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Explosive Argon Flashlamp
By G. H. WINNING and H. E. EDGERTON
Oscillo graphic measurements of the light output from argon explosive flashlamps show that the flash duration is about 1 jusec for a 0.5-cm thickness of argon over the end of a cone of cast pentolite 2 in. in diameter. The peak light output is about 200 million cp, and the total output about 200 cp sees. Photographs of the argon lamps were made with a magnetooptic shutter having an effective exposure of about 1 pisec to show the space origin of the light.
HE PHOTOGRAPHY of detonations by means of an ordinary single-exposure camera has been difficult to accomplish for two reasons. First, either the light from the detonation of high-temperature explosives is so actinic as to fog the film; or the light from the detonation of relatively low-temperature explosives such as those of the permissible, coal-mining type, for example, is insufficient to affect the film in the brief exposure time required to stop the motion. Second, although conventional short-flash electronic flashlamps might be considered for some purposes, their use is expensive because the lamp is destroyed by the explosion.
The second difficulty may be overcome, for problems where the subject is not excessively large, by the use of
Presented on April 23, 1952, at the Society's Convention, at Chicago, 111., by C. H. Winning, E. I. duPont de Nemours & Company, Explosives Dept., Eastern Laboratory, Gibbstown, N.J., and H. E. Edgerton, Massachusetts Institute of Technology, Electrical Dept., Cambridge 39, Mass.
another explosive to produce light at the proper time. A relatively inexpensive, expendable, flash-producing, explosiveactivated lamp is described here. The objects of this paper are, first, to present oscillographic measurements of the light output from an argon-filled explosive flashlamp and, second, to present sequence photographs of the exploding lamp itself for correlation with the oscillograms.
Successful photography of self-luminous subjects may be accomplished by the use of Kerr cells, Faraday-effect shutters, and by image-converter tubes. The series of photographs published here of the explosive argon flashlamp during explosion were taken with the Rapatronic shutter (Faraday magnetooptic type).
Argon Flashlamp
In 1937 Michel-Levy and Muraour published a series of pictures which illustrated that rapidly occurring events, such as the deformation of a lead block by an explosive, could be photographed at desired instants during the process through proper use of the short, intense
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September 1952 Journal of the SMPTE Vol. 59