A couple of articles I came across, both from the Univ. of Illinois (I think). They discuss gridded IEC designs for thruster design or even power production. Not Polywells, but they discuss such things as creating useful ion beams for thrust (or potentially power conversion) with both electrostatic means and magnetic means.
http://www.avrc.com/presentations/iecfu ... er_v_8.pdf
http://159.226.231.79/pf/cdr_pdfs/index ... 1240_1.pdf
Dan Tibbets