PHYSICS · Multi-part · Fermi University Physics · Plasma Physics · The plasma state and single-particle motion · Laboratory, industrial and space plasmas
Plasma Physics, Ch One particle in given fields: gyration and the guiding-centre drifts
Problem
A 5.0keV electron moves in the Earth's magnetotail, where the field is B=5.0nT and the current sheet within which the field reverses has a half-thickness L=500km.
((a)) Compute the electron's Larmor radius, treating its motion as non-relativistic.
((b)) Compute the ratio rL/L and decide whether the guiding-centre ordering rL/L≪1 holds here.