Supernova explosions recreated in the lab

A scaled supernova explosion has been recreated in the laboratory using lasers 60,000 billion times more powerful than laser pointers. An international team of researchers used the Vulcan laser at the STFC Rutherford Appleton Laboratory to recreate supernova explosions, which occur when the fuel in a star reignites or its core collapses. The aim of the research – published in Nature Physics – was to study what might cause knots and twists in detonation shock waves as seen in Cassiopeia A. Optical images reveal an irregular ‘knotty’ feature, and associated with these are intense radio and X-ray emissions. While no one knows what created these phenomena, one possibility is that the blast passes through a region filled with dense clumps or gas clouds. The team focussed three laser beams onto a carbon rod target not much thicker than a strand of hair in a low density gas-filled chamber. The enormous heat generated by the laser caused the rods to explode, creating a blast that expanded throughout the gas. A plastic grid was added to introduce turbulence into the expanding blast wave, and replicated dense gas clumps or gas clouds. “The experiment demonstrated that as the blast of the explosion passes through the grid it becomes irregular and turbulent, just like the images from Cassiopeia,” said Professor Gianluca Gregori, study leader from the University of Oxford’s Department of Physics. “The results of our experiments are significant because they help to piece together a story for the creation and development of magnetic fields in our Universe,” said Dr Nigel Woolsey from the Department of Physics at the University of York. “We have provided the first experimental proof that turbulence amplifies magnetic fields in the tenuous interstellar plasma.” The work – funded by the European Research Council, the Science and Technology Facilities Council and the US Department of Energy – also involved researchers from America, Ireland, France, Japan and Scotland. Turbulent amplification of magnetic fields in laboratory laser-produced shock waves