[posted] Nuclear Pioneer Multichannel Analyzer Gamma Spectrometer


I made with Teensy 3.5 my Multichannel Analyzer Gamma Spectrometer - Nuclear Pioneer.

What is Gamma Ray Spectrometer? When a radioactive decay happen, an element emit a beta particle, or an alpha particle or a gamma energy, or all together. Depending on the radionuclide type. Multichannel Analyzer is the device that can interpret the misterious signal coming from a scintiullation probe and to show gamma ray spectrum of the radionuclide under test. It helps to detect radioactive elements and to identify isotopes according to gamma energies they have in range of 32keV-3000keV.

What Nuclear Pioneer has in hardware? the electronics include High Voltage regulated power module for an external photomultiplier tube (600V-1000V), pulse preamplifier, Teensy 3.5, TFT LCD, encoder, regulated 400V high voltage for internal tiny Geiger Counter.

The MCA can work as robust gamma spectrometer and as scintillation counter survey meter. It has great count rate performance. It calculate energy compensated doserate in uSv/h units. It can subtract background spectrum in real time. It can detect gaussian peaks in real time. It has small libarary for most known isotopes like Am-241, Cs-137, Ra-226 and daughters, Co-60.

The photos of the MCA working with NaI(Tl) scintillation probe:
Radium-226 watch sample test:
IMG_3437 - Copy.jpg
the 63x63mm NaI(Tl) probe (aluminum tube) is on the left side connected with BNC cable. Test vintage radium watch from 1960...
Cs-137 sample:

Am-241 sample from smoke detector

Eu-152 sample:

Scintillation search mode:


Talking to iPhone BLE:

interior hardware view:
Last edited:
Several updates of the firmware released since my last post. I'll summarize only the current 4.12 here:

What is new in 4.12 firmware:

Library is structured into two groups. Now you can set in the RIID f(x) menu what type of the library to use: Industrial/N.O.R.M or Medical. Selected library hint is also shown on the main display as MED or IND. IND/N.O.R.M. includes:Cs-137, Am-241, Co-60, Co-57, Ba-133, Eu-152, Ra-226, Th-232, U-235, K-40 MED includes: I-131, Lu-177, F-18(beta) and following isotopes as it also used in Nuclear Medicine for calibration or procedures: Cs-137, Co-60, Co-57
I-131 assigned to the correct Medical classification.
Fixed false positive detection of I-131 caused by Ba-133 peaks
Fixed false positive detection of Bi-214 caused by Lu-177
Start logo of the device is replaced with a smaller image to free 137kBytes of storage memory for further updates.
Added F-18 511keV to the medical library, currently in beta mode.
Added blink notification for successful identification.

All previous bug fix and updates from 4.01-4.11 are included in 4.12
RIID Isotope Library Include: Cs-137, Ra-226, Th-232, Bi-214, Ba-133, Am-241, Lu-177, Eu-152, K-40, Co-60, U-235, I-131, Co-57,F-18


for previous firmware releases please visit the page: