Thermo Scientific Apreo User's Operation Manual page 9

Column schematic overview
FIGURE 1-1:
CONDENSER
LENS(ES)
DEFLECTION
SYSTEM
FINAL LENS
SPECIMEN
Computer control
The xT microscope Server and Microscope Control (User Interface) software integrate SEM functionality within a
Windows 7 operating environment.
This software consists of programs defining specific instrument settings for particular applications, ensuring
reproducibility of complex procedures (for instance imaging, management of image capture, storage, and data
output devices etc.). They also control instrument hardware (the column, detector(s), stage, EDX, vacuum
functions etc.).
Vacuum system
The entire particle path from a source to a specimen must be under vacuum so that the particles do not collide with
air molecules.
Various levels of vacuum are necessary, so a Turbo Molecular Pump (TMP) backed by a scroll pre-vacuum pump
(PVP) obtains the necessary specimen chamber pressure.
High Vacuum (HiVac) mode
This is the conventional operating mode associated with all scanning electron microscopes.
Low Vacuum (LoVac) mode
In the gaseous mode the electron column is under lower pressure than the specimen chamber. This mode can use
water vapors from a built-in water reservoir, or an auxiliary gas that is supplied by a user and connected to the gas
inlet provided for this purpose. Observation of outgassing or highly charging materials can be made using this
mode without the need to metal coat the sample, which would be necessary for the conventional HiVac mode.
Stage
The Apreo has a computer-controlled high-accuracy five-axis stage for small samples. It offers precision specimen
computer controlled manipulation and automation of all axes for overall spatial orientation on highly repetitive or
extremely irregular samples.
Specimen exchanges take place through a chamber door that exposes the specimen stage when opened or through
the Quick Loader (option). An exchange time takes a few minutes; with the Quick Loader, an exchange is much
faster. Software and interlocks protect the system against damage and users against an injury.
C O N F I D E N T I A L – limited rights
Revision A Feb 2018
System overview: System capabilities
Electron
Source
LENS SYSTEM
SCAN UNIT
SCAN GENERATOR
DETECTION UNIT
M
User Manual 1-3