When the ambient field changes, the electron beam of the scanning electron microscope (SEM) / transmission electron microscopes (TEM) is deflected, causing loss of resolution and image distortion. The SC24 system stabilises the field by dynamically creating nearly equal and opposite field changes !!
The SC24 system comprises a magnetic field control unit, one or two magnetic field sensors and three orthogonal axis multicore cables, that are installed in the room where the field is to be cancelled. The SC24 can drive single loop and double loop room size cables. It also works with Helmholtz cables that are attached to a frame around the column. Three power amplifiers in the control unit drive currents through the cables to create a field of the opposite sign to the change in ambient field. The magnetic field sensor measures the resulting field and real time negative feedback reduces the ambient field by the loop gain of the system. The system is dynamic, automatically responding to field changes within 100 µs.
- Makes the ambient magnetic field “OK” for the electron microscope
- Best fit for all scanning electron microscopes (SEM) / transmission electron microscopes (TEM)
- Adapts to field changes within 100 µs
- Touch screen intelligent user interface with automatic setup and DC reset
- Simultaneous AC & DC field display with choice of Tesla or Gauss unit
- Mixes dual sensors to create virtual sensor “inside” the EM column
- Use AC sensors for cancelling 50/ 60 Hz AC line fields or:
- Use DC sensors for cancelling tram and train DC fields and 50/60Hz
- Built-in test field generator
- Ethernet and USB ports for remote operation and monitoring