Radiation detection and discrimination device, radiation survey instrument, and method

• US 20020175291A1
• Filed: 04/06/2001
• Published: 11/28/2002
• Est. Priority Date: 04/06/2001
• Status: Abandoned Application

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Battelle Memorial Institute
• Inventors: Reeder, Paul L., Bowyer, Sonya M.
• Application Number:
  US09/828,316
• Publication Number:
  US 20020175291A1
• Time in Patent Office: Days
• US Class Current: 250/369
• CPC Class Codes: G01T 3/06 with scintillation detectors
• CPC Class Codes: G01T 7/00 Details of radiation-measuring instruments

Abstract

A radiation detection and discrimination device includes a radiation sensor and signal processing circuitry. The radiation sensor includes a LiBaF₃ scintillator configured to simultaneously detect presence of a first type of radiation and a second type of radiation. The radiation sensor generates an output signal for each type of detected radiation. The signal processing circuitry communicates with the sensor, and includes data analysis circuitry and memory. The signal processing circuitry is operative to receive at least one output signal from the sensor. The memory is operative to store at least one predetermined indicia characterizing membership of an output signal within a group comprising a unique type of radiation. The data analysis circuitry compares the output signal with the at least one predetermined indicia to determine membership of the output signal within one group of a plurality of unique groups. Each group comprises a unique type of radiation including the first type of radiation and the second type of radiation. A method is also provided.

Claims

1. A radiation detection and discrimination device, comprising:

a radiation sensor comprising a LiBaF₃ scintillator configured to simultaneously detect presence of a first type of radiation and a second type of radiation and generate an output signal for each type of detected radiation; and

signal processing circuitry communicating with the sensor including data analysis circuitry and memory, the signal processing circuitry operative to receive at least one output signal from the sensor;

wherein the memory is operative to store at least one predetermined indicia characterizing membership of an output signal within a group comprising a unique type of radiation, and wherein the data analysis circuitry compares the output signal with the at least one predetermined indicia to determine membership of the output signal within one group of a plurality of unique groups each comprising a unique type of radiation including the first type of radiation and the second type of radiation.

2. The device of claim 1 wherein the signal processing circuitry analyzes a pulse shape of the output signal comprising pulse amplitude versus time, wherein the at least one indicia comprises a histogram of pulse amplitude versus time, and wherein the data analysis circuitry compares the pulse shape of the output signal with the histogram to determine membership of the output signal within one group of a plurality of unique groups.

3. The device of claim 1 wherein the radiation sensor further comprises a photomultiplier (PM) tube communicating with the LiBaF₃ scintillator.

4. The device of claim 3 wherein the radiation sensor further comprises a thin, light-tight window configured to allow alpha particles to reach the scintillator.

5. The device of claim 1 further comprising a user interface communicating with the signal processing circuitry and operative to display detected presence of at least one of the first type of radiation and the second type of radiation.

6. The device of claim 5 wherein the user interface comprises a first display meter for displaying detected presence of the first type of radiation and a second display meter for displaying detected presence of the second type of radiation.

7. The device of claim 6 wherein the LiBaF₃ scintillator is configured to detect presence of a third type of radiation, wherein the plurality of unique groups each comprise a unique type of radiation including a third type of radiation, and wherein the user interface comprises a third display meter for displaying detected presence of the third type of radiation.

8. The device of claim 6 wherein the first type of radiation comprises alpha radiation and the second type of radiation comprises beta/gamma-ray radiation.

9. The device of claim 7 wherein the first type of radiation comprises thermal neutron radiation, the second type of radiation comprises fast neutron radiation, and the third type of radiation comprises beta/gamma-ray radiation.

10. The device of claim 1 wherein the signal processing circuitry is provided by electronics within a hand-held housing, and wherein the radiation sensor is remotely coupled with the housing via a flexible electrical cable.

12. The radiation survey instrument of claim 11 wherein the scintillation sensor comprises a LiBaF₃ scintillator configured to detect a plurality of unique types of radiation.

11. A radiation survey instrument, comprising:

a scintillation sensor of a single material capable of simultaneously detecting and discriminating a plurality of unique types of radiation and generating an output signal from a detected type of radiation; and

signal processing circuitry communicating with the sensor and operative to receive the generated output signal from the scintillation sensor and compare the output signal with a predetermined histogram of pulse amplitude versus time;

wherein the signal processing circuitry compares the pulse shape of the output signal with the histogram to determine membership of the output signal within an identified type of radiation from the plurality of unique types of radiation.

13. The radiation survey instrument of claim 12 further comprising a photomultiplier (PM) tube communicating with the LiBaF₃ scintillator.

14. The radiation survey instrument of claim 11 further comprising a portable housing configured to carry the signal processing circuitry.

15. The radiation survey instrument of claim 14 further comprising an electrical cable coupling the scintillation sensor with the housing to enable positioning of the sensor relative to the housing while conducting a radiation survey.

16. The radiation survey instrument of claim 15 wherein the signal processing circuitry comprises data analysis circuitry configured to analyze a pulse shape of the output signal and compare the pulse shape with at least one predetermined histogram.

17. The radiation survey instrument of claim 11 wherein the scintillation sensor comprises a window disposed in front of the single material and operative to enable alpha particles to reach the single material.

19. The method of claim 18 wherein the radiation detector comprises a LiBaF₃ scintillator configured to detect presence of a first type of radiation and a second type of radiation and generate corresponding output signals for each type of detected radiation.

20. The method of claim 19 wherein the first type of radiation comprises alpha radiation and the second type of radiation comprises beta/gamma-ray radiation.

21. The method of claim 18 wherein the scintillator is further configured to detect presence of a third type of radiation, and wherein the first type of radiation comprises thermal neutron radiation, the second type of radiation comprises fast neutron radiation, and the third type of radiation comprises beta/gamma-ray radiation.

22. The method of claim 18 wherein the first digital data set comprises a first reference pulse shape digital data set representative of a shape of a detection signal for the first type of radiation, and the second digital data set comprises a second reference pulse shape digital data set representative of a shape of a detection signal for the second type of radiation.

18. A method of simultaneously measuring for the presence of at least two unique types of radiation, comprising:

in a radiation detector, detecting the presence of one type of at least two types of radiation;

in response to detecting the one type of radiation, producing an output signal having a pulse shape comprising output pulse amplitude versus time;

storing a first digital data set representative of a first type of radiation and a second digital data set representative of a second type of radiation; and

comparing the output signal pulse shape of the one type of detected radiation with the first digital data set and the second digital data set to determine identification of the output signal pulse shape as either a first type of radiation or a second type of radiation.