Radiation Counter Switching With Off-Time to Prevent Double Counting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional radiation detectors experience double-counting errors during continuous exposure due to the switching of counters, leading to inaccuracies in photon counting, particularly in short exposure times.
Innovation Solution
A radiation detector with a sensor, counters, and a control circuit that implements an off-time setting to prevent double counting by synchronizing counter switching with a trigger signal and using a time constant to manage counter operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If counter switching is performed in zero dead mode to eliminate dead time, then productivity is improved, but measurement precision deteriorates due to double-counting errors
Solution Approach 1:
The patent applies preliminary action by setting an off-time period before counter switching occurs. This off-time is calculated based on the pulse width characteristics of the radiation detector, ensuring that any lingering pulse from the previous counter period has completely decayed before the next counter begins counting. This preventive measure eliminates double-counting errors while maintaining continuous exposure capability.
Solution Approach 2:
The patent changes the temporal parameter of counter operation by introducing an off-time interval between counting periods. This parameter adjustment is optimized based on the pulse width characteristics of the specific radiation detector being used, allowing the system to maintain high productivity while achieving accurate photon counting by preventing pulse overlap across counter boundaries.
2Productivity
If counter switching frequency is increased to reduce dead time, then productivity is improved, but measurement precision deteriorates due to increased double-counting probability
Solution Approach 1:
The patent applies preliminary action by calculating and setting an appropriate off-time period before each counter switching event. This off-time is determined based on the pulse width characteristics of the radiation detector, ensuring that pulse decay is complete before the next counter begins operation. This preventive timing mechanism allows for high counter switching frequency while maintaining measurement accuracy.
Solution Approach 2:
The patent implements periodic action through the regular alternation of counter on/off states with a fixed off-time interval. This periodic switching pattern, synchronized with the pulse decay characteristics of the detector, enables continuous exposure operation while systematically preventing double-counting errors through rhythmic timing control.
3Measurement precision
If off-time is extended to prevent double counting, then measurement precision is improved, but productivity deteriorates due to increased dead time
Solution Approach 1:
The patent optimizes the off-time parameter by setting it equal to the pulse width of the radiation detector. This precise parameter matching ensures that the off-time is just long enough to prevent double-counting of decaying pulses, while being short enough to minimize the impact on overall counting efficiency. This optimized parameter setting achieves the balance between measurement precision and productivity.
Solution Approach 2:
The patent applies the discarding and recovering principle by intentionally discarding the brief off-time period when counters are not actively counting, in exchange for recovering accurate measurement data by eliminating double-counting errors. This trade-off is justified because the off-time prevents erroneous measurements, and the cumulative effect of accurate counting outweighs the temporary loss of counting capability during the off-time intervals.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively suppresses double counting and counting loss, enabling highly accurate radiation data acquisition even in short exposure times, aligning detected photon counts with theoretical curves and reducing errors.
Implementation Method 1
a sensor for generating a pulse when a particle of radiation is detected
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A radiation detector, a radiation measuring apparatus, and a method of setting a radiation detector, which can suppress a double count which occurs by detecting a single pulse duplicately with a plurality of counters in counter switching, and can acquire highly accurate data, are provided. A radiation detector (100) detecting radiation in continuous exposure, comprises a sensor (110) for generating a pulse when a particle of radiation is detected, a plurality of counters (140a) and (140b) provided for counting the pulses, a setting holding circuit (150) for holding a setting of an off-time for turning off any of the plurality of counters (140a) and (140b), and a control circuit (160) for switching the counter performing counting the pulses after a lapse of the off-time with respect to a trigger signal.