I built a so-called "scintillation counter" with an Arduino UNO. It's a much more powerful and sensitive device than a conventional Geiger counter for detecting gamma radiation. It uses a scintillator crystal to convert the gamma-rays to visible light, a silicon photomultiplier (SiPM) to convert the light into current pulses and the Mini SiD board, a front-end signal processing board for SiPMs. The digital signal going from the Mini SiD is then fed into a digital pin on the Raspberry Pi Pico. The Pico essentially counts the pulses produced by the gamma radiation and outputs them to the Serial interface for later processing. There is also a sketch to use with an SSD1306 OLED.
As you can see, the count rate with this small 10 x 2.5 cm board is typically at around 25 counts per second (just natural background) with my setup here, whereas you typically display in counts per minute with Geiger counters.
Here is a close-up of the processing board (Mini SiD). This is the "main" thing I built in order to use it as easily as possible with micros such as the UNO (i.e. ATMega328P):
If you want to learn more about the project, this is all part of the Mini SiD project that I've been working on the past couple of months. Everything is fully open source and I have a Hackaday project page, as well as a GitHub repo with complementary documentation. It's fully certified as open hardware by the OSHWA
GitHub:
Hackaday:
There is already somebody who built himself a nice little device using a very similar approach to me here. The Mini SiD board he is using there is already outdated by now, but the form factor and principle of operation remain the exact same. Thanks to RD-Gammaspectra for the neat example!
Here is a great video on a DIY scintillation counter build:
This is the same user with the blog post and the image from above, but this time it's sort of a guide on how to build one yourself
You don't even need to use a Raspberry Pi Pico anymore. As I've shown on Hackaday and in my previous video, you can use a standard Arduino UNO or even less, something like an ATTiny...
By the way, if you want to get your hands on one of the Mini SiD boards or if you want to support this project, feel free to have a look at my Tindie store. I have fully-assembled boards in stock there, so it makes it much easier to get started without having to worry about (soldering) all the SMD parts. There is also an option to use Kitspace, of course, if you want to DIY everything on your own.
Beginning from tomorrow, 05/06/2023 there will also be a week-long discount of -33% of the price on Tindie, so it's very cheap currently.
I'm also trying to do more showcasing and some tutorial videos on Youtube at the moment, so stay tuned.
It's a mini SiD connected to a microcontroller that works like a voltage controlled oscillator with a buzzer! It'll change it's output tone frequency with the measured activity. There is a really cool video on GitHub (link above), that I can't really show you here, where he demonstrates the device packaged in a tube with a 3D printed handle. The samples he has collected here are pretty impressive, especially since he's got no problem detecting the rocks already from a couple of meters away.
I finally came around to finish the PCB layout for the latest (and probably last honestly) hardware revision of the Mini SiD. In short, this is a small-ish quality-of-life update with some nice changes that should make it easier to use, while still not changing a whole lot fundamentally.
