Patent ID: 6985553

Claim:
An ion source for generating ultra-short pulses of ions, comprising: a plasma ion generator; an ion extraction system including both a plasma electrode and an extraction electrode; said plasma electrode disposed adjacent plasma produced by said plasma ion generator; said extraction electrode disposed apart from said plasma electrode; each of said plasma electrode and said extraction electrode including at least one aperture there through, said plasma electrode and said extraction electrode aligned with respect to each other so that the apertures are aligned to permit ions to pass out from said plasma ion generator and through the apertures; each aperture having diameters that are greater than a plasma sheath region thickness that is adjacent said plasma electrode, and the diameters being less than permits the plasma sheath region to wrap around the aperture through said plasma electrode to pass both ions and electrons through the aperture when a reverse voltage bias is connected to said extraction electrode to prevent ions from passing through the aperture in said extraction electrode; and, a pulse bias voltage supply connected to said extraction electrode to apply a forward bias voltage pulse having voltage pulse width, polarity and magnitude so a pulse of ions passes through the aperture in said extraction electrode that has a pulse width comparable to the voltage pulse width.