- Email: [email protected]
Development of a neutron-radiographic technique for investigating physical models of fluidized beds
Several resolution functions are analysed in order to describe the unsharpness of knife-edge images. Comparisons are done with the definition of unsharpness by various authors. The suitablity of a resolution function is assessed according to its fit to the data from measured densities. Investigations of the dyprosium transfer method, the track etch technique and the Gadolinium direct method were conducted in each case distinguishing between inherent and geometrical ansharpness. 38815
Windsor, C.G.
The nature of the scattering process in small angle neutron scattering United Kingdom Atomic Energy Authority, Harwell, A E R E - M P D NBS-342, 16 pp. (May 1988) Neutron and X-ray small angle scattering provide, along with electron microscopy and diffraction, the principal tools for the microscopic characterisation of materials. Neutron, X-ray and electron beams have quite different properties. In fact, each has unique advantages. The penetration of neutrons through most materials is responsible for many of its applications. The ever increasing intensity of available X-ray beams is opening new fields. The advantage of electron beams is their ability to work in both real and reciprocal space. The problems of transforming the results of an experiment in reciprocal space to give an interpretation in real space are central to small angle scattering, and will be discussed in detail. Several examples will be given of the successful use of small angle neutron and X-ray scattering applied to problems where other techniques have failed to make a decisive contribution. 38812
Heidt, H.; Stade, J.
State and prospects of industrial neutron radiography in Germany (In
German) Materialprnfung, Vol. 30, No. 5, pp. 137-139 (May 1988) Although the first neutron radiographies in Germany were made nearly 50 years ago, this nondestructive testing method has not yet been widely used in industry. The main reason is the lack of mobile, intensive and low-cost neutron sources. Another important aspect is the availability of real-time inspection systems equipped with neutron image amplifiers which will accelerate the test and permit to represent dynamic processes. New applications for mobile neutron sources may be expected in aircraft inspection, in testing fibre-reinforced plastics, in different types of ceramic materials, in the building sector, in corrosion protection as well as with various problems encountered with lubrication agents.
38807 Pekarskii, G.Sh. Neutron backscattering nondestructive-test instruments Soviet Journal of Nondestructive Testing, Vol. 23, No. 7, pp. 512-515 (Mar. 1988) Calculations and measurements are used to make recommendations for neutron nondestructive testing and radioisotope automatic devices operating with one-sided access. Emphasis is placed on optimizing the major components for particular industrial purposes. Operating characteristics are given for various instruments: thickness gauges, level gauges, and means of detecting blocking points in pipe-lines, etc. 38625
McCauley, J. W.
NDT: Clearing the reliability bottleneck Ceramic Industry, Vol. 130, No. 3, pp. 33-34 (Mar. 1988) Nondestructive testing will play an important role in both the production of ceramic parts and flaw detection to improve their present low reliability, as they are more widely used in industry. A wide variety of nondestructive testing techniques, appropriate to different ceramic problems are listed, with ultrasonic, radiography, optical methods and neutron scattering being of most benefit for both green- state and sintered ceramics. 38526
Panakkal, J.P.; Ghosh, J.K.
A simple model for neutron radiography of uranium-plutonium mixed oxide fuel pins Journal of Nuclear Materials, Vol. 153, No. 1-3, pp. 82-85 (Apr. 1988) Neutron radiography has been used for monitoring plutonium enrichment in uranium-plutonium mixed oxide fuel pellets, inside welded nuclear fuel pins, by correlating the optical density of radiographs at the centre of the pellets and plutonium enrichment. Optical density data corresponding to different thicknesses of the pellets starting from the centre towards the periphery was generated by microdensitometer scanning of neutron radiographs of the experimental fuel pins. An attempt has been made to correlate the optical density at points corresponding to different thickness segments of the pellets and thermal neutron interaction probability (product of the total macroscopic neutron cross section and the distance traversed by the neutrons). Based on the experimental data generated, a simple model for transmission of neutrons through nuclear fuel pins has been evolved. Using this model, it is possible to predict the optical density of plutonium bearing fuel pins containing pellets of different composition or diameter in neutron radiographic investigations. 38517
Ratcliffe, B.J.
Investigation into the use of track-etch imaging to produce neutron radiographs from a non-reactor neutron source British Journal of Nondestructive Testing, Vol. 30, No. 3, pp. 183-188 (May 1988) A study is described of the use of cellulose nitrate with an enriched boron-10 converter screen for producing neutron radiographs from a RARDE non-reactor neutron assembly. Investigation into the required exposure and etching times has been made together with the measurement of unsharpnesses. The study shows that track-etching gives a sharper image than that obtained with
NDT International August 1989
the dysprosium transfer technique and the image is available for viewing in a much shorter time.
Lambrineas, P.; Finlayson, T.R.; Griffiths, J.R.; Howard, C.J.; Smith, T.F.
38220
Neutron diffraction residual stress measurements on a thin steel plate N D T International, Vol. 20, No. 5, pp. 285-290 (Oct. 1987) Residual stress measurements are made on a thermally stressed steel plate (4 mm thick) by using neutron diffraction. The sin/sup 2/psi technique, commonly employed to measure residual stresses by using X- ray diffraction, is applied to show that the stresses are biaxial, lying within the plane of the plate, and to evaluate the magnitude of the stresses. Measurements are made in both transmission and reflection geometries. Stress measurements made in a particular sample orientation are reproducible to within + - 10 MPa. The principal stresses determined from a series of such measurements have an uncertainty of + - 30 MPa, which is comparable to the + - 20 MPa commonly quoted for the X-ray sin/sup 2/psi technique. 38217 Brenizer, J.S.; Tobin, K.W.; Hylko, J.M.; McRae, D.D.; Jenkins, R.W. Jr. Quantitative measurement of equivalent water density in a burning
cigarette Materials Evaluation, Vol. 45, No. 11, pp. 1310-1314 (Nov. 1987) As a result of an ongoing attempt to quantify the deposition of hydrogenous compounds along the axial direction of a burning cigarette, software has been developed that takes into account the statistical nature of the neutron imaging system. This allows small variations in pixel luminance to be recorded in real time during the burn and correlated to an equivalent water density. The data collection process is based on spatial grouping of pixel locations within the rod as well as a time-averaged input of these discrete pixel groups. Once the system has been calibrated, a cigarette is positioned in the neutron beam. The area of interest is then divided into ten equal parts. All the pixel luminances in an area are averaged into one representative luminance value. As the cigarette burns, these areas are simultaneously sampled. A statistical analysis is performed for the real-time averages, and the data are stored in a file for later analysis. 38212
Ratcliffe, B.J.
Development of a non-reactor neutron radiographic assembly using a 12 MeV linear electron accelerator British Journal of Nondestructive Testing, Vol. 30, No. 2, pp. 94-98 (Mar. 1988) A description is given of the development of a neutron radiography assembly which does not use a nuclear reactor. The neutron radiographic technique developed can in some circumstances detect explosive in metal ordnance with a greater sensitivity than X- radiography. 38211
Mayers, J.; Baciocco, G.; Hannon, A.C.
Temperature measurement by neutron resonance radiography Rutherford Appleton Laboratory, Didcot (United Kingdom), RAL-88-017, 14 pp. (Mar. 1988) We present a new data analysis technique for obtaining temperatures from neutron resonance radiography measurements. The technique is applied to measurements on tantalum and rhenium foils, a high temperature engineering alloy and a model catalytic system. Temperatures have been obtained to an accuracy of better than + - 1 C in the temperature range 21 C to 600 C. The results, are in good agreement with theoretical simulations. 38210
Orphan, V.J.; Maung, T.
Robotic aircraft scanner for neutron radiographic inspection Proceedings of the 35th Conference on Remote Systems Technology, Los Angles, California (United States), Nov. 1987. pp. 195-199 American Nuclear Society, 1988. A robotic positioner and manipulator, a key component of a Mobile Neutron Radiography System (MNR) for aircraft inspection, is described. The MNRS is designed to inspect military aircraft for hidden corrosion in aluminum structures. MNRS is comprised of an accelerator-based (Kaman A-711 sealed-tube neutron generator using the D-T reaction) thermal neutron source, electronic neutron imaging system, robotic positioner and manipulator for the source/imager, control trailer housing system control electronics and digital image processing system, mobile dark room for film processing, a self-contained electrical power source and a radiation safety system. For in situ aircraft inspection, the Robotic Scanner is programmed (in a teach-learn mode) to scan a region of the components (e.g., wings, stabilizers, etc.) using a control pendant. 38209 Beynon, T.D.; Constantine, G. Deep penetration radiography using 24.5 keY neutrons Nuclear Instruments and Methods in Physics Research, Vol. A264, No.2/3, pp. 526-527 (15 Feb. 1988) A series of experiments is described which demonstrates how neutrons from the natural iron filter on the Harwell PLUTO reactor can radiograph objects through 152 mm of mild steel. 38202 Catchen, G.L.; Hughes, D.E.; Kulkarni, A.K.; Ross, K.M.; Ammerman, W.R.
Development of a neutron-radiographic technique for investigating physical models of fluidized beds Chemical Engineering Communications, Vol. 54, No. 1-6, pp. 73-84 (1987)
243
This paper describes the results of the application of neutron radiography to the study of a two-phase medium, and the resulting technique can be extended to the study of two-phase flow in a fluidized bed. Neutron radiography allows the nonintrusive visualizationof a sand/air bed enclosed in aluminum walls. This capability exceeds findings using conventional optical or radiographic techniques. A static 15 cm thick sand model was constructed and examined by the radiographic technique. The technique employed a collimated thermal column of neutrons, an image intensifier, and conventional photography. To simulate a fluidized bed, spherical voids of several centimeters in diameter were created by placing thin-walled empty aluminum shells in the sand bed. Also, hollow tubes were inserted in the bed. As a function of neutron flux, high contrast images of the voids inside the 15 cm thick bed were obtained and analyzed. This technique can be extended to the study of dynamic beds by using the neutron source, i.e. the nuclear reactor, in the pulsed mode.
Shuford, R.J.; Murray, T.J. Jr.; Bostic, M.T.; Brockelman, R.H.; Hinton, Y.L. 38016
Evaluation of nondestructive evaluation techniques for detecting moisture in composite materials l l t h World Conference on Nondestructive Testing, Las Vegas, Nevada (Un ited States), 3-8 Nov. 1985. Vol. 2, pp. 1366-1373. Taylor Publishing Co., Dallas (1985). Fiber reinforced organic matrix composites are being used or proposed as primary and secondary structures for numerous military and commercial applications. The structural behavior of these advanced materials are known to be affected by in-service environmental conditions (humidity, temperature, etc.). Absorbed moisture causes the matrix to swell, lowers the glass transition temperature of the resin (plasticization), induces residual stresses and microcracking in the composite, and can irreversibly degrade the fiber/matrix interface. In addition, moisture in prepregs (caused by improper storage) can change the curing behavior and degrade the physical and mechanical properties of the fabricated composite. This paper describes an on-going investigation to develop and evaluate practical NDE techniques for monitoring moisture in fiber reinforced epoxy resin prepregs and composites. NDE techniques being studied include: pulsed NMR, infrared thermography, ultrasonics, DC resistance, microdielectrometry, neutron radiography and acoustic emission. 37896
Maier, P.; Pfister, G.; Stier, G.; Kegreiss, W.; Hehn, G.
Progress in neutron tomography for non-destructive testing Neutr on Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 771-782. D. Reidel Publishing Company A neutron computer tomography scanner was developed and constructed using portable equipment and different neutron sources. Further studies will be done with cf-252 neutrons and fission neutrons from a nuclear reactor. Since each neutron source contains gamma radiation as well simultaneous neutron and a gamma $computer tomograph (CT) images are possiblel. In non-destructive material testing, fast neutrons can be used to examine thick metallic samples or to show small differences in the concentration of light nuclei. Several image reconstruction algorithms are available for samples with different size and material composition. A spatial resolution of 0.5 mm and a density resolution of about 5% could be achieved with the first CT images with fast neutrons. Neutron CT images show few artifacts compared to x-ray scans. Therefore the neutron CT technique can be used with advantage to examine strongly inhomogenous samples. Up to now the single beam technique has been used for all measurements. The Fanbeam technique is under study to reduce the measuring time. 37895
Froom, D.A.; Barton, J.P.
Plans for aircraft maintenance neutron radiography systems Neutron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 431-438. D. Reidel Publishing Company This paper outlines the key steps taken in the acquisition process, including design and specifications, for two neutron radiography systems for the inspection of removed aircraft components. 37894 Fufine, S.; Yoneda, K.; Kanda, K. Digital image processing for real-time neutron radiography Neutr on Radiography, Proceedings of ~the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. ~537-546. D. Reidel Publishing Company The real-time neutron radiography system of Kyoto University Research Reactor Institute (KURRI) has been used to identify the Location of burnable poison in the side plates of MTR type reactor fuel and to investigate moving objects, and also for neutron computed tomography. This paper describes several image processing techniques such as image integration, adaptive smoothing and image enhancement for real-time neutron radiography. 37893
Cocking, S.J.; Harris, D.H.C.
Robust equipment for dynamic neutron fluoroscopy Neutr on Radiograp hy, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 527-536. D. Reidel Publishing Company Compact and reliable equipment for dynamic neutron fluoroscopy has been developed and used in inspection tasks. The equipment is based on a zinc sulphide-lithiumfluoride composite neutron fluorescent screen and is viewed by a silicon intensifier target television camera. The real time image can be recorded with a standard video recorder and definition enhanced using a digital
244
image processor. Using a cold neutron beam at the D100 reactor, well contrasted image features of 1 mm dimension moving at 3 cm/sec can be readily observed. 37892
McClellan, G.C.; Tow, D.M.
Neutron tomography of damaged reactor fuel assemblies Neutron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 711-718. D. R e i de l Publishing Company A neutron tomography capability has been developed at Argonne National Laboratory Hot Fuel Examination facility for use in the NDE of reactor fuel assemblies, including those deliberately damaged to simulate accident conditions. Following in-reactor testing, the damaged fuel assemblies are transferred to the HFEF Neutron Radiography (NRAD) Facility, which was designed and equipped to perform high quality thermal and epithermal neutron radiography of a wide variety of irradiated materials. Indium-resonance radiographs are made of the damaged fuel assembly at many angles and over the full length of the fuel region. The resulting radiographs are then digitised, and the data are transmitted to EG and G Idaho computer laboratory for reconstruction into cross-sectional views of the fuel assembly. 37891
Ma Zhenze.
A neutron radiographic facility on a research reactor and some results obtained in NDT Neutron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 79-86. D. Reidel Publishing Company The characteristics of a neutron radiographic reactor facility are briefly described. Some performance indicators of the system such as resolution and sensitivity have been experimentally tested. Some practical applications of the facility and results obtained in the quality assurance and control of several industrial products are illustrated.
Mo Da-Wei; Liu Yi-Si; Guo Zhi-Ping; An Fu-Liu; Zhang Ghao-Zong; Miao Qi- Tian.
37890
Neutron radiography study in Tsinghua University N e ut ron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 87-94. D. R e i de l Publishing Company Neutron radiography research described in this paper was performed at the research reactor of Tsinghua University, which is a pool-type light water reactor with a power of 2 MW. Work carried out included the development of neutron radiographic convertors, neutron radiography of corn roots growing in soil and an investigation of water permeation in concrete. A preliminary real-time neutron radiography system which can be used to observe two-phase flow was installed. 37889
Zhou Yongmao; Wu Fuxing; Gu Deming.
The miniature neutron source reactor (MNSR) a private nuclear tool Neutron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 95-102. D. Reidel Publishing C ompa ny This paper describes the development and applications of a prototype Minature Neutron Source Reactor (MNSR). A new commercial MNSR has been designed based on the experience gained with the prototype. The new reactor offers improved performance and an extension of the neutron radiographic facility.
Kobayashi, H.; Harasawa, S.; Tomura, K.; Takami, Y.; Shiraishi, F.; Hattori, M.; Nagahara, T.; Matsuura, T.; Ogawa, 1.," Yamamoto, Y. 37888
Neutron radiography at Rikkyo Triga-ll Reactor Neutron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 129-136. D. Reidel Publishing Company A vertical diverging collimator has been installed in the reactor tank of Rikkyo 100 kW TRIGA-II reactor. The configuration of the collimator and the beam characteristics are summarized. The sensitivityand beam purity indicators have shown that the collimator can be considered as category I. Inherent lack of sharpness for the combination of the 25 micron Gd screen and the KODAK-SR film is determined experimentally and found to be 48.0 + - 0.5 microns. One application is the inspection of mold cavities in carburetors. 37887
Matsurnoto, T.; Aizawa, 0.; Watanabe, S.
Development of a neutron radiography system at the Musashi Institute of Technology Research Reactor Neutron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 137-144. D. Reidel Publishing Company A neutron radiography (NRG) facility has been designed and installed at one of the horizontal beam ports attached to the Musashi Institute of Technology Research Reactor. An X-ray radiographic apparatus using a portable generator was also equipped for comparison with the NRG. Various combinations of convertors and X-ray films were evaluated in order to obtain a high-quality radiography. A real-time NRG has also been installed for the investigation of moving objects and for the study of neutron computed tomography (NCT). A high-quality radiographic image was obtained by an image orthicon camera and a digital processing system.
NDT International August 1989
Windsor, C.G.
The nature of the scattering process in small angle neutron scattering United Kingdom Atomic Energy Authority, Harwell, A E R E - M P D NBS-342, 16 pp. (May 1988) Neutron and X-ray small angle scattering provide, along with electron microscopy and diffraction, the principal tools for the microscopic characterisation of materials. Neutron, X-ray and electron beams have quite different properties. In fact, each has unique advantages. The penetration of neutrons through most materials is responsible for many of its applications. The ever increasing intensity of available X-ray beams is opening new fields. The advantage of electron beams is their ability to work in both real and reciprocal space. The problems of transforming the results of an experiment in reciprocal space to give an interpretation in real space are central to small angle scattering, and will be discussed in detail. Several examples will be given of the successful use of small angle neutron and X-ray scattering applied to problems where other techniques have failed to make a decisive contribution. 38812
Heidt, H.; Stade, J.
State and prospects of industrial neutron radiography in Germany (In
German) Materialprnfung, Vol. 30, No. 5, pp. 137-139 (May 1988) Although the first neutron radiographies in Germany were made nearly 50 years ago, this nondestructive testing method has not yet been widely used in industry. The main reason is the lack of mobile, intensive and low-cost neutron sources. Another important aspect is the availability of real-time inspection systems equipped with neutron image amplifiers which will accelerate the test and permit to represent dynamic processes. New applications for mobile neutron sources may be expected in aircraft inspection, in testing fibre-reinforced plastics, in different types of ceramic materials, in the building sector, in corrosion protection as well as with various problems encountered with lubrication agents.
38807 Pekarskii, G.Sh. Neutron backscattering nondestructive-test instruments Soviet Journal of Nondestructive Testing, Vol. 23, No. 7, pp. 512-515 (Mar. 1988) Calculations and measurements are used to make recommendations for neutron nondestructive testing and radioisotope automatic devices operating with one-sided access. Emphasis is placed on optimizing the major components for particular industrial purposes. Operating characteristics are given for various instruments: thickness gauges, level gauges, and means of detecting blocking points in pipe-lines, etc. 38625
McCauley, J. W.
NDT: Clearing the reliability bottleneck Ceramic Industry, Vol. 130, No. 3, pp. 33-34 (Mar. 1988) Nondestructive testing will play an important role in both the production of ceramic parts and flaw detection to improve their present low reliability, as they are more widely used in industry. A wide variety of nondestructive testing techniques, appropriate to different ceramic problems are listed, with ultrasonic, radiography, optical methods and neutron scattering being of most benefit for both green- state and sintered ceramics. 38526
Panakkal, J.P.; Ghosh, J.K.
A simple model for neutron radiography of uranium-plutonium mixed oxide fuel pins Journal of Nuclear Materials, Vol. 153, No. 1-3, pp. 82-85 (Apr. 1988) Neutron radiography has been used for monitoring plutonium enrichment in uranium-plutonium mixed oxide fuel pellets, inside welded nuclear fuel pins, by correlating the optical density of radiographs at the centre of the pellets and plutonium enrichment. Optical density data corresponding to different thicknesses of the pellets starting from the centre towards the periphery was generated by microdensitometer scanning of neutron radiographs of the experimental fuel pins. An attempt has been made to correlate the optical density at points corresponding to different thickness segments of the pellets and thermal neutron interaction probability (product of the total macroscopic neutron cross section and the distance traversed by the neutrons). Based on the experimental data generated, a simple model for transmission of neutrons through nuclear fuel pins has been evolved. Using this model, it is possible to predict the optical density of plutonium bearing fuel pins containing pellets of different composition or diameter in neutron radiographic investigations. 38517
Ratcliffe, B.J.
Investigation into the use of track-etch imaging to produce neutron radiographs from a non-reactor neutron source British Journal of Nondestructive Testing, Vol. 30, No. 3, pp. 183-188 (May 1988) A study is described of the use of cellulose nitrate with an enriched boron-10 converter screen for producing neutron radiographs from a RARDE non-reactor neutron assembly. Investigation into the required exposure and etching times has been made together with the measurement of unsharpnesses. The study shows that track-etching gives a sharper image than that obtained with
NDT International August 1989
the dysprosium transfer technique and the image is available for viewing in a much shorter time.
Lambrineas, P.; Finlayson, T.R.; Griffiths, J.R.; Howard, C.J.; Smith, T.F.
38220
Neutron diffraction residual stress measurements on a thin steel plate N D T International, Vol. 20, No. 5, pp. 285-290 (Oct. 1987) Residual stress measurements are made on a thermally stressed steel plate (4 mm thick) by using neutron diffraction. The sin/sup 2/psi technique, commonly employed to measure residual stresses by using X- ray diffraction, is applied to show that the stresses are biaxial, lying within the plane of the plate, and to evaluate the magnitude of the stresses. Measurements are made in both transmission and reflection geometries. Stress measurements made in a particular sample orientation are reproducible to within + - 10 MPa. The principal stresses determined from a series of such measurements have an uncertainty of + - 30 MPa, which is comparable to the + - 20 MPa commonly quoted for the X-ray sin/sup 2/psi technique. 38217 Brenizer, J.S.; Tobin, K.W.; Hylko, J.M.; McRae, D.D.; Jenkins, R.W. Jr. Quantitative measurement of equivalent water density in a burning
cigarette Materials Evaluation, Vol. 45, No. 11, pp. 1310-1314 (Nov. 1987) As a result of an ongoing attempt to quantify the deposition of hydrogenous compounds along the axial direction of a burning cigarette, software has been developed that takes into account the statistical nature of the neutron imaging system. This allows small variations in pixel luminance to be recorded in real time during the burn and correlated to an equivalent water density. The data collection process is based on spatial grouping of pixel locations within the rod as well as a time-averaged input of these discrete pixel groups. Once the system has been calibrated, a cigarette is positioned in the neutron beam. The area of interest is then divided into ten equal parts. All the pixel luminances in an area are averaged into one representative luminance value. As the cigarette burns, these areas are simultaneously sampled. A statistical analysis is performed for the real-time averages, and the data are stored in a file for later analysis. 38212
Ratcliffe, B.J.
Development of a non-reactor neutron radiographic assembly using a 12 MeV linear electron accelerator British Journal of Nondestructive Testing, Vol. 30, No. 2, pp. 94-98 (Mar. 1988) A description is given of the development of a neutron radiography assembly which does not use a nuclear reactor. The neutron radiographic technique developed can in some circumstances detect explosive in metal ordnance with a greater sensitivity than X- radiography. 38211
Mayers, J.; Baciocco, G.; Hannon, A.C.
Temperature measurement by neutron resonance radiography Rutherford Appleton Laboratory, Didcot (United Kingdom), RAL-88-017, 14 pp. (Mar. 1988) We present a new data analysis technique for obtaining temperatures from neutron resonance radiography measurements. The technique is applied to measurements on tantalum and rhenium foils, a high temperature engineering alloy and a model catalytic system. Temperatures have been obtained to an accuracy of better than + - 1 C in the temperature range 21 C to 600 C. The results, are in good agreement with theoretical simulations. 38210
Orphan, V.J.; Maung, T.
Robotic aircraft scanner for neutron radiographic inspection Proceedings of the 35th Conference on Remote Systems Technology, Los Angles, California (United States), Nov. 1987. pp. 195-199 American Nuclear Society, 1988. A robotic positioner and manipulator, a key component of a Mobile Neutron Radiography System (MNR) for aircraft inspection, is described. The MNRS is designed to inspect military aircraft for hidden corrosion in aluminum structures. MNRS is comprised of an accelerator-based (Kaman A-711 sealed-tube neutron generator using the D-T reaction) thermal neutron source, electronic neutron imaging system, robotic positioner and manipulator for the source/imager, control trailer housing system control electronics and digital image processing system, mobile dark room for film processing, a self-contained electrical power source and a radiation safety system. For in situ aircraft inspection, the Robotic Scanner is programmed (in a teach-learn mode) to scan a region of the components (e.g., wings, stabilizers, etc.) using a control pendant. 38209 Beynon, T.D.; Constantine, G. Deep penetration radiography using 24.5 keY neutrons Nuclear Instruments and Methods in Physics Research, Vol. A264, No.2/3, pp. 526-527 (15 Feb. 1988) A series of experiments is described which demonstrates how neutrons from the natural iron filter on the Harwell PLUTO reactor can radiograph objects through 152 mm of mild steel. 38202 Catchen, G.L.; Hughes, D.E.; Kulkarni, A.K.; Ross, K.M.; Ammerman, W.R.
Development of a neutron-radiographic technique for investigating physical models of fluidized beds Chemical Engineering Communications, Vol. 54, No. 1-6, pp. 73-84 (1987)
243
This paper describes the results of the application of neutron radiography to the study of a two-phase medium, and the resulting technique can be extended to the study of two-phase flow in a fluidized bed. Neutron radiography allows the nonintrusive visualizationof a sand/air bed enclosed in aluminum walls. This capability exceeds findings using conventional optical or radiographic techniques. A static 15 cm thick sand model was constructed and examined by the radiographic technique. The technique employed a collimated thermal column of neutrons, an image intensifier, and conventional photography. To simulate a fluidized bed, spherical voids of several centimeters in diameter were created by placing thin-walled empty aluminum shells in the sand bed. Also, hollow tubes were inserted in the bed. As a function of neutron flux, high contrast images of the voids inside the 15 cm thick bed were obtained and analyzed. This technique can be extended to the study of dynamic beds by using the neutron source, i.e. the nuclear reactor, in the pulsed mode.
Shuford, R.J.; Murray, T.J. Jr.; Bostic, M.T.; Brockelman, R.H.; Hinton, Y.L. 38016
Evaluation of nondestructive evaluation techniques for detecting moisture in composite materials l l t h World Conference on Nondestructive Testing, Las Vegas, Nevada (Un ited States), 3-8 Nov. 1985. Vol. 2, pp. 1366-1373. Taylor Publishing Co., Dallas (1985). Fiber reinforced organic matrix composites are being used or proposed as primary and secondary structures for numerous military and commercial applications. The structural behavior of these advanced materials are known to be affected by in-service environmental conditions (humidity, temperature, etc.). Absorbed moisture causes the matrix to swell, lowers the glass transition temperature of the resin (plasticization), induces residual stresses and microcracking in the composite, and can irreversibly degrade the fiber/matrix interface. In addition, moisture in prepregs (caused by improper storage) can change the curing behavior and degrade the physical and mechanical properties of the fabricated composite. This paper describes an on-going investigation to develop and evaluate practical NDE techniques for monitoring moisture in fiber reinforced epoxy resin prepregs and composites. NDE techniques being studied include: pulsed NMR, infrared thermography, ultrasonics, DC resistance, microdielectrometry, neutron radiography and acoustic emission. 37896
Maier, P.; Pfister, G.; Stier, G.; Kegreiss, W.; Hehn, G.
Progress in neutron tomography for non-destructive testing Neutr on Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 771-782. D. Reidel Publishing Company A neutron computer tomography scanner was developed and constructed using portable equipment and different neutron sources. Further studies will be done with cf-252 neutrons and fission neutrons from a nuclear reactor. Since each neutron source contains gamma radiation as well simultaneous neutron and a gamma $computer tomograph (CT) images are possiblel. In non-destructive material testing, fast neutrons can be used to examine thick metallic samples or to show small differences in the concentration of light nuclei. Several image reconstruction algorithms are available for samples with different size and material composition. A spatial resolution of 0.5 mm and a density resolution of about 5% could be achieved with the first CT images with fast neutrons. Neutron CT images show few artifacts compared to x-ray scans. Therefore the neutron CT technique can be used with advantage to examine strongly inhomogenous samples. Up to now the single beam technique has been used for all measurements. The Fanbeam technique is under study to reduce the measuring time. 37895
Froom, D.A.; Barton, J.P.
Plans for aircraft maintenance neutron radiography systems Neutron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 431-438. D. Reidel Publishing Company This paper outlines the key steps taken in the acquisition process, including design and specifications, for two neutron radiography systems for the inspection of removed aircraft components. 37894 Fufine, S.; Yoneda, K.; Kanda, K. Digital image processing for real-time neutron radiography Neutr on Radiography, Proceedings of ~the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. ~537-546. D. Reidel Publishing Company The real-time neutron radiography system of Kyoto University Research Reactor Institute (KURRI) has been used to identify the Location of burnable poison in the side plates of MTR type reactor fuel and to investigate moving objects, and also for neutron computed tomography. This paper describes several image processing techniques such as image integration, adaptive smoothing and image enhancement for real-time neutron radiography. 37893
Cocking, S.J.; Harris, D.H.C.
Robust equipment for dynamic neutron fluoroscopy Neutr on Radiograp hy, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 527-536. D. Reidel Publishing Company Compact and reliable equipment for dynamic neutron fluoroscopy has been developed and used in inspection tasks. The equipment is based on a zinc sulphide-lithiumfluoride composite neutron fluorescent screen and is viewed by a silicon intensifier target television camera. The real time image can be recorded with a standard video recorder and definition enhanced using a digital
244
image processor. Using a cold neutron beam at the D100 reactor, well contrasted image features of 1 mm dimension moving at 3 cm/sec can be readily observed. 37892
McClellan, G.C.; Tow, D.M.
Neutron tomography of damaged reactor fuel assemblies Neutron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 711-718. D. R e i de l Publishing Company A neutron tomography capability has been developed at Argonne National Laboratory Hot Fuel Examination facility for use in the NDE of reactor fuel assemblies, including those deliberately damaged to simulate accident conditions. Following in-reactor testing, the damaged fuel assemblies are transferred to the HFEF Neutron Radiography (NRAD) Facility, which was designed and equipped to perform high quality thermal and epithermal neutron radiography of a wide variety of irradiated materials. Indium-resonance radiographs are made of the damaged fuel assembly at many angles and over the full length of the fuel region. The resulting radiographs are then digitised, and the data are transmitted to EG and G Idaho computer laboratory for reconstruction into cross-sectional views of the fuel assembly. 37891
Ma Zhenze.
A neutron radiographic facility on a research reactor and some results obtained in NDT Neutron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 79-86. D. Reidel Publishing Company The characteristics of a neutron radiographic reactor facility are briefly described. Some performance indicators of the system such as resolution and sensitivity have been experimentally tested. Some practical applications of the facility and results obtained in the quality assurance and control of several industrial products are illustrated.
Mo Da-Wei; Liu Yi-Si; Guo Zhi-Ping; An Fu-Liu; Zhang Ghao-Zong; Miao Qi- Tian.
37890
Neutron radiography study in Tsinghua University N e ut ron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 87-94. D. R e i de l Publishing Company Neutron radiography research described in this paper was performed at the research reactor of Tsinghua University, which is a pool-type light water reactor with a power of 2 MW. Work carried out included the development of neutron radiographic convertors, neutron radiography of corn roots growing in soil and an investigation of water permeation in concrete. A preliminary real-time neutron radiography system which can be used to observe two-phase flow was installed. 37889
Zhou Yongmao; Wu Fuxing; Gu Deming.
The miniature neutron source reactor (MNSR) a private nuclear tool Neutron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 95-102. D. Reidel Publishing C ompa ny This paper describes the development and applications of a prototype Minature Neutron Source Reactor (MNSR). A new commercial MNSR has been designed based on the experience gained with the prototype. The new reactor offers improved performance and an extension of the neutron radiographic facility.
Kobayashi, H.; Harasawa, S.; Tomura, K.; Takami, Y.; Shiraishi, F.; Hattori, M.; Nagahara, T.; Matsuura, T.; Ogawa, 1.," Yamamoto, Y. 37888
Neutron radiography at Rikkyo Triga-ll Reactor Neutron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 129-136. D. Reidel Publishing Company A vertical diverging collimator has been installed in the reactor tank of Rikkyo 100 kW TRIGA-II reactor. The configuration of the collimator and the beam characteristics are summarized. The sensitivityand beam purity indicators have shown that the collimator can be considered as category I. Inherent lack of sharpness for the combination of the 25 micron Gd screen and the KODAK-SR film is determined experimentally and found to be 48.0 + - 0.5 microns. One application is the inspection of mold cavities in carburetors. 37887
Matsurnoto, T.; Aizawa, 0.; Watanabe, S.
Development of a neutron radiography system at the Musashi Institute of Technology Research Reactor Neutron Radiography, Proceedings of the Second World Conference, Paris (France), 16-20 Jun. 1986. pp. 137-144. D. Reidel Publishing Company A neutron radiography (NRG) facility has been designed and installed at one of the horizontal beam ports attached to the Musashi Institute of Technology Research Reactor. An X-ray radiographic apparatus using a portable generator was also equipped for comparison with the NRG. Various combinations of convertors and X-ray films were evaluated in order to obtain a high-quality radiography. A real-time NRG has also been installed for the investigation of moving objects and for the study of neutron computed tomography (NCT). A high-quality radiographic image was obtained by an image orthicon camera and a digital processing system.
NDT International August 1989