Study of two different coincidence counting algorithms in TDCR measurements

Area of Science:

• Nuclear physics
• Metrology
• Radiochemistry

Background:

• Triple-to-Double Coincidence Ratio (TDCR) is a key technique in radioactivity measurements.
• Extending-type dead-time correction is crucial for accurate TDCR results.
• Two logics, Common Dead-Time (CDT) and Individual Dead-Time (IDT), are used for dead-time correction.

Purpose of the Study:

• To compare the performance of CDT and IDT counting logics in TDCR measurements.
• To evaluate the agreement between the two logics across various radionuclides and experimental conditions.
• To assess the impact of dead-time correction strategies on activity measurements.

Main Methods:

• Experimental measurements using three setups with pure beta-emitters (³H, ¹⁴C, ⁶³Ni, ⁹⁰Sr/⁹⁰Y) and ²²²Rn.
• Monte Carlo (MC) simulations of TDCR events using a dedicated code.
• Comparison of activity measurements obtained with CDT (MAC3 module) and IDT (nanoTDCR device) logics.

Main Results:

• Excellent agreement between CDT and IDT for ³H, ¹⁴C, ⁶³Ni, and ⁹⁰Sr/⁹⁰Y, with relative deviations < 0.27%.
• Slight deviations observed for ²²²Rn measurements, attributed to differences in double coincidence counting rates.
• MC simulations confirmed excellent agreement for ³H (< 0.24% deviation).
• IDT showed an advantage in MC simulations for ³H by reducing double coincidence dead-time while maintaining accuracy.

Conclusions:

• CDT and IDT logics provide highly consistent results for TDCR measurements of various radionuclides.
• The IDT logic offers potential advantages in reducing dead-time, particularly in simulated scenarios.
• Both methods are reliable for accurate radioactivity determination, with minor differences noted for specific isotopes like ²²²Rn.