Multiple-energy techniques in industrial computerized tomography

Conference · Wed Aug 01 04:00:00 EDT 1990

DOI:https://doi.org/10.1016/0963-8695(94)90411-1· OSTI ID:6607034

Schneberk, D; Martz, H; Azevedo, S

Considerable 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.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• Sponsoring Organization: DOE/DP
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6607034
• Report Number(s): UCRL-JC-103762; CONF-900791--2; ON: DE90017518
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420500 -- Engineering-- Materials Testing
440101* -- Radiation Instrumentation-- General Detectors or Monitors & Radiometric Instruments
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
CALCULATION METHODS
COMPUTERIZED TOMOGRAPHY
DENSITY
DIAGNOSTIC TECHNIQUES
EQUIPMENT
EXPLOSIVES
GLASS
IMAGE PROCESSING
INDUSTRY
MATERIALS
MATERIALS TESTING
MOCKUP
NONDESTRUCTIVE TESTING
PHANTOMS
PHYSICAL PROPERTIES
PROCESSING
RADIATION SOURCES
Radiation Instrumentation
Radiometric Instruments
STRUCTURAL MODELS
TESTING
TOMOGRAPHY
X-RAY EQUIPMENT
X-RAY SOURCES