794 K
12 pp.
 
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TitleMultiple-energy Techniques in Industrial Computerized Tomography
Author(s)Schneberk, D.; Martz, H.; Azevedo, S.
Publication DateAugust 01, 1990
Report NumberUCRL-JC-103762
Unique IdentifierACC0259
Other NumbersCONF-900791--2; Legacy ID: DE90017518; OSTI ID: 6607034
Research OrgLawrence Livermore National Laboratory (LLNL), CA (USA)
Contract NoW-7405-ENG-48
Sponsoring OrgUS Department of Energy, Office of Defense Programs (DOE/DP)
Other InformationReview of Progress in Quantitative NDE; 15-20 Jul 1990; La Jolla, CA (USA)
Subject440101 -- Radiation Instrumentation -- General Detectors or Monitors & Radiometric Instruments; 990200 -- Mathematics & Computers; 420500 -- Engineering -- Materials Testing; Computerized Tomography -- Calculation Methods; Materials -- Computerized Tomography; Density; Explosives; Glass; Image Processing; Industry; Nondestructive Testing; Phantoms; X-Ray Sources
KeywordsDiagnostic Techniques; Equipment; Materials Testing; Mockup; Physical Properties; Processing; Radiation Sources; Structural Models; Testing; Tomography; X-ray Equipment; Instrumentation Related to Nuclear Science and Technology
Related Web PagesNon-medical Uses of Computed Tomography and Nuclear Magnetic Resonance
AbstractConsiderable effort is being applied to develop multiple-energy industrial CT techniques for materials characterization. Multiple-energy CT can provide reliable estimates of effective Z (Z{sub eff}), weight fraction, and rigorous calculations of absolute density, all at the spatial resolution of the scanner. Currently, a wide variety of techniques exist for CT scanners, but each has certain problems and limitations. Ultimately, the best multi-energy CT technique would combine the qualities of accuracy, reliability, and wide range of application, and would require the smallest number of additional measurements. We have developed techniques for calculating material properties of industrial objects that differ somewhat from currently used methods. In this paper, we present our methods for calculating Z{sub eff}, weight fraction, and density. We begin with the simplest case -- methods for multiple-energy CT using isotopic sources -- and proceed to multiple-energy work with x-ray machine sources. The methods discussed here are illustrated on CT scans of PBX-9502 high explosives, a lexan-aluminum phantom, and a cylinder of glass beads used in a preliminary study to determine if CT can resolve three phases: air, water, and a high-Z oil. In the CT project at LLNL, we have constructed several CT scanners of varying scanning geometries using {gamma}- and x-ray sources. In our research, we employed two of these scanners: pencil-beam CAT for CT data using isotopic sources and video-CAT equipped with an IRT micro-focal x-ray machine source.
794 K
12 pp.
 
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