The Quanta 200 FEG Environmental Scanning Electron Microscope (ESEM) uses a field-emission gun (FEG) electron source in an exceptionally high chamber pressure environment.
It combines two main advantages:
- Nanometer resolution and a high signal to noise ratio in both regular high vacuum and environmental (wet) modes.
- Real “wet” mode (100% humidity in the specimen chamber) and a possibility to examine specimens with a high vapor pressure in the chamber. It is provided by a differential pumping vacuum system and a series of pressure-limiting apertures in addition to a patented gaseous secondary electron detector.
By utilizing a cooling Peltier stage and a high water vapor pressure in the specimen chamber it is possible to achieve high levels of humidity. In these conditions wet or hydrated specimens (cells, plant samples, tissue, etc.) will not dry and introduce any artifacts while being examined in the SEM. Dynamic experiments such as drying or crystallization processes can be examined as well.
Low vacuum mode is very useful for observing non-conductive specimens such as paper, plastics, ceramics, fibers, fabrics, and outgassing materials.
The Quanta 200 FEG can be switched between three vacuum modes enabling the investigation of conductive, non-conductive and high-vacuum incompatible materials:
High vacuum (typically 10-5 mbar) for imaging and microanalysis of conductive and/or conventionally prepared specimens;
Low vacuum (<1.3 mbar) for imaging and microanalysis of non-conductive specimens without preparation;
ESEM mode (<26 mbar) for high-vacuum incompatible specimens, which were previously impossible to investigate with conventional SEM methods.
To schedule servicies on ESEM: