For HET, see the "Operation" paragraph, here.
http://en.wikipedia.org/wiki/Hall_effect_thruster
and look at a research paper, here.
http://www.me.mtu.edu/researchAreas/isp/projects.html
Being a Polywell fan, I found that paragraph very interesting. I wonder if polywell has the same unexplained factor of 1000 showing up in its transport? Or, if perhaps it is 1,000 times lessor, due to the enclosed nature of the Polywell core?Hall thrusters employ a magnetic field applied transverse to an accelerating electric field to emulate virtual accelerating electrodes. Historically, the cross-field electron mobility in HEA's has been shown to be 1,000 times greater than predicted by classical plasma theory, yet an explanation for this discrepancy is absent.