), together with partners, has now succeeded in producing and observing such extreme conditions with a much smaller laser.
The research team used a laser to bombard a thin copper wire just 25 µm thick and then used the powerful X-ray flashes of the European XFEL to observe what was happening inside the wire. The measurements showed that the density of the copper in the center of the wire was briefly eight to nine times higher than in "normal" cold copper. Computer simulations suggested that a pressure of 800 megabars was reached. This corresponds to 800 million times the atmospheric pressure and 200 times the pressure inside the Earth." The temperature reached was also enormous by earthly standards: 100,000 °C. These are conditions that come close to those in the corona of a white dwarf star. However, it would also be possible to achieve conditions such as those found in the interior of giant gas planets.
The new measuring method should not only be useful for astrophysics, but also for fusion research.
