SEM digital image acquisition with ADC microcontroller

After almost one year from the start of this project, I’ve finally succeeded in recording my first digital images from my vintage analog SEM using a Teensy 3.2 microcontroller and a simple computer script. The whole project has been inspired by Ben Krasnow who shared his precious project, computer side code and Teensy sketch which…

High vacuum pumping system revamped with new turbomolecular pump

Uncle SEM was equipped with a diffusion pump (DP) which had the task to pump the chamber down to high vacuum around E-6 Torr.   Oil Diffusion Pumps Oil diffusion pumps have some nice pros, like being completely free from mechanical parts making them vibration free, easy maintenance (cleaning and oil refill every 2-3 years…

New rotating specimen stub holder for my SEM

Uncle SEM was equipped with two different specimen holders when he joined the crew: one could only hold one 10 mm specimen stub and the other one was designed to hold bigger samples inside a 26mm wide plate. Unfortunatly, the bigger holder is centered under the objective aperture, so that it was impossible to just…

SEM Chamber-scope: adding a camera inside SEM chamber.

Most of modern SEMs use a chamber-scope to watch what’s happening in the chamber. A camera is useful to check which stub is currently under the objective of the microscope. My old analogic SEM didn’t of course have any, but there are still two side empty holes in the chamber, which can be used for…

SEM condenser lens pole piece cleaning and objective aperture replacement.

My old uncle SEM didn’t have much maintenance in the past, so I had to start some ordinary cleaning of its parts. There were some astigmatism problems, which at some magnification I couldn’t fix with the stigmator. The stigmator is a circuit which controls 8 electromagnetic coils which bend the electron beam so that its…

Lathe/milling machine joins the family!

I have finally acquired a lathe/milling machine from Damato Macchine, model BVB25/3L. The lathe chuck can hold bars up to 250mm. I’m planning to use it for building parts for my projects and it’s going to be equipped with tools for working inox steel as well since that’s the only suitable metal for SEM applications….

First pictures taken from uncle SEM’s slow scan

I could finally get some satisfying images in my last SEM session. The slow scan duration is 60 seconds and my Canon 600D camera can only keep its shutter open for 30 seconds. So I had to switch to “bulb” setting and keep the button pressed for the duration of the whole scan. I could…