Method for the production of an ion beam having a large cross-sectional area

Claim 1

The method of increasing the cross-sectional area of a parallel ion beam, the steps of causing a first double deflection of a parallel incident ion beam in a plane X by first deflecting the ions away from the axis of the incident ion beam and then deflecting the ions back toward said axis such that the resulting ion beam is parallel to the incident ion beam, and causing a second double deflection of the ion beam in a plane Y which is perpendicular to the plane X by first deflecting the ions away from the axis of the incident ion beam and then deflecting the ions back towards said axis such that the resulting ion beam is parallel to the incident ion beam, said two double deflections being caused, respectively, by at least two alternating electric fields having different periods, said fields being parallel to said planes X and Y, respectively, and perpendicular to the direction of the incident ion beam, said double deflection in both X and Y planes producing a parallel ion beam of increased cross-sectional area from that of said incident ion beam, at least one of said two double deflections being caused by the application of alternating current potential to one electrode of two spaced electrodes between which the ion beam passes while maintaining the other of the two spaced electrodes at ground potential to thereby produce an alternating electric field having a period substantially equal to k times the transit time during which an ion undergoes said double deflection, wherein k is a whole number, and the maximum radial distance rmax of an ion subjected to a double deflection with respect to the center of said incident ion beam being: rmax (1/16) (Vmax)/(Va.d) L2/k wherein vmax is the maximum potential difference established between said two electrodes spaced at a distance d from each other, L is the length of said electrode in the direction of said incident ion beam and Va is the ion acceleration voltage in said direction.

Claim 2

The method of increasing the cross-sectional area of a parallel ion beam, the steps of causing a first double deflection of a parallel incident ion beam in a plane X by first deflecting the ions away from the axis of the incident ion beam and then deflecting the ions back toward said axis such that the resulting ion beam is parallel to the incident ion beam, and causing a second double deflection of the ion beam in a plane Y which is perpendicular to the plane X by first deflecting the ions away from the axis of the incident ion beam and then deflecting the ions back towards said axis such that the resulting ion beam is parallel to the incident ion beam, said two double deflections being caused, respectively, by at least two alternating electric fields having different periods, said fields being parallel to said planes X and Y, respectively, and perpendicular to the direction of the incident ion beam, said double deflection in both X and Y planes producing a parallel ion beam of increased cross-sectional area from that of said incident ion beam, at least one of said two double deflections being caused by the application of alternating current potential to one electrode of two spaced electrodes between which the ion beam passes while maintaining the other of the two spaced electrodes at ground potential to thereby produce an alternating electric field having a period substantially equal to k times the transit time during which an ion undergoes said double deflection, wherein k is a whole number, and the maximum radial distance rmax of an ion subjected to a double deflection with respect to the center of said incident ion beam being: rmax (1/16) (Vmax)/(Va.d) L2/k wherein vmax is the maximum potential difference established between said two electrodes spaced at a distance d from each other, L is the length of said electrode in the direction of said incident ion beam and Va is the ion acceleration voltage in said direction.