Control of radiation damage in the TEM.
The problem of electron-beam damage in the transmission electron microscope is reviewed, with an emphasis on radiolysis processes in soft materials and organic specimens. Factors that determine the dose-limited resolution are identified for three different operational modes: bright-field scattering-contrast, phase-contrast and dark-field microscopy. Methods of reducing radiation damage are discussed, including low-dose techniques, cooling or encapsulating the specimen, and the choice of imaging mode, incident-beam diameter and incident-electron energy. Further experiments are suggested as a means of obtaining a better understanding and control of electron-beam damage.
Physics Department, University of Alberta, Edmonton, Canada T6G 2G7. regerton@ualberta.ca
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Egerton
D000818:Animals; D016477:Artifacts; D060733:Electromagnetic Radiation; D006801:Humans; D046529:Microscopy, Electron, Transmission / Q000379:methods*