Input lens and electron spectrometer
AssigneeJEOL Ltd.
InventorTatsuya Uchida
Life of this patent
Estimating the term…
Abstract
An input lens is provided which has a large acceptance solid angle for electrons. The input lens is for use in an electron spectrometer and disposed between an electron source producing electrons and an electron analyzer in the electron spectrometer. The input lens has a reference electrode at a reference potential, a slit, first through nth electrodes, where n is an integer equal to or greater than three, arranged between the reference electrode and the slit, and a second mesh attached to the first electrode. The first through nth electrodes are arranged in this order along an optical axis. The second mesh is at a potential higher than the reference potential.
Claims8
An input lens for use in an electron spectrometer and disposed between an electron source producing electrons and an electron analyzer in the electron spectrometer, said input lens comprising:
- a reference electrode at a reference potential;
- a slit;
- first through nth electrodes, where n is an integer equal to or greater than three, arranged between the reference electrode and the slit;
- and
- a mesh attached to the first electrode;
- wherein said first through nth electrodes are arranged in this order along an optical axis;
- wherein said mesh is at a potential higher than said reference potential;
- wherein a distance between an mth electrode, where m=2, 3, . . . , n−1, and the optical axis is less than both a distance between an (m−1)th electrode and the optical axis O and a distance between an (m+1)th electrode and the optical axis O;
- and
- wherein an electric field is produced between said reference electrode and said mesh and induces a positive spherical aberration, and wherein the second through nth electrodes produce electric fields which together induce a negative spherical aberration.
Dependencies are inferred from the claim text.