How to create a tiny supernova, with a laser
A starry sky, romance and poetry. Yet, the sparkle of a star is the result of the most powerful and extreme nuclear reactions taking place in our universe.
For the last fifteen years recreating the heart of a star in a physics lab was only possible by adopting some of the world’s largest lasers to trigger nuclear reactions (N. McDowell, Nature 2002 416, 775).
But what about holding a “burning star” in our hand? It’s now possible, scientists affirm. As described in a paper recently published in Science Advances (http://advances.sciencemag.org/content/3/1/e1601558), a team of researchers from the Colorado State University has reproduced the extreme conditions of pressure and temperature that we find within the core of a star with small and compact ultrafast lasers. Scientists use this kind of light source, characterised by ultrashort (one millionth of one billionth of a second) but very intense pulses, to irradiate an array of aligned thin nanowires made of nichel and cobalt. By monitoring the characteristic X-rays emission from the array, they can determine the volume of heated material and how deeply energy penetrates into the sample. Experiments show that pressures even bigger than those in the centre of our Sun and local temperatures of millions of degrees can be generated increasing the irradiation intensity of the laser up to its maximum.
Studies like this, unveiling the ultra-high energy density regimes, are crucial to better understand atomic processes and light propagation in such extreme conditions, but also to make applications such as laser-drive fusion more accessible.