A LINEAR SHAPED CHARGE NEUTRON RADIOGRAPHY PRECISE DETECTION SCHEME
Neutron radiography was researched to detect the linear density of explosive in linear shaped charge (LSC), to determine its distribution uniformity and defective. The clear images of some samples were obtained by neutron radiography, and were processed to obtain the linear density of inner explosive. The defectives such as sparseness, discontinuity and cavity were shown clearly in the images. The method, with more intuitive and more reliable results, is more direct and simpler than existing quality testing methods for LSC, and most important, the method is a non-destructive one. This new method is of significance to the precise test of LSC and its application in precise blasting; in addition, it could be used in quality test of cord type explosive device.
Detection of Corrosion in aircraft aluminum alloys
Abstract This work shows the application of an aqueous solution of gadolinium nitrate as a contrast agent in samples of AA7075 aluminum alloy used in aircraft structures for neutron radiography (NR) detection of corrosion as the pitting and exfoliation, either hidden or not, by the same alloy. Besides this, inspection for detection of simulated corrosions of several dimensions inside a cylindrical block of aluminum alloy was carried out. The neutron radiographies were taken in the NR device of the external thermal column of the Argonaut reactor, Nuclear Engineering Institute, IEN/CNEN. An image detector was used, consisting of a gadolinium converter, 50 μm thick, and a double-coated Kodak Industrex M film.
Oxygen precipitation in antimony-doped silicon
Small-angle neutron scattering is used to study the precipitation behaviour of dissolved oxygen in Czochralski-grown dislocation-free single crystals of silicon doped with antimony. The results are compared with those from undoped silicon. The precipitation of oxygen in silicon is very different for the Sb-doped material as compared with undoped silicon. Sb doping appears to slow down the rate of precipitation of oxygen in silicon into large cushion-shaped SiO2 precipitates.