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For electron microscopes without aberration corrections, the higherorder terms in Equation 3740 are overwhelmed by the positive, thirdorder spherical aberration and thus, we only need to consider the aberration coefficients up to thirdorder. However, for corrected microscopes the higherorder terms becomes dominant.

No Aberration Correction

Aberration Corrected 
Third order
aberrations corrected 
Fifthorder aberrationcorrected 
Illumination aperture size 
Small 
Larger 

Beam current 
Lower 
Sixfold increase for the same probe size (comparing with no aberration correction) [2] 
A factor of 100x increase for the same probe size (comparing with no aberration correction) [3] 
Time for chemical mapping 
Take
over an hour [1] 
Take shorter times 
EELS Measurement 
Better electron collection by EEL spectrometer 
Most of electron beam may fall outside the entrance aperture of the EEL spectrometer if the collection optics are improved 
[1] K. Kimoto, et al., Nature 450, 702 (2007).
[2] P. E. Batson, N. Dellby, O. L. Krivanek, Nature 418, 617 (2002).
[3] D. A. Muller, et al., Science, in press Feb 22 (2008).
