Particle-optical component and system comprising a particle-optical component
US6642525B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 7, 2001 |
| Grant date | Nov 4, 2003 |
| Priority date | — |
| Expiry date | Sep 7, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/3175
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A magnetic lens assembly for providing a magnetic deflection field for a beam of charged particles is disclosed. The assembly includes a focusing lens device for providing a magnetic field which has substantially rotational symmetry in respect of a symmetry axis of the assembly and acts on the beam traversing the magnetic field as a focusing lens with an optical axis, and includes an axis shifting device for producing a corrective magnetic field which is superposable on the magnetic field provided by the focusing lens device and acts on the beam such that the optical axis is shiftable parallel to the symmetry axis of the assembly. The axis shifting device includes a first set of axially spaced apart rings which are positioned concentrically in respect of the symmetry axis and are made of a material which is substantially not electrically conductive and has a high magnetic permeability. At least one axis shifting coil is provided with a plurality of current conductor windings for producing the corrective magnetic field. The current conductor windings of the axis shifting coil engage around at least one of the rings of the first ring set.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.