Page:Operation Crossroads 1946.pdf/83

 :(33 km) from the detonation and on an aircraft flying 18 nmi (33 km) from the detonation. For BAKER, instruments were installed on a ship positioned 10.9 nmi (20 km) from the detonation and spectroscopes were placed on an aircraft flying 7.2 nmi (13 km) from the burst.


 * Staffing: BuOrd Instrumentation Group personnel manned the projects in this program with some help from AAF. Potential for exposure of Program VI personnel was quite low. Aircraft and ships involved remained clear of radioactive areas in and downwind of the Bikini Lagoon. BuOrd Instrumentation Group personnel had low exposures as can be seen from Table 6. Most personnel working in Program VI were not badged and those that were had readings less than 1.0 R.


 * Project Report: Reference C.9.209, Enclosure H.

Program VII -- Radiation Measurements


 * Agency: Los Alamos Laboratory


 * Operations: The first of the three projects in this program was the measurement of fast neutrons on ABLE test by placing sulfur samples on several target ships.


 * The second was measurement of gamma-ray emissions from BAKER detonation. During this project, gamma-ray measurement signals were transmitted from the bomb case to USS Cumberland Sound (AV-17) just before the transmitters were destroyed.


 * The third project was collection and measurement of air and water samples to determine the efficiency of the detonations. This included the use of drone aircraft (B-17 and F6F) and drone boats to obtain radioactive air and water samples.


 * The Army B-17 drones were guided from Enewetak to Bikini by a B-17 controller aircraft. On ABLE they samples at 12,000, 18,000, 24,000, and 30,000 feet (3.66, 5.49, 7.32, and 9.14 km) between 6 and 15 minutes after the detonation. On BAKER they sampled at 6,000 and 10,000 feet (1.83 and 3.05 km) between 5 and 10 minutes after the detonation. Each B-17 drone aircraft had a filter box mounted in place of its top turret and a large inflatable rubber bag in its bomb bay. The air filter unit with its special filter paper was designed to filter 90 cubic feet (7.5 cubic meters) of air in 30 seconds. The rubber bag was opened on command of the controller in the B-17 control aircraft when the drone entered the cloud. It automatically closed 30 seconds later, capturing 90 cubic feet (7.5 cubic meters) of air. The drones were guided back to Enewetak where they were landed by ground controllers. Los Alamos Report No. 613 (Reference C.1.1) describes removal of the filter unit:


 * The AAF filter unit was fixed to the top turret of a drone B-17. A lanyard ran from the unit down along the outside fuselage and ended in a handle fixed near the door of the plane. One sharp pull on the lanyard brought the filter unit tumbling down. Each door of the unit itself was fitted with a short lanyard. One sharp pull of this lanyard, and the door leaped

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