FEG 1000 Field Emission Source Electron Gun

The FEG1000  features a field emission source for maximum current density and produces a 100 nm spot size at 5 nA. Optimised for Auger analysis at very high spatial resolution with SEM and SAM imaging, the gun is available with a PC-based data system.

Source
The electron source is a Schotty field emitter (ZrO/W). This type of source delivers a bright, highly-stable electron beam into the optical column. To ensure the stable operation of the field emission source, the gun must be differentially pumped. An ion pump is supplied as part of the FEG1000 package.

Optical Column
The FEG1000 has a two-lens column, a condenser lens and a final focus lens. These allow the user to select the current/spot size combination required for the analysis.
Beam Forming
The electron beam is focused onto the sample using a single electrostatic lens. The beam quality is optimised using the octopole stigmator.

Scanning
A quadrupole arrangement of electrodes is used to scan the electron beam. This compact arrangement minimises the distance from the focusing lens to the sample so that the smallest spot size can be achieved.

Magnetic Shielding
Mu-metal shielding is fitted in sensitive areas to prevent stray magnetic fields from affecting the beam quality or direction.