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Towards higher resolution in electron beam sensitive specimens of biological origin
Author(s) -
Dobb M. G.,
Murray R.
Publication year - 1974
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.1974.tb03955.x
Subject(s) - resolution (logic) , electron diffraction , electron , cellulose , reflection (computer programming) , cathode ray , range (aeronautics) , beam (structure) , irradiation , materials science , optics , electron microscope , polymer , electron beam processing , zonal and meridional , high resolution , diffraction , chemistry , molecular physics , composite material , physics , nuclear physics , organic chemistry , geology , remote sensing , atmospheric sciences , artificial intelligence , computer science , programming language
SUMMARY The resolution of structurally significant detail in electron micrographs of organic polymers is limited by damage to the specimen during electron irradiation. The factors affecting the kinetics of the degradation of characteristic high angle reflections in the electron diffraction patterns of Cellulose I and II have been studied in an attempt to determine quantitatively the conditions under which meaningful high resolution micrographs may be recorded. In Cellulose I it was established that the decay of the 002 reflection during irradiation (in the range 0.6‐6.0 Am −2 ) is independent of dose‐rate. Moreover the meridional 040 and equatorial 002 reflections were found to decay at different rates. This latter finding indicates the importance of selecting the appropriate conditions for imaging a particular structural repeat in a specimen. Perhaps the most significant conclusion arising from this work is that specimen cooling in conjunction with low‐beam densities may be used to considerable advantage in obtaining meaningful higher resolution images than hitherto possible in beam‐sensitive materials.