Table-top experiment to reveal star secrets
doi:10.1038/nindia.2017.76 Published online 5 July 2017
Scientists have been able to recreate solar turbulence on a table top, opening up the possibility of studying astrophysical phenomena, such as the evolution of stars, in a lab.
Much of the Universe consists of highly ionized and extremely hot gas (known as plasma) swirling at incredible speeds. The motion of these charged species — negatively charged, light electrons and positive heavy ions making up the plasma — generates a magnetic field.
The randomness of magnetic fields generated due to fluctuations in the velocity and pressure of the swirling charged particles mimics in plasmas the kind of turbulence one sees in ordinary fluids. Until now, turbulent magnetic field dynamics that explain astrophysical phenomena could be obtained only through observations via telescopes and satellites.
Now, a team of scientists from the Tata Institute of Fundamental Research in Mumbai and Institute of Plasma Research in Gandhinagar (both in India) and at the Instituto Superior Tecnico, Universidade de Lisboa in Portugal have created such magnetic turbulence in the lab. They used a high intensity ultrashort laser pulse to excite a hot, dense plasma on a solid surface and studied the extremely fast evolution of the giant magnetic field generated by the plasma dynamics.
"Our lab observations have an uncanny resemblance to the satellite data on the magnetic field spectra measured for turbulent astrophysical plasmas in the solar wind," the authors report. "This demonstrates the potential of small-scale, table-top laboratory experiments for investigating turbulence in astrophysical environments."
1. Chatterjee, G. et al. Magnetic turbulence in a table-top laser-plasma relevant to astrophysical scenarios. Nat. Commun. 8, 15970 (2017) doi: 10.1038/ncomms15970