On the dead time problem of a GM counter

Area of Science:

• Nuclear Instrumentation
• Radiation Detection Physics

Background:

• Accurate dead time modeling is crucial for precise radiation measurements using Geiger-Müller (GM) counters.
• Existing models often struggle to accurately represent GM counter behavior across all counting rates.

Purpose of the Study:

• To evaluate the performance of different dead time models for GM counters.
• To identify the most suitable model for describing GM counter characteristics.
• To propose a practical model for high counting rate scenarios.

Main Methods:

• Utilized an activated (56)Mn decaying source for dead time characteristic studies.
• Employed a Geiger-Müller (GM) probe and multichannel scaler to record counting rates over 20 half-lives.
• Compared experimental data against generalized, non-extending-extending (NE-E), and extending-nonextending (E-NE) dead time models.

Main Results:

• The non-extending-extending (NE-E) series model demonstrated superior agreement with measured GM counter data compared to other models.
• The NE-E model provided results within 10% accuracy up to approximately 10 kcps true counting rate.
• Limitations of the NE-E model at higher counting rates were observed and discussed.

Conclusions:

• The NE-E series model is effective for GM counter dead time characterization at moderate counting rates.
• A phenomenological model is proposed as a practical solution for describing GM counter behavior at counting rates exceeding approximately 10 kcps.
• Further investigation into the limitations of current models at high counting rates is warranted.