Reference

Fast neutron radiography

Fast neutron radiography. Jager, Ernst H.; Thomanek, Franz R. (Studiengruppe Ballistik, Messerschmitt Bolkow Blohm G.m.b.H., Schrobenhausen, Ger.). Proc. Soc. Photo-Opt. Instrum. Eng., 97(Proc. Int. Congr. High-Speed Photogr., 12th, 1976), 150-2 (English) 1977. CODEN: SPIECJ. DOCUMENT TYPE: Journal CA Section: 74 (Radiation Chemistry, Photochemistry, and Photographic Processes) Section cross-reference(s): 71, 8 A sandwich arrangement of In and calcium tungstate [7790-75-2] on both sides of an x-ray film, all inside a std. medical aluminum film cassette, was used in making shadowgraphs with fast n. When exposed to a n flux, the In plates store a latent shadowgraph of an object, placed between the n source and the sandwich, through an (n,.gamma.)-reaction in the In. The information conveyed by a fast n shadowgraph is partially complementary to that of an x-ray picture because fast n are absorbed about equally in both light and heavy elements, whereas x-rays are absorbed preferably by the heavy elements. With a sufficiently strong n flash source, this technique should be applicable in recording fast events. About 1012 n/m2 should produce a useable image. However, this is a very severe requirement for a flash source of fast n.

Sensitivity of intensifying screens to scattered radiation in radiography: physical measurements

Sensitivity of intensifying screens to scattered radiation in radiography: physical measurements. Castle, J. W. (Res. Lab., Eastman Kodak Co., Rochester, N. Y., USA). J. Electrochem. Soc., 124(6), 901-3 (English) 1977. CODEN: JESOAN. DOCUMENT TYPE: Journal CA Section: 71 (Nuclear Technology) Section cross-reference(s): 8 The x-ray absorption of rare earth (Gd-La as oxysulfides) and medium speed CaWO4 [7790-75-2] screens was measured in regions of high and low radiog. d. of a chest phantom. The ratio of absorptions for the 2 regions was higher for the rare earth screens. This confirms by direct measurement that the higher obsd. radiog. contrast for the rare earth screens when compared to CaWO4 screens is caused by the change in absorption of the screen phosphors with change in transmitted beam quality. The net effect in rare earth screens of this type is a redn. in the recording of scattered radiation with an increase in the percentage of information-contg. (primary) radiation. The degree of this effect is a function of the amt. of scattered radiation in the transmitted beam incident on the cassette.