ZEISS
3 Product and Functional Description | 3.3 Optional Components and Accessories
Operating
Principle
The aSTEM detector is a pneumatically retractable multi-mode detector with a 12-stub specimen
holder for bright-field and dark-field detection.
The diodes of the aSTEM detector collect transmitted electrons below the ultrathin specimen.
A special arrangement of the diodes allows a parallel detection of bright field (BF), oriented dark
field (ODF), annular dark field (ADF), and high angle annular dark field (HAADF). There are one
bright field segment (S1), two dark field segments (S2 and S3), one annular dark field segment
(S4), and one high angle annular dark field segment (S5).
Two different models are available:
§
The aSTEM4 allows detection of four channels in parallel.
§
The aSTEM1 only collects one signal at a time.
S1
S2
S3
S4
S5
S3
S2
Fig. 25: The
detector head and the arrangement of its diodes
Operating Modes
The most commonly used STEM modes are predefined and can be selected from the drop-down
menu in the STEM Control panel.
The diagram in the STEM Control panel displays details concerning the diode status and the diode
arrangement.
Each diode segment can have the following status:
§
On: The signal is added to the total signal
§
Inverted (Inv.): The signal is inverted and then added to the total signal
§
Off: The signal is not used
NOTICE
Risk of property damage: Motorized specimen stage
Risk of damaging the detector when operating the motorized specimen stage.
4
Retract the detector head completely after you have finished the work with the detector.
Instruction Manual ZEISS Crossbeam 550L, Crossbeam 550 | en-US | Rev. 3 | 349500-8122-000
51
Содержание Crossbeam 550
Страница 135: ......