Secondary ion mass spectrometer

Claim 1

A secondary ion mass spectrometer system adaptable for placement in close proximity to a specimen surface, comprising (a) an ion collection lens having three spaced-apart conical sections aligned along a first axis, including a first conical section having means for electrostatically focusing ions into a stream along said first axis, a second conical section having means for electrostatically attracting and accelerating said ions emitted from said specimen surface, and a third conical section having means for electrostatically influencing said ions for energy window matching to an entrance aperture of a quadrupole mass spectrometer; (b) an electrostatic ion deflector positioned adjacent said ion collection lens, said deflector having four mutually orthogonal plates equally spaced about said first axis; (c) an ion energy spectrometer having an entrance aperture aligned with said first axis, said ion energy spectrometer further comprising two 90. sectors of spherical arcuate plates having an inlet aligned with said entrance aperture and having an exit aligned with an exit aperture, said exit aperture being aligned with a second axis; (d) an ion bunching and deceleration lens assembly positioned adjacent said exit aperture and aligned along said second axis; (e) said quadrupole mass spectrometer having its entrance aperture and having an exit aperture respectively aligned along said second axis; and (f) an ion detector having an entrance aperture aligned along said second axis immediately adjacent the exit aperture of said quadrupole mass spectrometer, said ion detector having means for generating electrical signals responsive to and representative of ions received through said entrance aperture.