Portable spectrometer / survey meter

[RobertD]

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:

IMG_20230508_102418.jpg

Everything is installed in a sturdy enclosure and the endcaps for the scintillator are 3D printed from flexible TPU filament:

IMG_20230509_132249.jpg

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.

IMG_20230509_132423.jpg

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).

IMG_20230509_134119.jpg

[RobertD]

Part 2
The display button toggles between energy spectrum mode and geiger (cps only) mode:

IMG_20230509_133803~2.jpg

IMG_20230509_133058~2.jpg

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.

IMG_20230509_133344.jpg

The unit is designed to interface directly with this web app
https://spectrum.nuclearphoenix.xyz/

[RobertD]

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:

IMG_20230430_075332.jpg

[Sesselmann]

Robert,

Thanks for posting, nice multi disciplinary project.

Steven 😊

[NuclearPhoenix]

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!

[RobertD]

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

[NuclearPhoenix]

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?

[RobertD]

Matthias,
I used this design as a basis
https://www.thingiverse.com/thing:5278349
and scaled it to fit a SSD1306 display.

IMG_20230518_092900.jpg

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.

[RobertD]

Update:
The bigger SH1106 display is working now (thanks Matthias!)

IMG_20230517_193242.jpg

and showing a spectrum of my Cs-137 checksource.
The ticker is operational, too.

[RobertD]

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