Gamma Spectrometry Forum

Dear all,
I would like to share some details about my implementation of NuclearPhoenix' Open Gamma Detector board as a portable spectrometer and survey meter.
Details about the board can be found here:https://hackaday.io/project/185211-all- ... ectrometer
I am using a 1"x2" NaI(Tl) scintillator from OST Photonics, coupled to 2x2 SiPM array.
https://github.com/OpenGammaProject/Mic ... rray-Board
The SiPM are MicroFC-60035, which have gotten considerably less expensive recently, making a 2x2 array affordable: Everything is installed in a sturdy enclosure and the endcaps for the scintillator are 3D printed from flexible TPU filament: The top lid of the enclosure houses a LiPo battery, a charger circuit, an On/Off switch, a display toggle button and a speaker On/Off switch for future use. I am currently using a small SSD1306 display, modifying the code to accept the bigger SH1106 display is on my todo list (still struggling with that).

Part 2
The display button toggles between energy spectrum mode and geiger (cps only) mode: The one minute spectrum of a Radium dial already shows the characteristic peaks.

There is a USB C connector for charging and to hook the unit up to a computer for more serious spectrometry. The unit is designed to interface directly with this web app
https://spectrum.nuclearphoenix.xyz/

All involved software is in very active development
https://github.com/OpenGammaProject
with new features and performance improvements coming frequently.

Regarding performance, I was able to detect a spicy Radium dial from an old aircraft instrument from a few meters away and on the other extreme, I could not get the electronics or software to crash at more than 17000 cps:

Robert,

Thanks for posting, nice multi disciplinary project.

Steven 😊

Robert,

completely forgot to reply to your post. I still think it's a really well-made device, especially with the 3D-printed handle and the LiPo addon.
Good job!

Thanks guys!

The 3D-printed handle is from thingiverse, so I cannot take credit for that ;)
https://www.thingiverse.com/thing:2561532
Regarding the LiPo addon, it helped a lot that VSys and VBus are accessible on breakout pins on the detector board.

Robert

Very nice!

How did you manage to mount the display? It looks like it is somewhat wedged between the top cover of the case and your 3D-printed display mount, is there something else in there that we cannot see?

Matthias,
I used this design as a basis
https://www.thingiverse.com/thing:5278349
and scaled it to fit a SSD1306 display. It is attached to the case with double sided 3M tape.
There is only a small elongated hole in the top of the enclosure for the four wires so I can upgrade to the SH1106 display later.

Update:
The bigger SH1106 display is working now (thanks Matthias!) and showing a spectrum of my Cs-137 checksource.
The ticker is operational, too.

I just finished a downsized version, utilizing a 1" dia x 1" NaI(Tl) scintillator and a 2x2 SiPM matrix.