Assessment of Thermal Neutron Activation Applied to Surface and Near Surface Unexploded Ordnance
Abstract
Thermal neutron activation (TNA) has been proposed for confirming the presence of energetic materials as part of a mine or unexploded ordnance detection system. SAIC, funded through the Night Vision Electro-Sciences Directorate by the Environmental Security Test Certification Program, has carried out proof of concept demonstrations of TNA in this confirmatory role at Socorro, NM, and at Yuma, AZ. In this paper, we present a description of the phenomenology of TNA, an analysis of the performance of the SAIC system, and suggestions for hardware upgrades to improve current performance. Our analysis includes the development of a semi-empirical model for the expected signal strength as a function of the target's nitrogen content and depth. We expect this simple model to be useful in future assessments of the feasibility of this approach. We also calculate the Pd/PFA performance of the system at the two sites and determine it to correspond to a signal to noise ratio (or figure-of-merit) of order unity. We estimate that an increase in signal to noise of roughly 10 will be necessary to make this technology applicable for unexploded ordnance and mine detection. Such order-of-magnitude improvements may be possible if the NaI detectors currently employed are replaced with high purity germanium (HPGe) detectors.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1997
- Accession Number
- ADA339221
Entities
People
- David A. Sparrow
- Lisa M. Porter
Organizations
- Institute for Defense Analyses