(U) Gamma measurements were mad? by SRDL (Referen ze Force School of Aviation Medicine (SAM) (Reference 51), Ai cial Weapons Center (AFSWC) (Reference 52), EG2G (Reference 53), ant a number of different agencies for Program 2 during Shot LaPlace (Revsre:ce 54). (2 v) $ ) AFSWC measured the variation in gamma dose with heigh aocve- a ground Sing a variety of detectors an? found that the gazca dose increased by about a factor of 1.3 at an altitude of approximately Loc feet. They deduced that the initial gamm2 radiation is nearly moncilrectiocal and vat that the bulk of the scattered radiation is of low Sel enerzy. Selectei NS film badge and chemical dosimeter (SAM) data at 3-foot height sented herein to supplement the other gamma data, Hurst and Riteh! (Reference 55), using fission foils and chemical dosimeters in col confirmed that the angular distribution of the neutron and gam? at the ground was insensitive to,weapon and distance ard that ‘the buildup was approximately 30 percent. Wt other gamma data were available. “EG&G used a weak film ” develoe? r, Kodax D-76; the neutron effect on film is impossible to determine when this developer is used (Reference 56). position and type of stations. the NBS film badge. Information was also lacking The EG&G film badge is ver; similar to ning (U) The SAM used the tetrachhoroethylene two-ph ase chemical dosimeter to measure the initial gamma dose. The dosimeter is claimei to be fast-neutron insensitive; that is, if exposed to one rep of fast neutrons with no gamma rays present, the. dosimeter would generate 0.83 vercent as much acid as it would for 1 r of gamma radiation. Therefors, no corre:tions are necessary for fast-neutron sensitivity. The dosimetsr is thermal-neutron_sensitive. Reference 10 reports that 5.9x10° thermal neutrons per ene produce as much acid as 1 rep of gamma rays. During this operation lithium shields in 1/4-inch-thick aluminum "Beer Mugs" were used to reduce the thermal-neutron flux. Page 23 of Reference 51 states, "If no gamma rays are present, 3.25x10'* thermal neutrons generate as much acid as 17r of gamma rays in the two-phase tetracnloroetrylene systen." J This is erroneous since it conflicts with statements in Ref SLEnCE | 10 b the same author and with Reference 57 which states the® 3.25 “10°? thermsi neutrons generate as much acid as 17r of gamma rays wren the dosimeter is encased in the lithium shields. Corrections for thermal-neutron W220 al ve not made when the dosimeter was encased in lithium. [SeoL The ta effects were chemical dosimeters in the “Beer Mugs" were hung from steel gcai zosts at approximately 3 feet above the ground, (U) SRDL exposed film in NBS holders to measure gamma dose. Most of the film was exposed in the photographic-dosimeter transport mecharisn (Emmett) designed to measure gamma exposure in one-second increments 38