ground units when supported by tactical atomic weapons and to determine the psychological reactions of troops particf{pating in the exercise. The DOG tactical maneuver was the first Marine Corps maneuver of the CONUS tests. In addition to these activities, Exercise Desert Rock IV involved psychological tests at CHARLIE, FOX, and GEORGE to gauge the troops’ reactions to witnessing a nuclear detonation (9: 1,5). Figure 9 shows troops advancing into the test area behind a radiological safety monitor on 2 May 1952, 1 day after the detonation of DOG. The troops halted as the monitor took measurements with a Geiger Counter (B). 4.7.3 Dose Summary for Operation TUMBLER-SNAPPER. A dose limit of 3.0 rem of gamma radiation per 13-week period was established for participants in Exercise Desert Rock IV, the joint AEC-DOD organization (coordinator of the series), and most of the Air Force Special Weapons Center (AFSWC) activities (9: 7). The following table presents the available dosimetry information: Summary of External Doses for Operation TUMBLER-SNAPPER as of 1 May 1986 Gamma Dose (rem) 0-0.5 0.5-1 1-3 3-5 5-10 10+ Army 3,848 467 61 17 6 1 Navy 446 45 61 4 0 0 Air Force 1,112 35 42 17 3 0 Marine Corps 2,033 8 1 0 0 0 Civilian DOD Participants 368 43 82 10 0 0 92