414511 MacCuaig, N. Low cost gamma-ray tomography Proceed ings of a one -day Mee t i ng of the Mate r i a l s and Test ing G r o u p of the Ins t i tu te of Physics, 13 D e c e m b e r 1988, London . Eds. N. M a c C u a i g and R. Hol t . pp. 81-89 (1989)

In the industrial field Computed Tomography has not generally been considered as an NDE technique due to its high capital cost. The majority of commercial systems are also based on medical imaging systems which are often unsuitable for industrial problems. Isotopic source based systems can now be produced at a much lower cost and the resulting system is also optimised for the specific application to be studied.

41290 Wagh, A.S.; Pinnock, W. Radioactivity as a means of nondestructive testing Univers i ty of the West Ind ies , Kings ton ( Jamaica) , D E 8 8 7 0 2 7 7 8 / G A R , C O N F 8609282, 18 pp. (1986)

An attempt is made to develop a method in which certain solutions with radioactive solutes can be used as liquid pcnetrants. Thc gamma activity can be measured using a conventional counter~ This activity gives a measure of the quantity of the penetrated fluid and an assessment of the depth and size of the flaw can be determined. Two cases are discussed, the use of external penetrants and of inherent activity in the material. The first case is applicable in metallurgy while the second case is applicable to building material. The cxperimental arrangements will be discussed and critical comparisons with other methods will be done. The limitations of the method due to occupational health aspects will also be discussed.

41281 Sosnin, F.R. Estimation of the parameters of radiation images of defects Soviet Journa l of Nondes t ruc t i ve Tes t ing , Vol. 24, No. 4, pp. 255-258 (Dec. 1988)

Formulas and results are given from calculating the contrast and signal/noise ratio for the radiation image of a defect formed by bremsstrahlung, based on representation of its spectrum in a scale of linear attenuation coefficients of mouoenergetic radiation by a gamma distribution.

41070 Lopes, R.T.; Anjos, M.J. Determination of surface defects using Compton scattering of gamma-ray of 662 KeV Proceed ings of the 12th Wor ld Confe rence on Non-Des t ruc t ive Test ing, A m s t e r d a m (Ne the r l ands ) , 23-28 Apr . 1989, Vol. 2, pp. 1276-1278. E d i t e d by J. B o o g a a r d and G . M . van Di jk , E l sev ie r , 1989.

This system for the determination of surface defects consists of a collimated Caesium 137 source and a NaI(T1) detector. The scattering angle choscn was 90 dog. A set of aluminium blocks with different surface conditions has been tested, and imperfections up to 1.6 mm were dctcctcd.

41068 Omotosho, O.J.; Plaskowski, A.; Frith, B.; Beck, M.S. A 'non-moving part' gamma sensor for non-destructive testing Proceed ings of the 12th Wor ld Confe rence on Non-Des t ruc t ive Test ing, A m s t e r d a m (Ne the r l ands ) , 23-28 Apr . 1989, Vol. 2, pp. 11187-11192. E d i t e d by J. B o o g a a r d and G . M . van Di jk , E lsevier , 1989.

This paper presents the design of a computerized tomographic system capable of mapping dcfective spots on objects without cutting and/or rotating them. It is based on the principle of Compton-scattered gamma-photons using an external scattcrer. In particular, the choice of materials that can be used as an external scatterer; criteria of such a choice arc presented. Also, the potential advantages and the limitations of thc system arc discussed.

40965 Shim, 1. 0.; Byrne. J.G. Possible NDE correlation with fractography in 4340 steel Meta l lu rg ica l Transac t ions A , Vol. 20A, No. 2, p. 323 (Feb. 1989)

A study of fractography in 4340 steel is describcd. The steel was tempered at temperatures between 200 dog C and 700 dog C. Tcnsile fractures, which had bccn produced at room temperatures in notched specimens, were examined. Profile roughness is measured as a function of tempering temperature. Retained austenitc transformation products and non metallic inclusions were among the defects found. Positron Dopplcr measurements may offer a way to predict fracture face morphology.

40949 Shivarov, K.; Kolarova, M.; Nichev. V. Non-destructive testing of welds in quality assurance of nuclear power plants components Proceedings of the 12th Wor ld Confe rence on Non-Des t ruc t ive Test ing, A m s t e r d a m (Ne the r l ands ) , 23-28 Apr . 1989, Vol. 2, pp. 1141/-1142. E d i t e d by J. B o o g a a r d and G .M. van Di jk , E lsevier , 1989.

Non-destructive testing is performed on the welded joints in the primary circuit pipelines of I(XX) MW WWER-type nuclear reactors. Three NDT methods are applied in 14 arrangements of gamma-irradiation, ultrasound propagation, and liquid penetration aimed at detecting and determining the type, size and location of the internal and surface discontinuities.

40864 Kanamori, T.; Kamata, S.; lto, S. Density resolution estimation for gamma ray computed t o m o g r a p h y Proceedings of the 12th Wor ld Confe rence on Non-Des t ruc t ive Test ing, A m s t e r d a m (Ne the r l ands ) 23-28 Apr . 1989, Vol. 1, pp. 99-101. E d i t e d by J. B o o g a a r d and G . M . van Di jk , E lsevier , 1989

Gamma ray CT (Computed Tomography) can measure densities of high density materials such as steel and copper. This study points out that, for the density resolution estimation, it is necessary to consider the noise propagation of counts of photons passing through the object.

40863 Balasko, M.; Svab, E.; Burtscher, A. Dynamic neutron and gamma radiography at the Astra reactor in Seibersdorf Proceed ings of the 12th Wor ld Confe rence on Non-Des t ruc t i ve Test ing, A m s t e r d a m (Ne the r l ands ) 23-28 Apr . 1989, Vol. 1, pp. 96-98. E d i t e d by J. B o o g a a r d and G .M. van Di jk , E l sev ie r , 1989

Dynamic neutron and gamma radiography installation for non-destructive investigations has been built up at the 8 MW ASTRA reactor in Seibersdorf. Dynamic neutron radiography is applicable for visualizing of flow, boiling and condensation of fluids in metal tubes, whereas gamma radiography is used to visualize the inner metal parts of the investigated object. Applications include investigation of heat pipes, absorption and compression type refrigerators, espresso machines, oil pump systems, compressors, hydraulics for robot system, fuel consumption meters, and electrical valves.

40683 Allen, A.J.; Coleman, C.F.; Conchie, S.J.; Smith. F.A. Applications of positron annihilation to the monitoring of fatigue damage and creep in technological components Uni ted K ingdom A t o m i c E n e r g y Au tho r i t y , H a r w e l l , A E R E - R - 13344, 12 pp. (Nov. 1988)

This paper reviews the use of positron annihilation methods for technological applications, particularly the use of positron annihilation gamma ray lineshapc analysis for the non-destructive assessment of static deformation, machining processes, high cycle fatigue and creep in metal and alloy components. The paper includes description of a transportable lineshape analysis system recently developed for field applications.

40682 Mizunuma, M.; Hanada, H.; Takagi, I.; Kadomatsu, Y.; Kitagawa, T. Sato, K. Experiments on the detection limit of iron reinforcement rods and various types of defects in X-rays and gamma ray radiographic test of concrete. (In Japanese) Journa l of J apanese Society for Non-Des t ruc t i ve Inspec t ion , Vol. 37, No. 9A, pp. 871-872 (Sop. 1988)

411136 Hill, D.W.; Peak, J.C. Development of a one-sided gamma ray tomography system R e v i e w of Progress in Q u a n t i t a t i v e Nondes t ruc t i ve E v a l u a t i o n , Wi l l i amsburg , Vi rg in ia (Un i t ed Sta tes) , 22-26 Jun. 1987. Vol. 7A, pp. 415-424. Ed i t ed by D . D . T h o m p s o n and D . E . C h i m e n t i , P l e n u m Press, 1988.

An experimental device has been constructed which has successfully determined the location and size of macroscopic features such as voids and steel bars in concrete structures. The technique mcasures relative density variations along a planc perpendicular to thc surface of the structure using the intensity of gamma radiation scattered back from thc concrete. Collimation and energy discrimination are used to detect gamma rays from a Co-6(I source which have undergonc a single Compton scatter through a prescribed angle. The system can readily locale and discriminate between voids, cracks, and high density inclusions. Thc data is printed in a normalized format which shows the relative density at each area in the plane. The system also demonstrated the adaptability of this technique to other matrices by locating holes in a steel block. Other possible uscs include locating voids and cracks in a variety of ceramic materials and in structures containing layers of different materials.

39924 Eisen, Y.; Sivan, G.; lzak, E. An automatic system for quality control in ammunition production N D T In te rna t iona l , Vol. 21, No. 6, pp. 389-392 (Dec. 1988)

A quality-control system has been developed for all types of cartridges manufactured in the small arms ammunition industry. The Icvcl of gun powder, the regularity of the fire hole and the lead (Pb) content in several regions of the bullet arc measured. The system is fully automatic and is controlled by two microcontrollers that differentiate between good and defective cartridges. Although thc instrument is intended for off-line quality control of fully assembled cartridges, it can be modified to examine the same parameters on line.

39689 Campbell, D. Test and inspection technology keeps getting bet te r I n s t rumen t s and Cont ro l Sys tems, Vol. 61, No. 8, pp. 27-311 (Aug. 1988)

This paper reviews the latest technology in noncontact inspection techniques such as eddy currents, capacitance systems, gamma backscatter, laser applications, ultrasonic testing, X ray and optical inspection.

396311 Steinboch, L. A line-scan camera for radiography and tomography of nuclear fuel elements Proceedings of the 4th E u r o p e a n Confe rence on Non-Des t ruc t i ve Test ing, L o n d o n (Un i t ed K ingdom) , 13-17 Sop. 1987. Vol. 3, pp. 21511-2155. Pe rgamon Press, 3173 pp. (1988)

An electronic line-scan camera was developed which allows the acquisition of

1 54 NDT& E International June 1 991