Abstract: The invention provides methods and apparatus for extracting ions, and further for producing neutrons from the extracted ions. In an aspect, there is provided a method for extracting ions involving the following step: in a vacuum chamber applying voltages to a spark gap between two electrodes comprising coatings of a hydrocarbon, each voltage sufficient to trigger a spark discharge in the gap sufficient to dissociate the hydrocarbon and extract therefrom hydrogen ions, wherein the hydrocarbon is a nonvolatile liquid sufficiently non-viscous to flow and re-coat holes in the coatings between each spark discharge.

Abstract: An integrated field emission array for ion desorption includes an electrically conductive substrate; a dielectric layer lying over the electrically conductive substrate comprising a plurality of laterally separated cavities extending through the dielectric layer; a like plurality of conically-shaped emitter tips on posts, each emitter tip/post disposed concentrically within a laterally separated cavity and electrically contacting the substrate; and a gate electrode structure lying over the dielectric layer, including a like plurality of circular gate apertures, each gate aperture disposed concentrically above an emitter tip/post to provide a like plurality of annular gate electrodes and wherein the lower edge of each annular gate electrode proximate the like emitter tip/post is rounded. Also disclosed herein are methods for fabricating an integrated field emission array.