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Title: Identification of Radioactive Materials by Analysis of Simulations and Measurements of Cross-Correlation Functions

Abstract

A fast and robust methodology for identification of radioactive materials is of great interest for applications in the fields of homeland security and nuclear nonproliferation. For fissile materials in particular, several passive and active interrogation techniques are being investigated. These systems rely on the fact that the interrogated material emits correlated neutrons and gamma rays from each induced or spontaneous fission event. A convenient way to look at correlated events in a fissionable material is to study time-dependent detector cross-correlation functions. These functions are unique for a given material and geometry, representing a distinctive signature of the material-geometry configuration. In this work, we focus on the identification of plutonium samples in both metallic and oxide form. The simulation program used in this study is the MCNP-PoliMi code, an improved version of the standard MCNP code. This code allows the user to obtain event-by-event information about the simulated particles. This capability is essential for accurate simulations of cross-correlation events. The number of correlated events as a function of time is obtained from the MCNP-PoliMi output collision file by using appropriate postprocessing algorithms. We investigated several parameters, such as the sample composition and mass, the sample-detector distance, and the shielding between themore » detector and the sample. We then analyzed the simulated cross correlation functions to obtain relationships between features from the correlations and sample characteristics. To verify the simulations, the measured correlation function was compared with the simulated one.« less

Authors:
 [1];  [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
Work for Others (WFO)
OSTI Identifier:
932071
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Conference
Resource Relation:
Conference: INMM 48th Annual Meeting, Tucson, AZ, USA, 20070708, 20070712
Country of Publication:
United States
Language:
English
Subject:
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; CORRELATION FUNCTIONS; FISSILE MATERIALS; FISSIONABLE MATERIALS; RADIOACTIVE MATERIALS; SPONTANEOUS FISSION; SIMULATION

Citation Formats

Flaska, Marek, and Pozzi, Sara A. Identification of Radioactive Materials by Analysis of Simulations and Measurements of Cross-Correlation Functions. United States: N. p., 2007. Web.
Flaska, Marek, & Pozzi, Sara A. Identification of Radioactive Materials by Analysis of Simulations and Measurements of Cross-Correlation Functions. United States.
Flaska, Marek, and Pozzi, Sara A. Mon . "Identification of Radioactive Materials by Analysis of Simulations and Measurements of Cross-Correlation Functions". United States. doi:.
@article{osti_932071,
title = {Identification of Radioactive Materials by Analysis of Simulations and Measurements of Cross-Correlation Functions},
author = {Flaska, Marek and Pozzi, Sara A},
abstractNote = {A fast and robust methodology for identification of radioactive materials is of great interest for applications in the fields of homeland security and nuclear nonproliferation. For fissile materials in particular, several passive and active interrogation techniques are being investigated. These systems rely on the fact that the interrogated material emits correlated neutrons and gamma rays from each induced or spontaneous fission event. A convenient way to look at correlated events in a fissionable material is to study time-dependent detector cross-correlation functions. These functions are unique for a given material and geometry, representing a distinctive signature of the material-geometry configuration. In this work, we focus on the identification of plutonium samples in both metallic and oxide form. The simulation program used in this study is the MCNP-PoliMi code, an improved version of the standard MCNP code. This code allows the user to obtain event-by-event information about the simulated particles. This capability is essential for accurate simulations of cross-correlation events. The number of correlated events as a function of time is obtained from the MCNP-PoliMi output collision file by using appropriate postprocessing algorithms. We investigated several parameters, such as the sample composition and mass, the sample-detector distance, and the shielding between the detector and the sample. We then analyzed the simulated cross correlation functions to obtain relationships between features from the correlations and sample characteristics. To verify the simulations, the measured correlation function was compared with the simulated one.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}

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