Cosmos
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By Cosmos
Unlocking the secrets of black holes is one step closer with researchers generating a rotating ring of plasma in the lab, which will enable more realistic studies of plasma accretion disks.
Accretion discs are the hot, thin rotating discs formed by matter slowly spiralling towards a black hole.
A team at Imperial College London used their Mega Ampere Generator for Plasma Implosion Experiments (MAGPIE) machine to spin plasma in a more accurate representation of accretion disks. Details of the experiment are published in the journal Physical Review Letters and are also being widely published by specialist physics journals.
The lab plasma produced a jet perpendicular to the disk, as real black holes do.
Plasma is the word given to the fourth state of matter (solid, liquid, gas, plasma). A plasma is so hot that some or all its constituent atoms are split up into electrons and ions, which can move independently of each other and which can be strongly influenced by electrostatic and electromagnetic fields and forces.
The Imperial College experiment could provide a platform for testing theories describing the evolution of astrophysical disks.
In a report about the science, Physics Magazine corresponding editor Rachel Berkowitz says researchers placed eight plasma sources in a circle and aimed all of their outputs slightly off centre.
“This pinwheel geometry produced a rotating plasma ring at the centre, far from the walls,” she wrote.
“The plasma also expanded upward – perpendicular to the ring – in a jet reminiscent of the powerful outflows seen in real black holes, where gravity is a dominant force.”
“The colliding plasma creates something that resembles gravity, so we can study the physics of accretion disks in the absence of actual gravity,” says Vicente Valenzuela-Villaseca who was involved in the research as an Imperial College graduate student, but who is now at Princeton University, US.
Berkowitz says the 6mm-diameter ring lasted only about 210 nanoseconds because the sources that created it were short-lived.
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