Abstract: A method for generating a high flux density neutral atom or molecule beam and a system for carrying out this method. The method comprises generating a plasma of electrons and ionized atoms or molecules, accelerating the ions, effecting charge exchange and converting moving ions to moving neutral atoms or molecules. The charged entities are filtered out thus providing a neutral atom or molecule beam. The plasma is generated by a helicon source, by a novel source here described, or by other means. The ions are accelerated by applying electric and magnetic fields perpendicular to each other.