I'd experiments 6 years with specific high voltage thrusters, moven without ion-wind. As resoult, project enclosen thrusters with extra high thrust, possible to fly together with power supply.
Thrust became by flow of zero point energy's mass, as reaction. You can find theory and practical on my links:

http://thruster.groupkos.com/finale.html
http://www.fw.hu/bmiklos2000/finale.html

Regards:
Miklos Borbas