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The superconducting cyclotron as a transportable neutron source
neutron radiographs, reproduced on photographic paper (twice enlarged) and on duplicating film (original size). 37851
Moss, R.L.; Beers, M.
Use of epithermal neutron radiography to determine the extent of melting in mixed oxide LMFBR fuel pins i r r a d i a t e d in High Flux Reactor, Pctten N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 349-358. D. R e i d e l P u b l i s h i n g Company A series of mixed oxide fuel pins are being irradiated in the High Flux Reactor (HFR) at Petten. One of the aims of the experiments is to determine the extent of melting of the fuel under various operational conditions, including transients. By means of a cadmium filter inserted in the collimator of the reactor's neutron radiography installation, it is possible to create a source of predominately epithermal neutrons. This enables sufficient penetrations of neutrons through the fuel and produces on film distinct images of fuel melt patterns. The paper highlights some of the more revealing results within the present irradiation series. 37850
Domanus, J. C.
Euratom neutron radiography working group N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s o f the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 339-348. D. R e i d e l P u b l i s h i n g Company In 1979 a Neutron Radiography Working Group (NRWG) was constituted within Euratom with the participation of all centers within the European Community at which neutron facilities were available. The main purpose of NRWG was to standardize methods and procedures used in neutron radiography of nuclear reactor fuel as well as establish standards for radiographic image quality of neutron radiographs. The NRWG meets once a year in each of the neutron radiography centers to review the progress made and draw plans for the future. Ad-hoc sub- groups on different topics within the field of neutron radiography are constituted. This paper reviews the actix;ities and achievements of the NRWG and its sub-groups. 37849
Aderhold, H.C.; Hover, K.C.," Najjar, W.S.
The Cornell neutron radiography facility and its applications to the study of the internal structure and microcracking of concrete N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 321-328. D. R e i d e l P u b l i s h i n g Company The horizontal thermal column of the Cornell University TRIGA Mark II reactor has been adapted for neutron radiography and is described in this paper. Both a gadolinium and a gadolinium oxy-sulfide screen have been used to study concrete, and results are compared. Internal discontinuities e.g. microcracks (small fractures) and air voids have been successfully identified due to their partial impregnation with a gadolinium nitrate contrast agent. Gadolinium oxide has also been used as a contrast agent, but it was successful only in identifying air voids. A neutron radiography of a nitrate impregnated specimen is compared with x-radiographs of the same specimen with and without impregnation. Neutron radiography seems much more effective in identifying microcracks than either x-radiograph. Practical applications are suggested.
Ikeda, Y.; Ohkubo, K.; Suzuki, H.; Tomatsu, Y.; Matsumoto, G.
37848
An evaluation of neutron radiography for non-destructive testing of defects N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 305-312. D. R e i d e l P u b l i s h i n g Company Neutron radiography (NR) for non-destructive testing (NDT) of defects in structural materials was studied. Sensitivities and resolutions for various combinations of converters and emulsion films were measured and evaluated. Some defect indicators were prepared and imaged with NR to obtain practically usable data for NDT for steels and plastics. Very fine fatigued cracks in steels were detected by using a simple image- enhancement technique. In order to obtain clearer images from blurred ones, a computer reconstruction technique was developed.
37847 Attwood, P.A.; Swift, P. Cold neutron radiography of mechanical connectors N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s o f the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 281-294. D. R e i d e l P u b l i s h i n g Company The cold neutron radiography facility at Harwell has been used to investigate possible causes of serious corrosion and mechanical damage to a number of mechanical connectors installed on Shell Expro North Sea platforms. To date, neutron radiography has revealed that the elastomeric O-ring seals which are designed to prevent seawater ingress into the connector, can be displaced from their groove during assembly, resulting in severe O-ring distortion and crushing, and thereby causing ineffective sealing. Split O-rings and incomplete O-ring compression are features which have also been observed during the course of the neutron radiographic studies. Furthermore, the technique can be used to detect internal joint corrosion located within the relatively thick metal walls of the joints.
248
Tazawa, S.; Yano, M.; Nakanii, T.; Hiraoka, E.; Taniguchi, R.; Tsuji, Y.; Furuta, J. 37846
Cyclotron-based neutron radiography facility N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 231-238. D. R e i d e l P u b l i s h i n g Company Neutron radiography is not widely used yet due to a lack of high intense thermal neutron source which are convenient and economical. A new neutron radiography facility, installing a sub-compact cyclotron accelerating 18 MeV proton and equipped with both vertical and horizontal ports, is presented. Typical neutron intensity at the collimator end of L/D = 30 is 1.1 x 10/sup 6/ n/cm/sup 2//see with a field size of 14 x 17 and used mainly for real-time experiments. Prior to the construction, preliminary experiments were performed by using a proton beam from a high energy cyclotron to investigate thermal neutron intensity and neutron radiography image quality at several energy points. By optimization of neutron intensity and cost, a new facility using a 30 MeV proton cyclotron with neutron flux of 5 x 10/sup 6/n/cm/sup 2//see at field size of 14 x 17 is proposed.
Fukushima, Y.; Nakamura, T. Hiraoka, E.; Sekita, J.; Yokochi, H.; Yamada, T.; Yamaki, S.
37845
Neutron radiography using ultra-compact cyclotron N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 215-222. D. R e i d e l P u b l i s h i n g Company Neutron radiography testing was performed with an ultracompact cyclotron named BABY CYCLOTRON which produces 16 MeV protons./sup 9/Be (p,n) /sup 9/B reaction was applied for the neutron source. The collimation system has two collimators arranged horizontally, each having cross section 14 in. x 17 in., L/D ratio : 52, and thermal neutron flux of 3 x 10/sup 5/n/cm/sup 2/.s was applied at the object. Radiographic image qualities have shown very useful results and inspection of explosive devices have been carried out. 37844
Wilson, M.N.; Finlan, M.F.
The superconducting cyclotron as a transportable neutron source N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 199-206. D. R e i d e l P u b l i s h i n g Company Oxford Instruments, working in close collaboration with Amersham International, are developing a compact lightweight superconducting cyclotron. Although primarily intended for use as a local generator of short lived isotopes for PET microcomputer the same machine could also be made into a neutron generator by directing the extracted proton beam onto a beryllium target. With a proton energy of 17 MeV and a beam current of 200 micro A, the expected total neutron yield is 1.8 x 10/sup 13/neutrons/see. Using a moderator of high density polythene, this total output may be transformed into thermal neutron flux of about 1.8 x 10/sup 11/n era/sup -2/s/sup -1/. With a weight of just 200 kg, the source will be fully transportable using quite simple mechanical handling equipment. 37843
Jin Si-Kwon; Whittemore, W.L.
Neutron radiography with Van De Graaff neutron source N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 191-198. D. R e i d e l P u b l i s h i n g Company An neutron radiograph (NR) system was installed in 1983 to produce routine high quality neutron radiographs with a Van de Graaff neutron source. Two divergent beam ports emerge on opposite sides of the moderator. Two shielded walk-in cells are provided for radiography. Special features of the moderator are of interest. The moderator is especially contoured and constructed to permit at least two modes of operation: in one, a high quality NR beam is produced with a very low content of gamma rays; in the other, the NR beam contains a greatly increased fraction of very highly collimated gamma rays. For some NR objects, the compound beam compared to an essentially pure neutron beam offers particular advantages for radiographic imaging. 37842
Hawkesworth, M.R.
Reactor-quality neutron radiographs with a new mobile machine - a superconducting magnet cyclotron N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 183-190. D. R e i d e l P u b l i s h i n g Company The neutron radiographic performance of a new mobile cyclotron from Oxford Instruments Limited, which uses superconducting magnet technology, is assessed. It is concluded that thermal neutron beams comparable with those from some reactors used for neutron radiography are achievable (10/sup 5/n.cm/sup -2/s/sup-I/ at L/D = 250), and radiographs of reactor quality will therefore be available from a mobile source for the first time. There are moreover, no major technical disadvantages to militate against the cyclotron's clear neutronic advantage over other mobile sources. The machine, moderator system and immediate shielding are readily transportable as a whole, the technologies involved are all proven and reliable, and the use of the Be(p,n) reaction offers a durable target and beams with low photon contamination. 37841
Steichele, E.; Gutsmiedl, E.
A conically divergent radiography
guide tube
as a collimator
for neutron
N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e ,
NDT International August 1989
Moss, R.L.; Beers, M.
Use of epithermal neutron radiography to determine the extent of melting in mixed oxide LMFBR fuel pins i r r a d i a t e d in High Flux Reactor, Pctten N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 349-358. D. R e i d e l P u b l i s h i n g Company A series of mixed oxide fuel pins are being irradiated in the High Flux Reactor (HFR) at Petten. One of the aims of the experiments is to determine the extent of melting of the fuel under various operational conditions, including transients. By means of a cadmium filter inserted in the collimator of the reactor's neutron radiography installation, it is possible to create a source of predominately epithermal neutrons. This enables sufficient penetrations of neutrons through the fuel and produces on film distinct images of fuel melt patterns. The paper highlights some of the more revealing results within the present irradiation series. 37850
Domanus, J. C.
Euratom neutron radiography working group N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s o f the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 339-348. D. R e i d e l P u b l i s h i n g Company In 1979 a Neutron Radiography Working Group (NRWG) was constituted within Euratom with the participation of all centers within the European Community at which neutron facilities were available. The main purpose of NRWG was to standardize methods and procedures used in neutron radiography of nuclear reactor fuel as well as establish standards for radiographic image quality of neutron radiographs. The NRWG meets once a year in each of the neutron radiography centers to review the progress made and draw plans for the future. Ad-hoc sub- groups on different topics within the field of neutron radiography are constituted. This paper reviews the actix;ities and achievements of the NRWG and its sub-groups. 37849
Aderhold, H.C.; Hover, K.C.," Najjar, W.S.
The Cornell neutron radiography facility and its applications to the study of the internal structure and microcracking of concrete N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 321-328. D. R e i d e l P u b l i s h i n g Company The horizontal thermal column of the Cornell University TRIGA Mark II reactor has been adapted for neutron radiography and is described in this paper. Both a gadolinium and a gadolinium oxy-sulfide screen have been used to study concrete, and results are compared. Internal discontinuities e.g. microcracks (small fractures) and air voids have been successfully identified due to their partial impregnation with a gadolinium nitrate contrast agent. Gadolinium oxide has also been used as a contrast agent, but it was successful only in identifying air voids. A neutron radiography of a nitrate impregnated specimen is compared with x-radiographs of the same specimen with and without impregnation. Neutron radiography seems much more effective in identifying microcracks than either x-radiograph. Practical applications are suggested.
Ikeda, Y.; Ohkubo, K.; Suzuki, H.; Tomatsu, Y.; Matsumoto, G.
37848
An evaluation of neutron radiography for non-destructive testing of defects N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 305-312. D. R e i d e l P u b l i s h i n g Company Neutron radiography (NR) for non-destructive testing (NDT) of defects in structural materials was studied. Sensitivities and resolutions for various combinations of converters and emulsion films were measured and evaluated. Some defect indicators were prepared and imaged with NR to obtain practically usable data for NDT for steels and plastics. Very fine fatigued cracks in steels were detected by using a simple image- enhancement technique. In order to obtain clearer images from blurred ones, a computer reconstruction technique was developed.
37847 Attwood, P.A.; Swift, P. Cold neutron radiography of mechanical connectors N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s o f the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 281-294. D. R e i d e l P u b l i s h i n g Company The cold neutron radiography facility at Harwell has been used to investigate possible causes of serious corrosion and mechanical damage to a number of mechanical connectors installed on Shell Expro North Sea platforms. To date, neutron radiography has revealed that the elastomeric O-ring seals which are designed to prevent seawater ingress into the connector, can be displaced from their groove during assembly, resulting in severe O-ring distortion and crushing, and thereby causing ineffective sealing. Split O-rings and incomplete O-ring compression are features which have also been observed during the course of the neutron radiographic studies. Furthermore, the technique can be used to detect internal joint corrosion located within the relatively thick metal walls of the joints.
248
Tazawa, S.; Yano, M.; Nakanii, T.; Hiraoka, E.; Taniguchi, R.; Tsuji, Y.; Furuta, J. 37846
Cyclotron-based neutron radiography facility N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 231-238. D. R e i d e l P u b l i s h i n g Company Neutron radiography is not widely used yet due to a lack of high intense thermal neutron source which are convenient and economical. A new neutron radiography facility, installing a sub-compact cyclotron accelerating 18 MeV proton and equipped with both vertical and horizontal ports, is presented. Typical neutron intensity at the collimator end of L/D = 30 is 1.1 x 10/sup 6/ n/cm/sup 2//see with a field size of 14 x 17 and used mainly for real-time experiments. Prior to the construction, preliminary experiments were performed by using a proton beam from a high energy cyclotron to investigate thermal neutron intensity and neutron radiography image quality at several energy points. By optimization of neutron intensity and cost, a new facility using a 30 MeV proton cyclotron with neutron flux of 5 x 10/sup 6/n/cm/sup 2//see at field size of 14 x 17 is proposed.
Fukushima, Y.; Nakamura, T. Hiraoka, E.; Sekita, J.; Yokochi, H.; Yamada, T.; Yamaki, S.
37845
Neutron radiography using ultra-compact cyclotron N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 215-222. D. R e i d e l P u b l i s h i n g Company Neutron radiography testing was performed with an ultracompact cyclotron named BABY CYCLOTRON which produces 16 MeV protons./sup 9/Be (p,n) /sup 9/B reaction was applied for the neutron source. The collimation system has two collimators arranged horizontally, each having cross section 14 in. x 17 in., L/D ratio : 52, and thermal neutron flux of 3 x 10/sup 5/n/cm/sup 2/.s was applied at the object. Radiographic image qualities have shown very useful results and inspection of explosive devices have been carried out. 37844
Wilson, M.N.; Finlan, M.F.
The superconducting cyclotron as a transportable neutron source N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 199-206. D. R e i d e l P u b l i s h i n g Company Oxford Instruments, working in close collaboration with Amersham International, are developing a compact lightweight superconducting cyclotron. Although primarily intended for use as a local generator of short lived isotopes for PET microcomputer the same machine could also be made into a neutron generator by directing the extracted proton beam onto a beryllium target. With a proton energy of 17 MeV and a beam current of 200 micro A, the expected total neutron yield is 1.8 x 10/sup 13/neutrons/see. Using a moderator of high density polythene, this total output may be transformed into thermal neutron flux of about 1.8 x 10/sup 11/n era/sup -2/s/sup -1/. With a weight of just 200 kg, the source will be fully transportable using quite simple mechanical handling equipment. 37843
Jin Si-Kwon; Whittemore, W.L.
Neutron radiography with Van De Graaff neutron source N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 191-198. D. R e i d e l P u b l i s h i n g Company An neutron radiograph (NR) system was installed in 1983 to produce routine high quality neutron radiographs with a Van de Graaff neutron source. Two divergent beam ports emerge on opposite sides of the moderator. Two shielded walk-in cells are provided for radiography. Special features of the moderator are of interest. The moderator is especially contoured and constructed to permit at least two modes of operation: in one, a high quality NR beam is produced with a very low content of gamma rays; in the other, the NR beam contains a greatly increased fraction of very highly collimated gamma rays. For some NR objects, the compound beam compared to an essentially pure neutron beam offers particular advantages for radiographic imaging. 37842
Hawkesworth, M.R.
Reactor-quality neutron radiographs with a new mobile machine - a superconducting magnet cyclotron N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e , Paris ( F r a n c e ) , 16-20 Jun. 1986. pp. 183-190. D. R e i d e l P u b l i s h i n g Company The neutron radiographic performance of a new mobile cyclotron from Oxford Instruments Limited, which uses superconducting magnet technology, is assessed. It is concluded that thermal neutron beams comparable with those from some reactors used for neutron radiography are achievable (10/sup 5/n.cm/sup -2/s/sup-I/ at L/D = 250), and radiographs of reactor quality will therefore be available from a mobile source for the first time. There are moreover, no major technical disadvantages to militate against the cyclotron's clear neutronic advantage over other mobile sources. The machine, moderator system and immediate shielding are readily transportable as a whole, the technologies involved are all proven and reliable, and the use of the Be(p,n) reaction offers a durable target and beams with low photon contamination. 37841
Steichele, E.; Gutsmiedl, E.
A conically divergent radiography
guide tube
as a collimator
for neutron
N e u t r o n R a d i o g r a p h y , P r o c e e d i n g s of the S e c o n d W o r l d C o n f e r e n c e ,
NDT International August 1989