orre The objective of Project 2.6 was to provide data on neutron flux (primarily 14 Mev neutrons) versus range from a megaton weapon detonated at a very high altitude. “The instrumentation, in three pods for each shot, was carried aloft by the Redstone missile and ejected ballistically at predeter- mined ranges. The neutron spectrum was measured by the time-of-flight method with special_attention being given to the 14.2 Mev neutron group. Various types of detectors measured fast and slow fission-neutrtns, background and prompt gamma rays, gamma ray dose, and interference effects, such as electromagnetic disturbances. The detector outputs were electronically encoded, commutated, and recorded on a magnetic tape recorder. The latter was programmed to record for 120 msec after the prompt gamma ray pulse and to switch repeatedly to a playback condition to telemeter the recorded information to a telemetry station in the missile control bunker. The objectives of this project were apparently accomplished. Gamma ray measurements were consistent from pod to pod. The observed fluxes were within less than one order of magnitude of expected values. The extraction of further data (including all that on the 14.2 Mev neutrons) required oscilloscope camera methods and film processing facilities not available in the fleld. Program B: Ground Studies of Thermal and Electromagnetic Phenomena The work of Program B during shots Teak and Orange involved six projects. Project 4.1, supported by thermal measurements from Project 8.1, studied the limiting distances at which chorioretinal burns might be caused by very high altitude detonations. Rabbits were exposed to shots Teak and Orange at stations located on Johnston Island, aboard ships, and in aircraft. It was found that a very high altitude burst is particularly effective in producing chorioretinal burns because of the rapidity with which thermal 41