Patent Number: 
Section: claims

1. A neutron generator apparatus, comprising:means defining an expansion cavity;an ion source disposed in said expansion cavity for producing ions in said expansion cavity;means defining an acceleration gap cavity;a metal extraction plate interposed between said expansion cavity and said acceleration gap cavity and having defined therein an aperture for channeling said ions from said expansion cavity into said acceleration gap cavity; anda metal target disposed in said acceleration gap cavity and separated from said extraction plate by an acceleration gap, said target and said extraction plate adapted to be biased relative to one another to accelerate said ions across said acceleration gap in an acceleration direction to strike said target, said target adapted to release neutrons in response to being struck by said accelerated ions;wherein said acceleration gap cavity has a rectilinear cross section in said acceleration direction. 2. The apparatus of claim 1, wherein said extraction plate includes a surface metallization deposited on a substrate, generally defining an ellipse, and facing said target. 3. The apparatus of claim 2, wherein said target includes a surface metallization deposited on a substrate, generally defining an ellipse, and facing said surface metallization of said extraction plate. 4. The apparatus of claim 1, wherein said accelerated ions form an ion beam having a generally rectilinear cross section in said acceleration direction. 5. The apparatus of claim 1, wherein said ion source includes a pair of surface metallization electrodes deposited on a substrate and separated by a spark gap. 6. The apparatus of claim 1, wherein said means defining said expansion cavity and said means defining said acceleration gap cavity include a substrate, and wherein said target and said extraction plate include respective metallizations deposited on said substrate. 7. The apparatus of claim 6, wherein said means defining said expansion cavity and said means defining said acceleration gap cavity include a plurality of substrate layers laminated together. 8. The apparatus of claim 6, wherein said substrate is one of a ceramic substrate, a semiconductor substrate and a printed circuit board substrate. 9. A neutron generator apparatus, comprising:means defining an expansion cavity;an ion source disposed in said expansion cavity for producing ions in said expansion cavity;means defining an acceleration gap cavity;a metal extraction plate interposed between said expansion cavity and said acceleration gap cavity and having defined therein an aperture for channeling said ions from said expansion cavity into said acceleration gap cavity; anda metal target disposed in said acceleration gap cavity and separated from said extraction plate by an acceleration gap, said target and said extraction plate adapted to be biased relative to one another to accelerate said ions across said acceleration gap in an acceleration direction to strike said target, said target adapted to release neutrons in response to being struck by said accelerated ions;wherein said extraction plate includes a surface metallization deposited on a substrate, generally defining an ellipse, and facing said target. 10. The apparatus of claim 9, wherein said target includes a surface metallization deposited on a substrate, generally defining an ellipse, and facing said surface metallization of said extraction plate. 11. The apparatus of claim 10, wherein said ion source includes a pair of surface metallization electrodes deposited on a substrate and separated by a spark gap. 12. A neutron generator apparatus, comprising:means defining an expansion cavity;an ion source disposed in said expansion cavity for producing ions in said expansion cavity, including a pair of surface metallization electrodes deposited on a substrate and separated by a spark gap;means defining an acceleration gap cavity;a metal extraction plate interposed between said expansion cavity and said acceleration gap cavity and having defined therein an aperture for channeling said ions from said expansion cavity into said acceleration gap cavity; anda metal target disposed in said acceleration gap cavity and separated from said extraction plate by an acceleration gap, said target and said extraction plate adapted to be biased relative to one another to accelerate said ions across said acceleration gap in an acceleration direction to strike said target, said target adapted to release neutrons in response to being struck by said accelerated ions. 13. A neutron generator apparatus, comprising:means defining an expansion cavity;an ion source disposed in said expansion cavity for producing ions in said expansion cavity, including a pair of electrodes separated by a spark gap, and a fuse that bridges across said spark gap and is burned away upon initial application of power to said electrodes;means defining an acceleration gap cavity;a metal extraction plate interposed between said expansion cavity and said acceleration gap cavity and having defined therein an aperture for channeling said ions from said expansion cavity into said acceleration gap cavity; anda metal target disposed in said acceleration gap cavity and separated from said extraction plate by an acceleration gap, said target and said extraction plate adapted to be biased relative to one another to accelerate said ions across said acceleration gap in an acceleration direction to strike said target, said target adapted to release neutrons in response to being struck by said accelerated ions. 14. The apparatus of claim 13, wherein said electrodes are provided as surface metallizations deposited on a substrate.