Chapter 3 RESULTS and DISCUSSION This chapter presents raw data based on Co”calibration and discussion necessary to clarify the tables. The terms thermal, blast, 1-minute, total, and rate device refer to timing (Sections 2.2.6 and 2.2.7), and down refers to dosimeters that were placed in the bottomof the pipe stations. The termsfront, left, rear, and right refer to instruments wired flush to the outside of the stations, with respect to an observer at ground zero facing the station. Instrumentation and recovery rates refer to residual gammafield intensities at the times of instrumentation and recovery of instruments located at an exposure station. 3.1 SHOT LACROSSE One piece of initial-gamma exposure data was obtained on this event at a Project 2.65 station on Site Yvonne. Initial (total exposure) was 5.3 r, distance 8,088 feet, yield 38.5 + 3 kt, and relative air density 0.893. Instrumentation and recovery rates were negligible. 3.2 SHOT CHEROKEE All stations other than those listed in Table 3.1 received less than! _ Film at the Series 250 and 251 stations was damaged by water or sulphur fumes from damagedneutron-threshold detectors. Therefore, the results were not included. The exposures at the stations listed in Table 3.1 were possibly from initial-gamma radiation. Temperature effects on the film could have caused an increase in background density, as discussed in Section 2.2.1, However, careful re-examination of all data did not reveal any such temperature or aging effects present in the Shot Cherokee data. The presence of low-energy gamma components in the residual field was indicated by the higher exposures measured by films exposed without NBS holders. The instrumentation and recovery rates were negligible. 3.3 SHOT ZUNI Table 3.2 lists the total exposure on Shot Zuni. the same shot. Table 3.3 lists the initial gamma exposure for Eight-inch steel-pipe stations were installed at Stations 210.23’, 210.27’, 210.30’, and 210.34’. The rate device at 210.27’ became wedged in the station and failed to drop. .The “1 cap of Station 210.30 was broken by the shock and the instruments fell immediately. [_. —-— 6 Another rate device at Station 210.34’ without a dropping mechanism yielded only total exposure information. . A mechanical drop mechanism installed in a water-filled steel pipe at Station 210.23’ functioned properly because the dosimeters were dropped in correct sequence. The water was used for additional shielding, since the depth of the instrument mount was only 2 feet below the surface. The initial-gamma exposuresfor this event were lower than anticipated; moreover, the gamma exposure was lower than expected for the measuredyield. All the film that dropped read less than Ir. 3.4 SHOT FLATHEAD Tables 3.4 and 3.5 list instrumentation and recovery and initial exposure, respectively, for Shot Flathead. The disparity between the film and quartz-fiber exposures at Station 212.03 was 29