Extended bradbury-nielson gate
AssigneeBruker Daltonics, Inc.
InventorMelvin Park
Life of this patent
Estimating the term…
Abstract
A method and apparatus for analyzing ions by determining times of flight include using a deflector to direct ions away from their otherwise intended or parallel course. Deflectors are used as gates, so that particular ions may be selected for deflection, while others are allowed to continue along their parallel or otherwise straight path, from the ion source, through a flight tube, and eventually, to a detector. According to the present invention, an extended Bradbury-Nielson gate, in the form of a series of plates, with equal but alternating opposite polarity potentials, is used as an ion deflector or gate.
Claims20
A time of flight mass spectrometer comprising:
- an ion source region for generating ions;
- a flight tube region;
- a mass selector for selecting which of said ions are deflected and which of said ions are detected;
- and
- a detector for detecting said ions that are not deflected;
- wherein said mass selector impedes the travel of said ions by deflecting said ions into one of two directions,
- wherein said mass selector comprises more than two conductive plates each having a cross-sectional area which extends in the time of flight direction aligned such that substantially all ions are deflected away from the direction of ion propagation along said flight tube region, and
- wherein at least one of said plates is energized.
A mass selector for use in a time-of-flight mass spectrometer comprising a flight tube, an ion source, and a detector, said ion source producing ions that travel through said flight tube, wherein said mass selector comprises a plurality of metal plates each having a cross-sectional area which extends in the time of flight direction, wherein at least one of said metal plates is energized, and wherein said mass selector impedes said travel of certain of said ions by deflecting said certain ions in a uniform manner.
A method for analyzing ions by measuring ion flight times, wherein said method comprises the steps of:
- generating ions at the surface of a sample plate, said sample plate being biased to a potential;
- creating a beam of said ions by accelerating said generated ions toward an extraction plate which is held at ground potential;
- focusing said beam of ions by applying an electric field to a lens arrangement positioned in the path of said ion beam between said extraction plate and
- a mass analyzer;
- and
- removing unwanted ions from said ion beam by deflecting substantially all of said ions away from the direction of said ion beam by a mass selector comprising a plurality of conductive plates each having a cross-sectional area which extends in the direction of said ion beam.
Dependencies are inferred from the claim text.