Accession Number : ADA296596

Title :   OPERATION GREEHOUSE: Scientific Director's Report of Atomic Weapon Tests at Eniwetok, 1951. Annex 1.9. Air-Drop Instrumentation. Part 3. Disc Camera.

Corporate Author : EDGERTON GERMESHAUSEN AND GRIER INC BOSTON MA

PDF Url : ADA296596

Report Date : AUG 1951

Pagination or Media Count : 40

Abstract : The disc camera was designed for use in aircraft to determine the growth characteristic of the fireball and so the yield. The instrument has three separate optical systems and can record three separate streak images of the fireball on a rotating glass photographic plate. Each streak image shows the growth of the fireball along a diameter with respect to time; the three traces are displaced radially to avoid confusion. The shutters are opened at approximately -3 sec, and a phototube pulser circuit is arranged to close them before one revolution of the disc after zero time. The angular velocity of the photoplate at the time of exposure is determined by marker pips recorded on the photoplate. The marker generator is gated by a phototube and is turned off by a time delay. Time to minimum can be determined directly from the streaks, and by the use of the scaling laws, Bhangmeter yield can also be determined. For Operation Greenhouse two cameras were operated in phototowers. Good records were obtained on the first two shots. On George shot, which was a daylight test, the photocell in the fiducial marker did not function and no records were obtained. The cameras were not operated on Item shot. The yields derived compare favorably with those from the other fireball determinations and with radiochemistry.

Descriptors :   *INSTRUMENTATION, *PHOTOGRAPHIC ANALYSIS, *NUCLEAR FIREBALL, *STREAK CAMERAS, VELOCITY, YIELD(NUCLEAR EXPLOSIONS), TIME INTERVALS, AIRCRAFT, PULSE GENERATORS, GLASS, SCALING FACTOR, DELAY, AIR DROP OPERATIONS, MARKERS, DISKS, ROTATION, ELECTRIC GENERATORS, CIRCUIT ANALYSIS, PHOTOGRAPHIC PLATES, DAYLIGHT, RADIOCHEMISTRY, PHOTOTUBES.

Subject Categories : Nuclear Weapons
      Photography

Distribution Statement : APPROVED FOR PUBLIC RELEASE