Scanning Electron Microscopy (SEM) Concepts
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- Опубліковано 13 жов 2019
- Download the SEM Concepts Handout: bit.ly/31bAyv8
This is a discussion of five of the main physical concepts involved in scanning electron microscopy (SEM) - voltage, current, working distance, and the various electron interactions (e.g. the generation of secondary electrons, backscattered electrons, and characteristic x-rays). This video includes a brief introduction on how to simulate beam-specimen interactions using free CASINO Monte Carlo software (www.gel.usherbrooke.ca/casino....
A note about the coating layer: a coating layer will help to avoid charging when working with non-conductive or semi-conductive samples. Please carefully consider if going to higher voltages is appropriate for your sample.
There are additional critical concepts to consider when operating an SEM that are not covered in this video, including: dwell time, pixel resolution, how to achieve a good signal-to-noise ratio image/measurement, and how some of these parameters can effect image resolution. These concepts are explained in detail in the book by Goldstein et al 'Scanning Electron Microscopy and X-Ray Microanalysis'.
A complimentary video will be made to discuss additional important concepts and considerations when changing the working distance (i.e. uneven samples, signal collection efficiency), to highlight the limitations when working with different sample types.
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Download the SEM Concepts Handout: bit.ly/31bAyv8
Download the Considerations for Optimal SEM Imaging Results Handout: bit.ly/2q8gTiQ
Download the SEM Alignment Handout: bit.ly/2OgnvDL
Download any of the KNI's Microscopy Handouts: bit.ly/2M7I9GK
For more information, view the KNI's Microscopy Lectures: bit.ly/2IH6Es8
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Presented by Matthew Sullivan Hunt, PhD
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Disclaimer: This video is intended to serve as supplemental information and cannot replace in-person instrument training. Caltech and KNI are not responsible for how the presented information is translated for use in other facilities.
For information or questions about this video, contact kni@caltech.edu
Excellent video. Simulation part may seem not very useful to some listeners but monte carlo simulation is a very valuable addition to the lecture. Good job!
Excellent, I have never seen that so clearly state everything on one page before. Good job!!!
Excellent.
Great video! Thank you!
Exceptional... Thank you very much for this.
Thank you!
Thank you 👍🏻
great PPT
EXCELLENT!!!!!!!!!
Thanks a lot.
thank you
Other videos are not available..!
Please would you make it available
Hello! The video on Eucentric Height is currently set to private. Can you please make it available to the public? I appreciate the videos content. Thank you!
How does the detectors recognize that wich electrons are primari and secondary electrons?
All links to handouts/presentations are now dead. Can you make these files available again?
Excellent presentation!
What kinda differences would be there if I go for SEM testing of (1) cement paste i.e., cement plus water (2) mortar i.e., cement + water + sand, and (3) concrete i.e., cement + water + sand + gravels? Also let me know which case would be more appropriate in order to discuss the phase characterization of the products formed therein such as the main hydration products e., CSH (calcium silicate hydrate) and CH (calcium hydroxide).
One more thing.....how can I assess the structures of either of these two hydration products in which case, I have to first dehydrate my samples prior to going for SEM testing (during the sample preparation stage)? So if dehydrated, there would be neither CSH nor CH in the prepared samples for SEM.
What graphics program did you use to make the handout?
These handouts were made in Adobe Illustrator