>Bruno,
>
>Could you describe your idea using a toroidal magnetic field?
>Thanks.
>
Siva
I presume you mean what I posted.
Simple magneto-plasma dynamics. electric and magnetic fields crossing each other produce a force on any conductor present across both fields. A magnetic toriod, a cylinder bent around into a loop, is a simple way to get a closed magnetic field line to be perpendicular to a desired axis along its whole length.
With loose charged particles, an electric field accelerates the particle across the desired direction of thrust, then the magnetic field turns its path.