Food for Thought #7: donuts!
This week we have seen that the confinement of plasma can be lost via
diffusion and/or recombination. Different cross-field drifts were
omitted by saying that they can always be aligned with the vessel walls.
Reconsider the drift issue by thinking what happens if we try to take
the cylindrical vessel and
simply eliminate its end losses by turning it into a torus. Consider the
gradient and E × B drift and think out what their combined effect would
do to the confinement of electrons and ions. Initially assume only the
magnetic field that resulted from bending the cylinder into a donut and
which is toroidal now.