Patent Number: 063103532
Section: claims

1. A mass spectrometer comprising: a source region;  a shielded lens including at least two conducting electrodes;  an analysis region; and  a detector region;  wherein said shielded lens produces and adjusts the position of a focal point of ions produced in said source region.  an ion source region;  a shielded lens;  a flight region; and  a detector region;  wherein said source region, said shielded lens, said flight region and said detector region are positioned such that ions produced in said source region traverse through said shielded lens and said flight region to said detector region; and  wherein said shielded lens produces and adjusts the position of focal point of said ions. 2. A mass spectrometer according to claim 1, wherein said shielded lens further comprises a conducting cylindrical electrode. 3. A mass spectrometer according to claim 2, wherein said cylindrical electrode has an axis which is coaxial with a path of said ions. 4. A mass spectrometer according to claim 2, wherein said conducting electrodes are conducting planar grids. 5. A mass spectrometer according to claim 4, wherein said cylindrical electrode is positioned between said conducting planar grids. 6. A mass spectrometer according to claim 4, wherein said planar grids are positioned perpendicular to said path of said ion beam. 7. A mass spectrometer according to claim 4, wherein said cylindrical electrode is electrically biased with respect to said planar grids to focus or defocus ions. 8. A mass spectrometer according to claim 4, wherein said planar grids have more than 8 wires per centimeter (20 wires per inch). 9. A mass spectrometer according to claim 4, wherein said grids have 8 wires per centimeter (twenty wires per inch). 10. A mass spectrometer according to claim 1, wherein said shielded lens comprised of at least two conducting cylindrical electrodes and at least one conducting planar grid. 11. A mass spectrometer according to claim 10, wherein said conducting cylindrical electrodes have an axis which corresponds to the nominal path of said ions. 12. A mass spectrometer according to claim 11, wherein a plane occupied by said planar grid is perpendicular to said axis. 13. A mass spectrometer according to claim 11, wherein said planar grid is positioned in a path of said ions. 14. A mass spectrometer according to claim 11, wherein said planar grid is positioned at an end of said conducting cylindrical electrodes. 15. A mass spectrometer according to claim 1, wherein said shielded lens comprises at least two planar conducting electrodes and at least two conducting planar grids. 16. A mass spectrometer according to claim 15, wherein said planar conducting electrodes are positioned parallel to each other. 17. A mass spectrometer according to claim 15, wherein said planar conducting electrodes are positioned such that said ions pass there between. 18. A mass spectrometer according to claim 15, wherein said planar grids are perpendicular to the path of said ions. 19. A mass spectrometer according to claim 15, wherein at least one of said planar grids is positioned at each end of said planar conducting electrodes. 20. A mass spectrometer according to claim 1, wherein said shielded lens comprises at least two pair of parallel planar conducting electrodes and at least one conducting planar grid. 21. A mass spectrometer according to claim 20, wherein each of said pair is positioned on opposite sides of the nominal path of said ions. 22. A mass spectrometer according to claim 20, wherein said planar grid is perpendicular to the nominal path of said ions. 23. An improved mass spectrometer according to claim 20, wherein said planar grid is positioned at one end of said two pair of planar conducting electrodes. 24. A mass spectrometer according to claim 1, wherein said analysis region comprises a quadrupole mass analyzer. 25. A mass spectrometer according to claim 1, wherein said analysis region comprises a time-of-flight mass analyzer. 26. A mass spectrometer according to claim 1, wherein said analysis region comprises an orthogonal time-of-flight mass analyzer. 27. A mass spectrometer according to claim 1, wherein said analysis region comprises a coaxial reflectron time-of-flight mass analyzer. 28. A mass spectrometer according to claim 1, wherein said analysis region comprises a tandem time-of-flight mass analyzer. 29. A mass spectrometer according to claim 1, wherein said analysis region comprises an ion trap mass analyzer. 30. A time-of-flight mass spectrometer comprising: 31. A time-of-flight mass spectrometer according to claim 30, wherein said flight region is a field free drift region. 32. A time-of-flight mass spectrometer according to claim 30, wherein said shielded lens further comprises a conducting cylindrical electrode. 33. A time-of-flight mass spectrometer according to claim 32, wherein said cylindrical electrode has an axis which is coaxial with a path of said ions. 34. A time-of-flight mass spectrometer according to claim 32, wherein said shielded lens further comprises conducting planar grids. 35. A time-of-flight mass spectrometer according to claim 34, wherein said cylindrical electrode is positioned between said conducting planar grids. 36. A time-of-flight mass spectrometer according to claim 35, wherein said planar grids are positioned perpendicular to said path of said ions. 37. A time-of-flight mass spectrometer according to claim 35, wherein said cylindrical electrode is electrically biased with respect to said planar grids to focus or defocus ions. 38. A time-of-flight mass spectrometer according to claim 35, wherein said planar grids have more than 8 wires per centimeter (20 wires per inch). 39. A time-of-flight mass spectrometer according to claim 35, wherein said planar grids have 8 wires per centimeter (twenty 24 wires per inch). 40. A time-of-flight mass spectrometer according to claim 32, wherein said shielded lens comprises at least two conducting cylindrical electrodes and at least one conducting planar grid. 41. A time-of-flight mass spectrometer according to claim 40, wherein said conducting cylindrical electrodes have an axis which corresponds to the nominal path of said ions. 42. A time-of-flight mass spectrometer according to claim 40, wherein a plane occupied by said planar grid is perpendicular to said axis. 43. A time-of-flight mass spectrometer according to claim 40, wherein said planar grid is positioned in a path of said ions. 44. A time-of-flight mass spectrometer according to claim 40, wherein said planar grid is positioned at an end of said conducting cylindrical electrodes. 45. A time-of-flight mass spectrometer according to claim 30, wherein said shielded lens comprises at least two planar conducting electrodes and at least two conducting planar grids. 46. A time-of-flight mass spectrometer according to claim 45, wherein said planar conducting electrodes are positioned parallel to each other. 47. A time-of-flight mass spectrometer according to claim 45, wherein said planar conducting electrodes are positioned such that said ions pass there between. 48. A time-of-flight mass spectrometer according to claim 45, wherein said planar grids are perpendicular to a path of said ions. 49. A time-of-flight mass spectrometer according to claim 45, wherein at least one of said planar grids is positioned at each end of said planar conducting electrodes. 50. A time-of-flight mass spectrometer according to claim 30, wherein said shielded lens comprises at least two pair of parallel planar conducting electrodes and at least one conducting planar grid. 51. A time-of-flight mass spectrometer according to claim 50, wherein each of said pair is positioned on opposite sides of the nominal path of said ions. 52. A time-of-flight mass spectrometer according to claim 50, wherein said planar grid is perpendicular to the nominal path of said ions. 53. A time-of-flight mass spectrometer according to claim 50, wherein said planar grid is positioned at one end of said two pair of planar conducting electrodes.