The Environmental Scanning Electron Microscope (ESEM) differs from a conventional SEM in that a differential pumping system maintains a pressure of gas (typically H2O) in the specimen chamber whilst the gun remains at high vacuum . Ionizing collisions between electrons and these gas molecules create positive ions which drift down onto the sample providing a mechanism for neutralising specimen charge. It is therefore possible to image insulating samples without the need for a metallic coating. The presence of water vapour in the chamber also means that a high relative humidity can be maintained and therefore samples can be imaged in a hydrated state without the need for dehydration and fixation.
|Translated title of the contribution
|Imaging dynamic biological processes with ESEM – A proof of principle study on plant tissue
|Title of host publication
|M.A. Pabst, G. Zellnig
|133 - 134
|2, Life Sciences
|Published - 2009