Study of dead time estimation method based on pulse interval distribution.

Area of Science:

• Nuclear instrumentation
• Radiation detection physics
• Signal processing

Background:

• Dead time in radiation detectors leads to undercounting, impacting quantitative analysis.
• Accurate dead time estimation is essential for correcting measured counts, particularly at high event rates.
• Existing methods may struggle with accuracy under high counting rate conditions.

Purpose of the Study:

• To develop and validate a method for estimating detector dead time at high counting rates.
• To improve the accuracy of radiation count restoration in quantitative analysis.
• To mitigate the effects of pulse pile-up in detector systems.

Main Methods:

• Implemented a pulse interval distribution measurement system using FPGA.
• Employed digital pole-zero cancellation to reduce pulse decay time constants.
• Utilized an EDXRF experimental platform for high counting rate verification.

Main Results:

• The system accurately estimates the true input counting rate, even at rates up to 600 kCPS.
• A relative error of less than 5% was achieved between theoretical and estimated true input counting rates.
• Dead time was successfully calculated based on measured and estimated true count rates.

Conclusions:

• The proposed method effectively estimates dead time in nuclear radiation detection at high counting rates.
• The digital pole-zero cancellation technique successfully reduces pile-up effects.
• The developed system offers a viable solution for accurate quantitative analysis in high-rate radiation detection scenarios.