Radiation detection device, radiation detection method, and computer program product

Patent metadata

Field	Value
Publication number	US-9864079-B2
Application number	US-201514963805-A
Country	US
Kind code	B2
Filing date	Dec 9, 2015
Priority date	Feb 5, 2015
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

According to an embodiment, a radiation detection device includes a scintillator layer, a plurality of detectors, a setting unit, an identifier, and a corrector. The scintillator layer is configured to convert radiation into scintillation light. The detectors are arranged along a first surface facing the scintillator layer to detect light. The setting unit is configured to set one of the detectors as a first detector to be corrected. The identifier is configured to identify, out of the detectors, a second detector that detects a synchronization signal synchronizing with a first signal detected by the first detector. The corrector is configured to correct an energy spectrum of light detected by the first detector on the basis of a second signal serving as the synchronization signal in signals detected by the second detector, the first signal, and characteristic X-ray energy of a scintillator raw material constituting the scintillator layer.

First claim

What is claimed is:

1. A radiation detection device, comprising:
a scintillator layer configured to convert X-rays into scintillation light;
a plurality of detectors arranged along a first surface facing the scintillator layer to detect the scintillation light;
a setting unit configured to randomly set one detector from among the detectors as a first detector to be corrected;
an identifier configured to identify, out of the detectors, one or more second detectors, each detecting a synchronization signal synchronizing with a first signal detected by the first detector; and
a corrector configured to correct an energy spectrum of the scintillation light detected by the first detector on the basis of one or more second signals, each serving as the synchronization signal synchronizing with each of one or more first signals in signals detected by each of the second detectors, the first signals, and characteristic X-ray energy of a scintillator raw material constituting the scintillator layer, wherein
the corrector includes:
a first calculator configured to calculate, for each synchronization signal pair of the first signal and a second signal synchronizing with the first signal in a plurality of synchronization signal pairs, on the basis of a magnitude relation among a first energy corresponding to a wave height of the first signal, a second energy corresponding to a wave height of the second signal, and the characteristic X-ray energy, the first energy that is corrected to be treated as a value after correction and the number of signals allocated to the corrected first energy when an energy spectrum is calculated, and
a first corrector configured to correct the energy spectrum detected by the first detector using the corrected first energy corresponding to the first signal included in each of the synchronization signal pairs and the number of the signals, and

the identifier includes:
a first identifier configured to identify, out of the detectors, a first group of the second detectors that detect synchronization signals synchronizing with the first signals detected by the first detector;
a second calculator configured to calculate proportions of the second signals detected by the respective second detectors belonging to the first group;
a second identifier configured to identify a second group of the second detectors in each of which a reduction in proportion of the second signals is saturated, the proportions of the second signals being detected by the respective second detectors arranged in a direction apart from a location adjacent to the first detector being reduced; and
a third identifier configured to identify the second detectors not belonging to the second group out of the second detectors belonging to the first group as the detectors used for correction of the first signals.

2. The radiation detection device according to claim 1 , wherein the second signal is detected within a certain time from the detection of the first signal.

3. The radiation detection device according to claim 1 , wherein the first calculator identifies the first signal and the second signal as signals originally entering the second detector and sets the number of signals to be allocated to zero when the first energy and the second energy are not equal to the characteristic X-ray energy, when the first energy is less than the second energy, and when the first energy is less than a first threshold.

4. The radiation detection device according to claim 1 , wherein the first calculator identifies the first signal and the second signal as signals accidentally synchronized with each other, sets the first energy as the corrected first energy, and sets the number of signals to be allocated to one when the first energy and the second energy are not equal to the characteristic X-ray energy, when the first energy is less than the second energy, and when the first energy is equal to or more than a first threshold.

5. The radiation detection device according to claim 1 , wherein the first calculator identifies the first signal and the second signal as signals originally entering the first detector, sets an addition value of the first energy and the second energy as the corrected first energy, and sets the number of signals to be allocated to one when the first energy and the second energy are not equal to the characteristic X-ray energy, when the first energy is equal to or more than the second energy, and when the second energy is less than a first threshold.

6. The radiation detection device according to claim 1 , wherein the first calculator identifies the first signal and the second signal as signals accidentally synchronized with each other, and sets the first energy to the corrected first energy, and sets the number of signals to be allocated to one when the first energy and the second energy are not equal to the characteristic X-ray energy, when the first energy is equal to or more than the second energy, and when the second energy is equal to or more than a first threshold.

7. The radiation detection device according to claim 1 , wherein the first calculator identifies the first signal and the second signal as signals originally entering the second detector and sets the number of signals to be allocated to zero when the first energy is equal to the characteristic X-ray energy and the second energy is not equal to the characteristic X-ray energy.

8. The radiation detection device according to claim 1 , wherein the first calculator identifies the first signal and the second signal as signals originally entering the first detector, sets an addition value of the first energy and the second energy to the corrected first energy, and sets the number of signals to be allocated to one when the first energy is not equal to the characteristic X-ray energy and the second energy is equal to the characteristic X-ray energy.

9. The radiation detection device according to claim 1 , wherein the first calculator identifies that X rays enter either the first detector or the second detector and a characteristic X-ray generated in one detector, which the X-rays have entered, enters the other detector, and sets an addition value of the first energy and the second energy to the corrected first energy, and calculates a predetermined value less than one as the number of the signals to be allocated when the first energy and the second energy are equal to the characteristic X-ray energy.

10. The radiation detection device according to claim 1 , wherein the first corrector corrects the energy spectrum detected by the first detector by producing, as a corrected energy spectrum, an energy spectrum that is represented by the number of synchronization signal pairs, the corrected first energy corresponding to the first signal included in each of the synchronization signal pairs, the number of signals allocated to the corrected first energy, the number of signals excluding the first signal in the signals detected by the first detector, and energy corresponding to the wave heights of the signals excluding the first signal.

11. The radiation detection device according to claim 1 , wherein the corrector corrects the energy spectrum of the scintillation light detected by the first detector on the basis of the second signal out of signals detected by the second detector identified as a detector used for correction of the first signal, the first signal, and the characteristic X-ray energy of the scintillator raw material constituting the scintillator layer.

12. The radiation detection device according to claim 1 , wherein
the corrector includes a third calculator configured to calculate a correction rate, and
the first calculator calculates the f

Assignees

• Toshiba Kk

Inventors

• Fujii Keiko
• Kawata Go
• Hosono Yasuharu
• Miyazaki Kazunori
• Hasegawa Rei

Classifications

• G01T7/005 Primary

  calibration techniques (stabilization of spectrometer G01T1/40) · CPC title

• G01T1/2018

  Scintillation-photodiode combinations · CPC title

• G01T1/362

  with scintillation detectors · CPC title

• G01T1/20184 Primary

  Detector read-out circuitry, e.g. for clearing of traps, compensating for traps or compensating for direct hits · CPC title