Multifaceted radiation detection and classification system

Patent metadata

Field	Value
Publication number	US-11513253-B2
Application number	US-202117184171-A
Country	US
Kind code	B2
Filing date	Feb 24, 2021
Priority date	May 18, 2018
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

A system identifying a source of radiation is provided. The system includes a radiation source detector and a radiation source identifier. The radiation source detector receives measurements of radiation; for one or more sources, generates a detection metric indicating whether that source is present in the measurements; and evaluates the detection metrics to detect whether a source is present in the measurements. When the presence of a source in the measurements is detected, the radiation source identifier for one or more sources, generates an identification metric indicating whether that source is present in the measurements; generates a null-hypothesis metric indicating whether no source is present in the measurements; evaluates the one or more identification metrics and the null-hypothesis metric to identify the source, if any, that is present in the measurements.

First claim

We claim:

1. A method performed by a computing system for estimating a background histogram of background counts based on measurement histograms of measurement counts of measurements collected to detect presence of a source reflected within the measurements, the method comprising:
accessing basis vectors of histograms that span a linear combination of prior background histograms derived from prior measurement histograms;
calculating a current background histogram based on the current measurement histograms;
determining whether the current background histogram has at least a specified degree of association with or disassociation with a basis vector;
upon determining that the current background histogram has at least a specified degree of association with or disassociation with a basis vector, modifying the basis vectors based on the current background histogram;
after modifying the basis vectors, adjusting the basis vectors to increase diversity;
computing a background radiation based on the basis vectors; and
detecting a source of radiation based on the computed background radiation.

2. The method of claim 1 wherein the adjusting attempts to maximize eigenvalues associated with a correlation matrix formed by the basis vectors.

3. The method of claim 1 further comprising applying a detection algorithm to detect presence of the source in a target measurement factoring the adjusted basis vectors.

4. The method of claim 1 wherein the source is a source of radiation.

5. The method of claim 1 wherein the prior measurement histograms are predefined histograms.

6. The method of claim 1 wherein the prior measurement histograms include histograms collected during a same collection process as and prior to generating the current measurement histogram.

7. The method of claim 1 wherein the prior measurement histograms not collected during the same collection process.

8. One or more computing systems for estimating a background spectral shape of background counts based on measurement spectral shapes of measurements collected to detect presence of a source spectral shape of a source within the measurements, the one or more computing systems comprising:
one or more computer-readable storage mediums for storing computer-executable instructions for controlling the one or more computing systems to:
access basis vectors that span a linear combination of prior background spectral shapes derived from prior measurement spectral shapes;
calculate a current background spectral shape for a sequence of current measurement spectral shapes;
determine whether the current background spectral shape has at least a specified degree of association with or disassociation with a basis vector;
upon determining that the current background spectral shape has the specified degree of association with or disassociation with a basis vector, modify that basis vector based on the current background spectral shape;
after modifying that basis vector, adjust the basis vectors to increase diversity;
computing a background radiation based on the basis vectors; and
detecting a source of radiation based on the computed background radiation; and

one or more processors for executing the computer-executable instructions stored in the one or more computer-readable storage mediums.

9. The one or more computing systems of claim 8 wherein instructions that adjust attempt to maximize eigenvalues association with a correlation matrix formed by the basis vectors.

10. The one or more computing systems of claim 8 wherein the instructions further apply a detection algorithm to detect presence of the source in a target measurement factoring the adjusted basis vectors.

11. The one or more computing systems of claim 8 wherein the source is a source of radiation.

12. The one or more computing systems of claim 8 wherein the prior measurement histograms are predefined histograms.

13. The one or more computing systems of claim 8 wherein the prior measurement spectral shapes include spectral shapes collected during a same collection process and prior to generating the current measurement spectral shape.

14. The one or more computing systems of claim 8 wherein the prior measurement spectral shapes are not collected during the same collection process.

15. The one or more computing systems of claim 8 wherein the computer-executable instructions include instructions to suppress the modifying of the basis vector and updating the basis vectors when the background measurements do not change for a duration.

16. The one or more computing systems of claim 8 wherein the background measurements are queued until there is a change in the spectral shape of a background measurement.

17. The one or more computing systems of claim 8 wherein the background measurements are queued until a minimum time has elapsed.

18. The one or more computing systems of claim 8 wherein the spectral shapes are represented by histograms.

Assignees

• L Livermore Nat Security Llc

Inventors

• Labov Simon E
• Nelson Karl E
• Seilhan Brandon S

Classifications

• G01T1/167

  Measuring radioactive content of objects, e.g. contamination (whole body counters G01T1/163) · CPC title

• G01T1/36

  Measuring spectral distribution of X-rays or of nuclear radiation {spectrometry (pulse selection circuits per se H03K; investigation of materials by radiation diffraction G01N23/20; spectrometer tubes H01J49/00)} · CPC title

• G01T7/00 Primary

  Details of radiation-measuring instruments · CPC title

• G01V5/0075 Primary

  Physics · mapped topic

• G01V5/0091

  Physics · mapped topic