Better plasma physics through grinding the computational problem to dust!The expectation by physicists for more than a decade had been that turbulence associated with ions (atoms with an electric charge) was so much larger than turbulence caused by electrons — nearly two orders of magnitude smaller — that the latter would be completely smeared out by the much larger eddies. And even if the smaller eddies survived the larger-scale disruptions, the conventional thinking went, these electron-scale whirls would be so much smaller that their effects would be negligible.
The new findings show that this conventional wisdom was wrong on both counts. The two scales of turbulence do indeed coexist, the researchers found, and they interact with each other so strongly that it’s impossible to understand their effects without including both kinds in any simulations.
Here are the two papers:
Multi-scale gyrokinetic simulation of tokamak plasmas: enhanced heat loss due to cross-scale coupling of plasma turbulence
Stabilization of electron-scale turbulence by electron density gradient in national spherical torus experiment