Axial CI source—off-axis electron beam
AssigneeThermo Finnigan LLC
InventorsScott T. Quarmby, Edward B. McCauley, George B. Guckenberger
Life of this patent
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Abstract
An ion source includes an electron generator, an ionization chamber, and a magnetic field. The electron generator is configured to produce electrons. The ionization chamber has an electron entrance aperture through a first wall, an ion exit aperture through a second wall, and an axis. The ionization chamber is configured to produce ions. The magnetic field is arranged to confine electrons in a beam directed through the electron entrance aperture, in a direction within 45 degrees of parallel to the axis, and towards a location displaced from the ion exit aperture.
Claims7
An ion source comprising:
- an electron generator configured to produce electrons;
- an ionization chamber having an electron entrance aperture through a first wall and an ion exit aperture through a second wall, the ionization chamber configured to produce ions;
- a magnetic field arranged to confine electrons in a beam directed through the electron entrance aperture;
- an electron dispersive mechanism configured to disperse the electrons within the ionization chamber,
- the electron dispersive mechanism including a magnetic shielding configured to reduce the magnetic fields within at least a portion of the ionization chamber.
A method comprising:
- generating electrons;
- directing electrons in a beam through an electron entrance aperture of an ionization chamber,
- wherein a magnetic field is arranged to confine electrons in the beam being directed through the electron entrance aperture;
- dispersing the electrons within the ionization chamber with an electron dispersive mechanism, the electron dispersive mechanism including a magnetic shielding configured to reduce the magnetic fields within at least a portion of the ionization chamber;
- producing ions within the ionization chamber;
- and
- directing the ions as a beam through the ion exit aperture.
Dependencies are inferred from the claim text.