High resolution gamma ray tomography scanner for flow measurement and non-destructive testing applications

Abstract

We report on the development of a high resolution gamma ray tomography scanner that is operated with a Cs-137 isotopic source at 662 keV gamma photon energy and achieves a spatial image resolution of 0.2 line pairs/ mm at 10% modulation transfer function for noncollimated detectors. It is primarily intended for the scientific study of flow regimes and phase fraction distributions in fuel element assemblies, chemical reactors, pipelines, and hydrodynamic machines. Furthermore, it is applicable to nondestructive testing of larger radiologically dense objects. The radiation detector is based on advanced avalanche photodiode technology in conjunction with lutetium yttrium orthosilicate scintillation crystals. The detector arc comprises 320 single detector elements which are operated in pulse counting mode. For measurements at fixed vessels or plant components, we built a computed tomography scanner gantry that comprises rotational and translational stages, power supply via slip rings, and data communication to the measurement personal computer via wireless local area network.

Liquid flow texture analysis in trickle bed reactors using high-resolution gamma ray tomography

“…The spatial resolution of the system is about 0.2 line pairs mm −1 . Further details concerning the detector and tomograph design are given by Bieberle et al [27] and by Hampel et al [28].…”

Gamma-ray-based measurement of concentration distribution in pipe flow of settling slurry: vertical profiles and tomographic maps

“…The number of sources and detectors can be reduced if those are allowed to rotate round the measuring volume (e.g. Hampel et al, 2007;Lee et al, 2009). One source and one detector only can be also employed to provide tomographic data provided that their linear and radial shifting is allowed and combined.…”

Construction and Test of Low Cost X-Ray Tomography Scanner for Physical-Chemical Analysis and Nondestructive Inspections

“…CT methods have been used in many areas in recent years such as: application in soil science [2], study of porous structure of amorphous materials [3], etc. Since the presentation of the medical tomography, a great number of scanners have been projected and constructed [4,5]. Our project has some similarity from that proposed by Naime [6], since we use the same kind of radiation detection.…”