Electron Microscopy

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To conduct an experiment where the aim is to confirm if an controlled object follows the theoretical predictions, it is very important that the experiment do what you think it does, otherwise you cannot draw any conclusions.

There are a number of ways to design the microparticle ejector, and several parameters that will influence the results. Of course it is possible to do numerical simulations to predict the result, but because of the complexity, experimental methods will have to be used to confirm if the ejector works the way we want it to.

But how do you observe particles with individual sizes way below what you can view with your eye, and even a light-optical microscope?

The answer to this is electrons and the de Broglie wavelength, a formula derived in early 20th century by Louis de Broglie, telling us that all matter have a wavelength inversely proportional to momentum.

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This awesome formula tells us that all matter not only acts like particles, it also exhibits properties of waves!

From the equation, we see that for an electron the wavelength can be made sufficiently small by increasing its momentum by e.g. accelerating it through a potential. This result, combined with a lot of other beautiful techniques such as electromagnetic lens systems and vacuum pumps, made it possible to manipulate “electron waves” in almost the same way as light waves in optical microscopes, creating the first electron microscopes in the 1930’s.

Scanning Electron Microscope model JEOL JSM-7500F

A Scanning Electron Microscope (SEM) is a common type of electron microscope, which will be used to analyze the particles from the ejector. Before being allowed to use the SEM, one has to go through some training sessions since there are so much things going on when using the SEM. After that, we will be able to confirm if the particles are separate or not, by actually looking at them. Technology ♥

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