Radiation Measurement Device Dose Correction
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Solution Overview
Problem
Radiation measurement devices, particularly scintillation detectors, suffer from spectrum-peak spread issues that lead to inaccurate measurements at lower energy ranges, and energy characteristics vary among different detectors, causing distortion in energy compensation.
Innovation Solution
A radiation measurement device configuration that includes a scintillation detector with a measurement unit equipped with a pulse amplifier, A/D converter, and calculation units to generate wave height spectra, correct dose rates by applying correction coefficients based on standard resolution values, and compensate for energy characteristic distortions using correction coefficients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a scintillation detector is used to measure radiation at environmental background levels, then detection sensitivity is improved, but spectrum-peak spread causes measurement accuracy to deteriorate at lower energy ranges
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing correction coefficients in a lookup table before actual measurement. The correction coefficients are computed based on the relationship between wave height spectrum channels and energy ranges, and this correction data is prepared in advance to compensate for spectrum-peak spread effects during measurement operations
Solution Approach 2:
The patent changes parameters by introducing correction coefficients that modify the raw measurement data. The correction coefficients are derived from the ratio of actual energy to indicated energy at each channel, and these coefficient values are applied to adjust the measured dose rates, thereby transforming the inaccurate measurements into accurate results
2Measurement precision
If wave height spectrum measurement is performed to compensate for energy characteristics, then energy characteristic compensation is improved, but device complexity increases due to additional correction calculations
Solution Approach 1:
The patent reduces complexity by performing the complex correction coefficient calculations in advance and storing them in a lookup table. During actual operation, the system only needs to retrieve pre-computed correction coefficients based on measured channel values, rather than performing complex real-time calculations, thereby simplifying the operational complexity while maintaining accuracy
Solution Approach 2:
The patent uses copying by creating a lookup table that stores pre-computed correction coefficients. Instead of recalculating complex correction factors during each measurement, the system copies and applies the appropriate pre-stored coefficient values, which significantly reduces computational complexity while preserving the accuracy of energy characteristic compensation
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 provides a high-accuracy radiation measurement device with improved energy characteristics by correcting dose rates and compensating for distortions, especially at lower energy ranges, resulting in more accurate and consistent measurements across different detectors.
Implementation Method 1
a NaI(T1) scintillation detector or a CsI(Tl) scintillation detector is utilized; the measurement range thereof is from 10 nGy/h to 10 μGy/b or 10 nSv/h to 10 μSv/h and the detection sensitivity thereof is high
Implementation Method 2
A bias voltage, a reverse voltage, is applied to a Si-PIN photodiode; an electron and a hole that are produced, for example, from a γ-ray that entered a depletion layer (I layer) are collected, respectively, by a cathode electrode (N-layer) to which a positive voltage is applied and by an anode electrode (P layer) to which a negative voltage is applied
Data Source
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AI summary
In a radiation measurement device in which respective wave height values of voltage pulses from a radiation detector are made to correspond to radiation energy values and a count that is the number of the voltage pulses is separately generated for each of a plurality of channels corresponding to the wave height values so that a wave height spectrum is generated and a dose of a radiation that has entered the radiation detector is calculated based on the wave height spectrum, based on a count in at least one channel, out of the plurality of channels, that includes a lower limit within a measurement range for the radiation energy value, a dose is corrected by calculating a portion thereof neglected as what is the same as or smaller than a measurement limit, so that a dose of a radiation that has entered the radiation detector is calculated.