Radiation measurement device

Patent metadata

Field	Value
Publication number	US-9759819-B2
Application number	US-201314892969-A
Country	US
Kind code	B2
Filing date	Dec 16, 2013
Priority date	Aug 8, 2013
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

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.

First claim

The invention claimed is:

1. A radiation measurement device comprising a calculation unit 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, wherein the calculation unit, 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, and based on an energy resolution of the radiation detector, corrects a dose by calculating a portion thereof neglected as what is the same as or smaller than a measurement limit, so as to calculate a dose of a radiation that has entered the radiation detector, wherein the dose of the radiation to be calculated is a dose rate that is a dose per unit time.

2. The radiation measurement device according to claim 1 , wherein the calculation unit comprises:
a spectrum generation unit that generates the wave height spectrum;
a dose rate calculation unit that calculates a dose in the radiation energy value corresponding to each of the channels, based on a count generated in each channel by the spectrum generation unit, that integrates the calculated dose for the whole measurement range for the radiation energy value so as to obtain an integral dose, and that divides the integral dose by a measurement time so as to obtain a dose rate;
a correcting dose rate calculation unit that calculates a dose neglected as what is the same as a measurement limit or smaller, based on a count in at least one channel that includes the lower limit within a measurement range for the radiation energy value, out of counts generated in the respective channels by the spectrum generation unit, and based on the energy resolution of the radiation detector, obtains a correcting dose rate, that is a dose per unit time, from the calculated dose; and
a dose rate correction calculation unit that corrects the dose rate obtained by the dose rate calculation unit, by use of the correcting dose rate obtained by the correcting dose rate calculation unit, and that calculates a dose rate of a radiation that has entered the radiation detector.

3. The radiation measurement device according to claim 1 , wherein the radiation detector is a scintillation detector.

4. The radiation measurement device according to claim 1 , wherein the calculation unit, based on a count in at least one channel within the measurement range for the radiation energy value, corrects a distortion in an energy characteristic of the radiation detector caused by variations in the linearity of the wave height in response to the energy of a radiation so as to calculate a dose of a radiation that has entered the radiation detector.

5. The radiation measurement device according to claim 1 , wherein the radiation detector is a semiconductor radiation detector.

6. The radiation measurement device according to claim 5 , wherein a radiation enters the radiation detector through a physical filter for compensating an energy characteristic of the radiation detector.

Assignees

• Mitsubishi Electric Corp

Inventors

• Eguchi Kazuhiro
• Moteki Kenichi

Classifications

• G01T1/2006 Primary

  using a combination of a scintillator and photodetector which measures the means radiation intensity · CPC title

• G01T1/40

  Stabilisation of spectrometers · CPC title

• G01T1/02

  Dosimeters (G01T1/15 takes precedence) · CPC title