Practical Neutron Radiography, 1992

TIlls book is the result of an effort made by several members of the Euratom Neutron Radiography Working Group (NRWG) to produce a new, revised and enlarged edition of the Neutron Radiography Handbooldlj (NRH), written by members of the NRWG and published in 1981, just before the First World Conference on Neutron Radiography (WCNR) (1981). Members of the NRWG have contributed with many papers both to the first (1981)[2), as well as the second (1986)[3) and third (1989) [4) World Conference on Neutron Radiography (WCNR). They were also among the editors of the proceedings of those conferences (1982, 1987, 1990). The NRWG was constituted mainly for the purpose of promoting neutron radiography (NR) in the field of nuclear reactor fuel. Therefore the next topical publication of the NRWG were Reference Neutron Radiographs of Nuclear Reactor Fuel (1984)[5). The book on Collimators for y Thermal Neutron Radiograph 6/ written in 1987 by a member of the NRWG was another publication in the same series of books on NR. To the same series belongs the present book on Practical Neutron Radiography (PNR). It will be followed soon by another book written by the members of the NRWG: Neutron Radiography on Nitrocellulose Filmf71. The NRWG concentrated its interest in the past years on the problem of dimensional measurements from neutron radiographs. The results of the investigation of this problem were summarized in a special EUR report about the Neutron Radiography Working Group Test Program[8/ published in 1989.

1. Introduction.- 2. Historical Development.- 3. Mathematical and Physical Foundations.- 4. Neutron Sources.- 4.1 Thermal Neutron Reactors.- 4.2 Accelerators.- 4.3 Radioisotopes.- 4.4 Sub-Critical Assemblies.- 4.5 Comparison of Neutron Sources.- 5. Neutron Beam.- 5.1 Nuclear Cross-Sections.- 5.2 Calculation of The Cross-Sections of Compounds.- 5.3 Neutron Moderation.- 5.4 Attenuation Coefficients.- 5.5 Utilization of The Attenuation of Radiation in Radiography.- 6. Imaging Techniques.- 6.1 Direct Exposure Technique.- 6.2 Transfer Technique.- 6.3 Track-Etch Technique Using Nitrocellulose Film.- 6.4 Dynamic Imaging Methods.- 6.5 Tomography.- 6.6 Comparison of Various Imaging Techniques.- 7. Image Recorders.- 7.1 Photographic Film.- 7.2 Nitrocellulose Film.- 7.3 Comparison Between Silver-Halide and Nitrocellulose Film With Regard to Image Recording and Quality.- 8. Converters.- 8.1 Converters for Direct and Transfer Technique.- 8.2 Converters for Photographic Film Imaging.- 8.3 Converters for Track-Etch Method.- 9. Neutron Radiography Facilities.- 9.1 Choice of Neutron Sources.- 9.2 Neutron Beam Filters.- 10. Collimators.- 10.1 Collimator Geometry.- 10.2 Other Collimation Considerations.- 10.3 Collimator Design.- 10.4 Walls and Their Lining.- 10.5 Filling of The Collimator.- 10.6 Shutters and Diaphragms.- 10.7 Seals for in-Pool Collimators.- 10.8 Measuring of The L/D Ratio.- 11. Radiographic Techniques.- 11.1 Geometry of Exposure.- 11.2 Exposure Factors.- 12. Exposure Facilities.- 12.1 Mounting of Objects for Radiography.- 12.2 Geometry of Exposure.- 12.3 Shielding.- 12.4 Radiation Safety.- 12.5 Marking and Identification.- 12.6 Image Quality Indicators.- 12.7 Exposure Chart/Technique Log.- 12.8 Examples of an Exposure Facility.- 13. Processing of Films.- 13.1 Silver Halide Film.- 13.2 Nitrocellulose Film.- 14. Radiographic Darkroom and Accessories.- 14.1 Darkroom Lay-Out.- 14.2 Cassettes.- 15. Viewing of Neutron Radiographs.- 15.1 Viewing Conditions.- 15.2 Neutron Radiographs on Silver Halide Film.- 15.3 Neutron Radiographs on Nitrocellulose Film.- 15.4 Assessment, Interpretation and use of Radiographs on Nitrocellulose Film.- 16. Measuring Dimensions From Neutron Radiographs.- 16.1 Measuring Methods and Instruments.- 16.2 Phase Analysis Technique.- 16.3 The Nrwg Test Program.- 16.4 Dimensions Measured From Neutron Radiographs.- 16.5 Accuracy of Dimensional Measurements.- 16.6 Conclusions About Measuring Accuracies.- 17. Indicators for Image Quality Control.- 17.1 IQI’s Used in Industrial Radiography.- 17.2 The Astm Beam Purity Indicator.- 17.3 The Nrwg Beam Purity Indicator.- 17.4 Use of The BPI’s.- 17.5 The Nrwg Beam Purity Indicator-Fuel.- 17.6 Determination of Exposure Contributors.- 17.7 Sensitivity Indicator.- 17.8 Neutron Radiographic Categories.- 17.9 The Afnor IQI’s.- 17.10 Calibration Fuel Pin.- 17.11 Evaluation of The Astm And Nrwg Indicators.- 17.12 Evaluation of The Afnor Indicators.- 17.13 Other Methods.- 18. Typical Applications of Neutron Radiography.- 18.1 General Survey.- 18.2 Nuclear Applications.- 18.3 Technical and Industrial Applications.- 18.4 Non-Industrial Applications.- 19. Dynamic Neutron Radiography.- 19.1 Neutron Beam Characteristics.- 19.2 Imaging Systems.- 19.3 Applications.- 20 Standards in The Field of Neutron Radiography.- 20.1 Present Status.- 20.2 National Standards.- 20.3 International Standards.- 21. Neutron Radiography Facilities in The European Communities.- 21.1 NR Facilities for Different Applications.- 22 Terminology and Definitions.- 23 Useful Data.- Acknowledgements.- References.