Record-High Magnetic Fields in the Lab

Record-high magnetic fields in the lab, almost a Gigagauss in magnitude, have been achieved by aiming intense laser light at a dense plasma, expanding the possibilities for laboratory re-creations of astrophysical events.

At last week’s APS Division of Plasma Physics Meeting in Orlando, researchers from Imperial College, London, and the Rutherford Appleton Lab in the UK announced evidence of super-strong magnetic fields that are hundreds of times more intense than any previous magnetic field created in an Earth laboratory and up to a billion times stronger than our planet’s natural magnetic field. Such intense magnetic fields may soon enable researchers to recreate extreme astrophysical conditions, such as the atmospheres of neutron stars and white dwarfs, in their very own laboratories.

At the Rutherford Appleton Laboratory near Oxford in the UK, researchers at the VULCAN facility aimed intense laser pulses, lasting only picoseconds (trillionths of a second), at a dense plasma. The resulting magnetic fields in the plasma were on the order of 400 Megagauss.

To determine the magnitude of the fields, the researchers made polarization measurements of high-frequency light emitted during the experiment. Recent measurements presented at the APS/DPP conference suggested that the peak magnetic field in the densest region of the plasma approaches 1 Gigagauss.

Due to technological advances peak laser intensities are likely to increase still further and consequently even higher magnetic fields may soon be possible, making it possible to put models of extreme astrophysical conditions to the test. (Poster CP1.125, November 11, contact Karl Krushelnick, Imperial College, University of London, 011-44-20-7594-7635, kmkr@ic.ac.uk; for background see Tatarakis et al., Nature, 17 January 2002)