3.1.3 Remarks Project 2.1 will be provided limited access to the Pad~Safe Photo Trailer for film processing. A DUK! will be required for pluce~ ment and recovery of film packs for reef and offshore stations. 4A ter will be required for recovery from contaminated lend areas, 3. 2.2 Title: Ganme Rate vs Tine rerrornine Agency Mr. Feter Brown vans Signal Laboratory 3.2.1 Objective” To provide for the measurement of gamma radiation intensity as a function of time and position along the ground for surface detona- tions of high yield. . The rate data:will be recorded over a period from 0.1 sec. to 24 hr after detonation. These data will provide a basis of evaluating the dosage contribution from the various sources of initial gamma radiation and the decay rate and dosage contribution for residual contamination fields over;the first 24 hr period. The limited gamma time intensity data obtained for the IVY deto- nations indicated a drastic di ‘ference in the time-rate of garma ex- posures for high yield deviceg*as:! compared to that for nominal weapons, primarily due to the effect ofthe blast wave on gamma radiation attenuation for high yield detonatiéds. 3.2.2 Procedur ©) n The equipment used for these meashilements consists of four scintillation counter units capable of détection of gamma ray intensities over a range of five decades. Each unit wikl be equipped with two recorders, one of about 0.1 sec. resolution eqvering the first minute period; the other of slower resolution covering-a 24 hr period. A total of 15 stations will be located on islandsof the Bikini Atoll, 10 of which will be doubly instrumented stations, chy able of recording intensities over a range of nine decades. The equipment with asso- ciated power supplies will be sealed in steel drums} and placed below ground surface except for the scintillation counterprobe, project above ground. A combination of of 5 to 10 stati activated for each of the Bikini shots. 3.2.3 Remarks Project laboratory space will be provided on Elmer and all electronics will be processed there and transhipped to Tare. In addition, an 88 eurie and 4 and 5 curie sources will be on hand for calibration necessary for Projects 2.1 and 2.2. These sources will 27