EDS in the STEM

An EPMA is able to provide a quantitative analysis with an accuracy of 1-2%, but the AEM is usually relatively poorer, with an accuracy which depends very much on the particular element and its concentration. However, the actual mass analysed by AEM can be as small as 10-22g. 

Ideally the EDS should only receive the X-rays from beam-specimen interaction volume, but it is not possible to prevent radiation from the microscope stage and 

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