# Physics-based, Bayesian sequential detection method and system for radioactive contraband

## Abstract

A distributed sequential method and system for detecting and identifying radioactive contraband from highly uncertain (noisy) low-count, radionuclide measurements, i.e. an event mode sequence (EMS), using a statistical approach based on Bayesian inference and physics-model-based signal processing based on the representation of a radionuclide as a monoenergetic decomposition of monoenergetic sources. For a given photon event of the EMS, the appropriate monoenergy processing channel is determined using a confidence interval condition-based discriminator for the energy amplitude and interarrival time and parameter estimates are used to update a measured probability density function estimate for a target radionuclide. A sequential likelihood ratio test is then used to determine one of two threshold conditions signifying that the EMS is either identified as the target radionuclide or not, and if not, then repeating the process for the next sequential photon event of the EMS until one of the two threshold conditions is satisfied.

- Inventors:

- Issue Date:

- Research Org.:
- LLNL (Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States))

- Sponsoring Org.:
- USDOE

- OSTI Identifier:
- 1127092

- Patent Number(s):
- 8,676,744

- Application Number:
- 12/259,198

- Assignee:
- Lawrence Livermore National Security, LLC (Livermore, CA)

- DOE Contract Number:
- AC52-07NA27344

- Resource Type:
- Patent

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY

### Citation Formats

```
Candy, James V, Axelrod, Michael C, Breitfeller, Eric F, Chambers, David H, Guidry, Brian L, Manatt, Douglas R, Meyer, Alan W, and Sale, Kenneth E.
```*Physics-based, Bayesian sequential detection method and system for radioactive contraband*. United States: N. p., 2014.
Web.

```
Candy, James V, Axelrod, Michael C, Breitfeller, Eric F, Chambers, David H, Guidry, Brian L, Manatt, Douglas R, Meyer, Alan W, & Sale, Kenneth E.
```*Physics-based, Bayesian sequential detection method and system for radioactive contraband*. United States.

```
Candy, James V, Axelrod, Michael C, Breitfeller, Eric F, Chambers, David H, Guidry, Brian L, Manatt, Douglas R, Meyer, Alan W, and Sale, Kenneth E. Tue .
"Physics-based, Bayesian sequential detection method and system for radioactive contraband". United States. https://www.osti.gov/servlets/purl/1127092.
```

```
@article{osti_1127092,
```

title = {Physics-based, Bayesian sequential detection method and system for radioactive contraband},

author = {Candy, James V and Axelrod, Michael C and Breitfeller, Eric F and Chambers, David H and Guidry, Brian L and Manatt, Douglas R and Meyer, Alan W and Sale, Kenneth E},

abstractNote = {A distributed sequential method and system for detecting and identifying radioactive contraband from highly uncertain (noisy) low-count, radionuclide measurements, i.e. an event mode sequence (EMS), using a statistical approach based on Bayesian inference and physics-model-based signal processing based on the representation of a radionuclide as a monoenergetic decomposition of monoenergetic sources. For a given photon event of the EMS, the appropriate monoenergy processing channel is determined using a confidence interval condition-based discriminator for the energy amplitude and interarrival time and parameter estimates are used to update a measured probability density function estimate for a target radionuclide. A sequential likelihood ratio test is then used to determine one of two threshold conditions signifying that the EMS is either identified as the target radionuclide or not, and if not, then repeating the process for the next sequential photon event of the EMS until one of the two threshold conditions is satisfied.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2014},

month = {3}

}

Works referenced in this record:

##
Method for characterizing samples of secondary light emitting particles

patent-application, May 2004

- Eggeling, Christian; Kask, Peet; Seidel, Claus
- US Patent Application 10/451653; 20040099813

##
Methods and apparatus for identifying subject matter in view data

patent-application, August 2006

- Mundy, JOseph L.; Kimia, Benjamin; Klein, Philip Nathan
- US Patent Application 11/299558; 20060182327

##
User Interface for use in Security Screening Providing Image Enhancement Capabilities and Apparatus for Implementing Same

patent-application, October 2008

- Gudmundson, Dan; Perron, Luc
- US Patent Application 11/694338; 20080240578

##
A probabilistic derivation of gamma-ray attenuation and application: Bayesian mass estimation with a low count spectrum

journal, December 2006

- Anderson, Dale N.; Hensley, Walter K.; Barnett, Debra S.
- Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 569, Issue 3, p. 894-899

##
Photon counting with silicon avalanche photodiodes

journal, January 1992

- Sun, X.; Davidson, F. M.
- Journal of Lightwave Technology, Vol. 10, Issue 8

##
Bayesian statistics in radionuclide metrology: measurement of a decaying source

journal, August 2007

- Bochud, François O.; Bailat, Claude J.; Laedermann, Jean-Pascal
- Metrologia, Vol. 44, Issue 4

##
Bayesian Processing for the Detection of Radioactive Contraband from Uncertain Measurements

conference, December 2007

- Candy, James V.; Sale, Kenneth; Guidry, Brian L.
- 2007 2nd IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing

##
A Bayesian sequential processor approach to spectroscopic portal system decisions

conference, September 2007

- Sale, K.; Candy, J.; Breitfeller, E.
- Optical Engineering + Applications, SPIE Proceedings

##
Timing estimation for a filtered Poisson process in Gaussian noise

journal, January 1991

- Hero, A. O.
- IEEE Transactions on Information Theory, Vol. 37, Issue 1

##
Bayesian estimation of state-space models applied to deconvolution of Bernoulli—Gaussian processes

journal, March 1997

- Doucet, Arnaud; Duvaut, Patrick
- Signal Processing, Vol. 57, Issue 2, p. 147-161

##
An inter-comparison of three spectral-deconvolution algorithms for gamma-ray spectroscopy

journal, January 2000

- Meng, L. J.; Ramsden, D.
- IEEE Transactions on Nuclear Science, Vol. 47, Issue 4

##
Bayesian deconvolution of noisy filtered point processes

journal, January 2001

- Andrieu, C.; Barat, E.; Doucet, A.
- IEEE Transactions on Signal Processing, Vol. 49, Issue 1

##
Pulse-height spectrum measurement experiment for code benchmarking: Initial results

conference, January 2001

- Sale, K. E.
- The CAARI 2000: Sixteenth international conference on the application of accelerators in research and industry, AIP Conference Proceedings

##
Bayesian model selection and parameter estimation of nuclear emission spectra using RJMCMC

journal, February 2003

- Gulam Razul, S.; Fitzgerald, W. J.; Andrieu, C.
- Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 497, Issue 2-3

##
A tutorial on particle filters for online nonlinear/non-Gaussian Bayesian tracking

journal, January 2002

- Arulampalam, M. S.; Maskell, S.; Gordon, N.
- IEEE Transactions on Signal Processing, Vol. 50, Issue 2

##
Background removal from spectra by designing and minimising a non-quadratic cost function

journal, April 2005

- Mazet, Vincent; Carteret, Cédric; Brie, David
- Chemometrics and Intelligent Laboratory Systems, Vol. 76, Issue 2, p. 121-133

##
Sequential probability ratio test for long-term radiation monitoring

conference, January 2003

- Jarman, K. D.; Smith, L. E.; Carlson, D. K.
- 2003 IEEE Nuclear Science Symposium. Conference Record (IEEE Cat. No.03CH37515)

##
Monte Carlo methods for signal processing: a review in the statistical signal processing context

journal, November 2005

- Doucet, A.
- IEEE Signal Processing Magazine, Vol. 22, Issue 6

##
An Overview of Existing Methods and Recent Advances in Sequential Monte Carlo

journal, May 2007

- Cappe, Olivier; Godsill, Simon J.; Moulines, Eric
- Proceedings of the IEEE, Vol. 95, Issue 5