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US 2003/0226975 A1Published application
Wien filter and electron microscope using same
AssigneeJEOL Ltd.
InventorsG. Martinez Lopez, Katsushige Tsuno
Life of this patent
Estimating the term…
Abstract
A Wien filter is provided in which a less amount of secondary aberration is produced than conventional. This filter has 12 poles. These poles have front ends facing the optical axis. These front ends have a 12-fold rotational symmetry about the optical axis within the XY-plane perpendicular to the optical axis.
Claims13
A Wien filter having an optical axis substantially parallel to a Z-axis, the Wien filter producing at least a dipole electric field in the direction of an X-axis and a dipole magnetic field in the direction of a Y-axis, said Wien filter comprising:
- 12 poles extending substantially parallel to the optical axis in the direction of the Z-axis, said 12 poles having front ends facing the optical axis within an XY-plane, said front ends having a 12-fold rotational symmetry about the optical axis.
An electron microscope comprising:
- an electron gun for producing an electron beam;
- a Wien filter for passing only electrons having a certain energy, said electron beam being made to strike a sample via said Wien filter, said Wien filter having an optical axis substantially parallel to a Z-axis, said Wien filter producing at least a dipole electric field in the direction of an X-axis and a dipole magnetic field in the direction of a Y-axis;
- and
- 12 poles extending substantially parallel to the optical axis in the direction of the Z-axis, said 12 poles having front ends facing the optical axis, said front ends having a 12-fold rotational symmetry about the optical axis within an XY-plane.
1 more element
Dependencies are inferred from the claim text.