Radioactivity

Minerals radioactivity measurement.

Construction of scintillator detectors for the measurement of rocks and minerals radioactivity with Arduino MEGA 2560.

In this section, I describe the equipment I have built to measure the radioactivity of minerals and rocks. The majority of the rocks have a low activity level except for uranium and thorium ores. I have first used a low cost commercial Geiger counter which is working very well for high activity samples but requires high counting times of about 12 hours to reach a good detection limit for regular rocks. I decided then to build my own detectors with scintillators crystals, silicon photomultipliers (SiPM) and Arduino microcontroller as a counting system. I have also used the Theremino multi channel analyzer software to record some gamma spectra of the very active samples. However, the main goal of this work was to make a counter sensitive enough to measure a wide range of materials. In addition, the cost of the design should be as low as possible. As I have tried several scintillator crystals, I had to build different electronics for the signal conditioning. After testing, I reached the conclusion that the best detector for this purpose was the classical NaI scintillator, thus, with this in mind it would be possible to further simplify the design and lower the cost.

	Hardware description of the scintillator detectors: NaI: sodium iodide activated with thallium CdWO4: cadmium tungstate LYSO: lutetium yttrium silicate Plastic with organic scintillator
	Description of the electronics necessary to detect and shape the pulses from the detectors for counting or energy distribution measurement.
	Arduino microcontroller for pulses counting with scintillators. FTLAB sensor (gamma detector with PIN diodes) connected to Arduino Mega 2560 microcontroller.
	Software for the radioactivity counters: 1. Scintillators counters software. 2. Gamma FTLAB module software.
	Tests of the scintillator detectors. Pulse shape for counting and energy distribution.
	Gamma spectroscopy with the Theremino MCA software measured on the most radioactive samples. https://www.theremino.com/en/downloads/radioactivity
	Minerals radioactivity measurements. 1. Scintillators 2. Geiger counter and FTLAB detector Comparison of the different counters for the best detection limits.