Table Of Content. -έζ.1
RADIOGRAPHY WITH NEUTRONS
Conference held 10-11 September, 1973
at the University of Birmingham
Technical editor
M. R. HAWKESWORTH, BSc, MSc, PhD,
Department of Physics, University of Birmingham
London, British Nuclear Energy Society, 1975
ORGANIZING COMMITTEE
R. Halmshaw, Ministry of Defence, Fort Halstead
M.R. Hawkesworth, Department of Physics, University of Birmingham
R.S. Matfield, Atomic Energy Research Establishment, Harwell
J. Walker, Department of Physics, University of Birmingham and Birmingham Radiation
Centre
Production Editor: Mary Monro, BA
ISBN 0 7277 0019 7
(c) The British Nuclear Energy Society, 1975. Published by Thomas Telford Limited,
London
The British Nuclear Energy Society as a body is not responsible for the statements
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written permission of the British Nuclear Energy Society.
Preface
In the United Kingdom neutron beams were first employed for radiographic
purposes by J. Thewlis and R. T. P. Derbyshire in the 1950s at AERE,
Harwell, Thermal neutron beams from the BEPO reactor were used, and the
main objective was to develop an additional non-destructive testing
technique for the nuclear power industry. Research into neutron radio
graphic methods in the Department of Physics, University of Birmingham,
was started by J. P. Barton and J. Walker in 1963, with the enthusiastic
support of Thewlis and the UKAEA. This programme, and that a Harwell,
continue and, whilst in Birmingham the emphasis has moved to the develop
ment of techniques for using non-reactor neutron sources, nearly all
practical neutron radiography in the UK is carried out with thermal neutron
beams from reactors, and the main user is indeed the nuclear power industry.
Thus it was entirely appropriate that Dr V. S. Crocker of Harwell and
Professor J. Walker of Birmingham should be asked by the British Nuclear
Energy Society to initiate the first UK conference on the methods and
applications of the technique, and that the University of Birmingham should
be the chosen venue.
From the outset the conference was planned to appeal to the newcomer to
neutron radiography, through the medium of review and applications papers,
and to people already familiar with the technique, by making time available
for research papers. In the event response was almost overwhelming,
emphasising current interest in the technique. Over 100 delegates attend
ed, from 12 countries, and a total of 28 papers were presented.
The organizing committee would like to record their thanks to: all con
tributors to the proceedings; the Department of Physics and the Birmingham
Radiation Centre for making their facilities available; the BNES for their
organizational and editorial help; the Institute of Physics for their
assistance with the advertising; and the Science Research Council, London,
for supporting neutron radiography research in Birmingham.
M. R. HAWKESWORTH
Conference Technical Secretary
Contents
SESSION 1: INTRODUCTION
I* Review: Radiography with neutrons. J. Walker 1
SESSION 2: RECENT DEVELOPMENTS IN NEUTRON SOURCES FOR RADIOGRAPHY
2. Review: Neutron sources for radiography. J. P. Barton 7
3. Neutron radiography facilities at the Scottish Universities Research and
Reactor Centre. J. A, Izatt 17
4. A mini-reactor for neutron radiography (MIRENE). M. Houelle, C. Mercier
and H. Revol 21
5. Neutron radiography on the research reactor HERALD. A. L. Rodgers and G. S. Tuckey 31
6. Transient neutron radiography on the VIPER pulsed reactor. M. L. Mullender and
V. J. Hart 39
7. 252Cf neutron radiographic camera. L. G. J. Bennett 45
8. Detection of failures in reactor fuel using a high output sealed tube neutron
generator. R. E. Jones 49
SESSION 3: RECENT DEVELOPMENTS IN NEUTRON IMAGE RECORDERS
9. Scintillator screens for neutron radiography. £>. Aliaga-Kelly and D. P. Nicoll 51
10. The effect of temperature on the luminescence of glass and granular neutron
scintillators. A. p. Spowart and J. P. Coats 55
11. Determination of optimum foil exposure times in neutron radiography using the
transfer method. T. Wall and P Gillespie 63
0
12. Solid state track detectors for neutron image recording. 5. A. Durrani and
H. A. Khan 71
13. Recent theoretical-experimental correlations in neutron radiographic imaging.
A. Am Harms 79
14. The application of image analysis in neutron radiography. W. E. Gardner 85
15. The automatic digitization of film images. H. P. Shaylor 89
16. Review: Neutron image recorders. M. P. Hawkesworth 95
SESSION 4: APPLICATIONS OF NEUTRON RADIOGRAPHY
17. Comparison of gamma and neutron radiography related to the ordnance industry.
P. Halmshaw and C. A. Hunt 103
18. Neutron radiography in the precision measurement of irradiated materials.
T. Robertson 107
19. Neutron radiography of irradiated fuel elements using cellulose nitrate film.
G. Farny 115
20. Two examples of quantitative neutronography. A, Laporte and J. Mars 123
21o Measurement of the amount and distribution of silicon in steel using neutron
radiography. D. Kedem and A. Ariel 129
22. Cold neutron beams for radiography through steel. Af. P. Hawkesworth and
J. Walker 133
23. Microneutronography and some applications in metallurgy. R. Ilic, J. Rant
and F. Sirca 139
24. Investigation of hydrogen motion in liquids by neutron radiography.
Mm Manoussakis, H. Rauch and Ao Zeilinger 143
25. Neutron radiography in medical research and diagnosis. D, 2C. Bewley 149
26. Industrial applications of neutronography in France. A. Laporte 151
27. Development of neutron radiography applications in the USA. J. P. Barton 157
28. A survey of applications of neutron radiography in the UK. P. 5. Matfield 165
List of delegates 169
List of delegates
Mr A. Ainsworth, Radiochemical Centre, Amersham* Mr C. A. Hunt, RARDE, Fort Halstead, Kent
Dr W. Albrecht, Forschungsinstitut fur Geochemie, Mr J. A. Izatt, SURRC, East Kilbride
W. Germany Dr H. Jagersberger, Kraftwerk-Union, Frankfurt/
Dr D. Aliaga-Kelly, Nuclear Enterprises Ltdo, Main, W Germany
0
Edinburgh Dr P. B. Jamison, Minnesota-3M Research
Dr U. W. Arndt, ILL, Grenoble, France Mr R. A. Jarjis, Dept of Physics, University of
Mr M. J, Atherton, Dept of Employment, London Aston
Dr E. Jo Axton, National Physical Laboratory, Mr R. E. Jones, Marconi-Elliott, Borehamwood
London Mr P.Jost, Bundesanstalt fllr Materialprufung.
Mr J. M. Bakes, Warren Spring Laboratories, Dr D. Kedem, Soreq Nuclear Research Centre, Israel
Stevenage Dr P. M. Kelly, Australian AEC Research Estab
Professor J. P. Barton, Radiation Centre, OSU, lishment
USA Mr P. E. Kent, AERE, Harwell
Dr L. G. I. Bennett, Royal Military College of Dr H. A. Khan, Dept of Physics, University of
Canada Birmingham
Mr U. Bergenlid, AB Atomenergi, Sweden Mr A. Laporte, CEN Fontenay, France
Dr D. K. Bewley, MRC Cyclotron Unit, London Dr T. D. MacMahon, University of London Reactor
Mr Ko A. Bradshaw, UKAEA, Windscale Centre
Mr W. G. Callister, National Vulcan Ltd, Mancheste Professor U. Malkomes, Bundesanstalt fur Material-
Mr A, C. Carter, Royal Military College, prufung
Shrivenham, Wilts Dr M. Mangialajo, CISE, Milan, Italy
Dr S. Charlton, ICI, Billingham Mr B. Mansard, CEN, Saclay, France
Mr L. Clark, DTI Inspectorate, Cumberland Mr R. S. Matfield, AERE, Harwell
Mr B. P. Clear, AERE, Harwell Mr C. Mercier, CEN, Cadarache, France
Dr M. So Coates, AERE, Harwell Mr M. L. Mullender, AWRE, Aldermaston
Miss I. R. Coats, Paisley College of Technology Mr F. Ozek, Radiation Physics, University of
Dr P. N. Cooper, University of Aston in Birmingham Surrey
Dr A. E. Cox, BNDC, Whetstone, Leics Dr R. Parker, Reed College, Portland, Oregon, USA
Dr A. J. Cox, University of Aston in Birmingham Miss P. Powell, University of Surrey, Guildford
Dr Vo S. Crocker, Maths. Phys. Div., AERE, Mr M. J. Prictoe, AERE, Harwell
Harwell Dr J. Rant, Inst Josef Sefan, Yugoslavia
Mr P. L. Davidson, Rutherford Laboratory, Berks Mr G. 0. Rees, Dunlop Ltd, Coventry
Mr K. E. Davies, Rare Earth Products Ltd, Widnes, M. H. Revol, CEA, Is-sur-Tille, France
Lanes Dr A. I. M. Ritchie, Australian AEC, Lucas
Dr P. De Regge, CEN/SCK, Belgium Heights
Mr A. T. Doel, Metropolitan Water Board Mr T. Jo Robertson, AERE, Harwell
Mr T. Downs, GEC-REL, Whetstone, Leics Dr A. L. Rodgers, AWRE, Aldermaston
Dr S. A. Durrani, Dept of Physics, University of Mr W. H. Sansom, Vickers Shipbuilding, Barrow
Birmingham Mr H. Schiilken, Gesellschaft fur Kernforschung,
Mr C, Evans, AWRE, Aldermaston Karlsruhe, W. Germany
Dr I. Evans, NCB Research, Stanhope, Bretby Mr H. Shaylor, Dept of Physics, University of
Mr G. R. Evans, Alsager, Stoke-on-Trent Birmingham
Mr G. Farny, CEN, Saclay, France Mr D. C. Shepherd, DERE, Dounreay
Mr T. B. Fox, High Voltage Ltd., Eastcote, Middx Mr A. C. Sherwood, AERE, Harwell
Dr P. E. Francois, University of Aston in Dr R. J, J. Simkins, MOD, Waltham Abbey, Essex
Birmingham Dr J.G.Slipp, Ontario Hydro - Europe
Mr E. L. Freeman, NE London Polytechnic Dr A R. Spowart, Paisley College of Technology
0
Professor J. H. Fremlin, Dept of Physics, Mr E. C. Sykes, CEGB, Berkeley Nuclear Labora
University of Birmingham tories , Glos
Dr W, E. Gardner, AERE, Harwell Mr G. S. Tuckey, AWRE, Aldermaston
Mr C. H. Gill, Marconi-Elliott, Boreharawood Mr A. G. Uglow, CEGB, Berkeley Nuclear Labora
Mr J. L. Gould, GEC-REL, Whetstone, Leics tories, Glos
Mr A. Green, Redditch, Worcs Mr P. Vanelegen, University of Brussels, Belgium
Mr J. Greenland, University of Surrey, Guildford Mr J. A. Waddams, BNFL, Risley
Mr R. Halmshaw, RARDE, Fort Halstead, Kent Professor J. Walker, Dept of Physics, University
Professor A. A. Harms, McMaster University, Canada of Birmingham
Dr M. R. Hawkesworth, Dept of Physics, University Mr J. Fo Walsh, Dept of Dental Prosthetics,
of Birmingham Manchester
Dr E. Heiberg, Atomenergi, Studsvik, Sweden Dr D. West, AERE, Harwell
Mr R. C. Herbert, Central Office of Information, Dr A. Zeilinger, Atominstitut der Osterreichishen
London Hochschulen, Austria
Dr A. Hiller, Kraftwerk-Union, W. Germany Dr R. Zilber, Soreq Nuclear Research Centre, Israel
Mr H. F. Hopkins, British Gas Corp., Solihull
M. M. Houille, CEA Is-sur-Tille, France
Mr J. Hughes, George Clark - NEM Ltd
* Locations as at date of Conference, 10
September, 1973
1. Review: Radiography with neutrons
J. WALKER, Department of Physics, University of Birmingham
This paper reviews the principles of neutron radiography and draws attention to those features
of the interactions of neutrons with matter which axe particularly relevant. The properties
required of sources and image detectors for good radiographs are discussed briefly.
INTRODUCTION 3. A compact and intense source of fast
1. It is perfectly clear that radiography with neutrons can be provided by a nuclear
beams of neutrons is now a valuable addition reaction [eg D(d, n); T(d, n); Be(d, n); Be(v, n)]
to non-destructive testing, and the aims of in the target of an accelerator or by the
this particular conference are two-fold, spontaneous fission of a small quantity of
firstly to show newcomers the capabilities 252 (5, 6),
cf
of the technique and secondly to summarise but the radiographic applications
recent developments for the benefit of of fast neutrons have not been extensive^)
established users. (For economy I have not because similar results can usually be obtained
included any radiographs in the printeH form with high-energy X-rays; at this conference
of this paper since there are many examples Bewley (paper 25) will discuss the difficulties
in the remainder of these proceedings.) in their medical uses. However, accelerators
and radioactive isotopes are important in
THE PRINCIPLES OF NEUTRON RADIO thermal neutron radiography as the suppliers
GRAPHY AND THE EQUIPMENT NEEDED of neutrons to the moderator. Figure 2
2. Figure 1 illustrates the method and shows illustrates the use of a small pumped
that the principles 2, 3) h the same accelerator in this way; the simple arrange
a re m u c
as for the long-established X- and gamma- ment shown can be improved by the use of
radiography. A source feeds the radiation conical beam tubes which view the moderator
to the sample where it is attenuated by near the target rather than the target itself.
absorption and scattering to a degree Jones (paper 8) will describe the use of a
dependent on the sample's structure and sealed-tube accelerator, a type which can be
composition; it then passes to an appropriate made rather more compact. If a source
recorder where the radiograph is produced. based on a radioactive isotope were being usedt
Up to the present, and the situation is likely it would simply be placed at the centre of the
to continue, neutrons of thermal energies moderator. Figure 3 shows the distrib
have been the most useful. As they are not utions of thermal neutron fluxes produced in
produced directly in any reaction, any source a water moderator by various sources. The
of them has to incorporate a moderator and, D-D and D-T sources are based on low-volt
as a result, it is much larger than the very age accelerators; Sb-Be and Am-Be refer
small sources which are available for X-rays respectively to the ^Be(y, n) source using
and gamma-rays. Collimation of the source gamma-rays from antimony (^^Sb) and the
radiation is thus necessary with thermal "Be(«t» n) source using a-particles from
neutrons, but fortunately this can be americium (^*Am). An idea of the capital
provided easily because of the availability of costs of different sources is given in Figure 4,
strong absorbers, such as cadmium, in a which also shows that, as a general guide, the
convenient physical form. When a nuclear sources in ascending order of flux are isotopes,
reactor is the neutron source^), the beam sealed accelerators, pumped accelerators and
hole through the shielding may provide reactors.
adequate collimation. In some applications 4, Very intense bursts of neutrons for strobo
it may be useful to have a second collimator scope applications can be produced by either
between the sample and the detector to accelerators or reactors; special examples
remove scattered neutrons. of the latter will be described by Houelle,
1
SESSION 1: PAPER 1
Neutron .
Collimator Object Film Converter
source •
\ screen
1/
Collimator
Fig.l. Typical arrangement for radiographic inspection using a beam of thermal neutrons
Fig.2. Schematic diagram of particle accelerator-moderator assembly. Typical sizes are: accelerator
length, l-2m; moderator diameter, 0.5-lm. Three probe tubes providing beams with different degrees
of collimation for radiography are shown. For maximum thermal neutron intensity the tube bases and
accelerator target should be placed as close to the centre of moderator as possible.
2
