A representative system for providing an electric field comprises an
electrically insulated frame, guard members and endplates. The frame
incorporates a top, a bottom, opposing sides and opposing ends, with the
sides extending between the top and the bottom. Each of the ends engages
the top, the bottom and the sides. The frame defines an interior. The
guard members are suspended within the interior of the frame, with each
of the guard members being formed of metal tubing. The guard members are
spaced from each other and located along a length of the frame such that
the guard members are oriented substantially parallel to the ends of the
frame. The endplates are positioned at the ends of the frame. The frame,
guard members and endplates are operative to form an electric field
within the interior of the frame responsive to an electric potential
being applied to at least one of the endplates.