3 Product and Functional Description | 3.2 Main Components
ZEISS
3.2.4.4 SE Detector
Purpose
The SE detector is an Everhart-Thornley type detector. It detects SEs as well as BSEs.
Position
The SE detector is attached to the options ports plate.
1
2
4
5
3
6
Fig. 13: Schematics of the
detector
1
Preamplifier
2
Photomultiplier
3
Light guide
4
Scintillator
5
Collector grid
6
Specimen
Operating
Principle
Electrons moving to the detector are attracted/repelled by the collector grid and directed to the
scintillator. The electrons gain energy from the scintillator and thus are able to interact with a
phosphor layer, which generates photons (light). The light travels up a light pipe to a photomulti-
plier. The photomultiplier multiplies the flashes of light and outputs a signal that can be used for
imaging.
The collector voltage can be varied in the range between −250 V and +400 V.
A positive collector voltage generates an electrical field in front of the detector, thus directing the
low energy SEs towards the scintillator.
Info
For all standard applications, the collector bias should be set to +300 V.
3.2.4.5 Chamber CCD Camera
Purpose
The microscope contains a CCD camera (charge-coupled device camera) inside the specimen
chamber. It is referred to as the chamber CCD camera or chamberscope. It allows you to monitor
the position of the specimen stage and particularly the distance between the objective lens and
the specimen holder.
The chamber CCD camera is located at the backside of the specimen chamber. A second CCD
camera can be installed on the left-hand side of the specimen chamber.
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Instruction Manual ZEISS Crossbeam 550L, Crossbeam 550 | en-US | Rev. 3 | 349500-8122-000
Summary of Contents for Crossbeam 550
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