Stray Aperture in EMs
- Practical Electron Microscopy and Database -
- An Online Book -

http://www.globalsino.com/EM/  



 

This book (Practical Electron Microscopy and Database) is a reference for TEM and SEM students, operators, engineers, technicians, managers, and researchers.

 

=================================================================================

Stray radiation in EMs mainly originates from uncollimated electrons and characteristic and continuum x-rays. This stray radiation can hit the EM specimen especially when the specimen is thick, for instance, for TEM most effect is from the thicker regions in the outer parts of the specimens. Spurious x-rays of the samples can be generated from stray radiation. Fortunately, in modern EM systems, the stray aperture is used to protect the specimen from the impingement of x-rays because it can strongly absorb the signals from stray radiation and thus, improves the accuracy of the measurements.

Stray aperture for accurate EDS measurements in TEM system

Figure 3920. Stray aperture for accurate EDS measurements in TEM system.

Similar to stray apertures for EDS measurements, a collimator in an EDS detector in electron microscopes (EMs) is positioned at the front of the detector and constrains the X-rays entering it into parallel paths. The function of the collimator is to reduce the stray x-rays and backscattered electrons that do not originate from the specimen from entering the detector.

 

 

 

=================================================================================

The book author (Yougui Liao) welcomes your comments, suggestions, and corrections, please click here for submission. If you let book author know once you have cited this book, the brief information of your publication will appear on the “Times Cited” page.