The neutron sensitivity of film is considered to consist of two components, a response to lowenergy (thermal) neutrons, and a response to high-energy neutrons, As far as could be deter- mined from the experiment, the two components were independent and additive. The calibration ‘data for neutron flux was furnished AFSWC by N-2 division at LASL. It was assumedthat any TABLE 2.5 FILM SENSITIVITY TO NEUTRONS See Section 2.3.1 for source of data. DuPont Film Packet ° Type 606 1290 606 510 502 606-1290 606-1250 553 553 553 Low Energy (Gold) Neutrons High Energy Neutron Dose (n/em’) r x 1073 n rep dose/r 4.74 3.9 + 3.44 2.34 3.24 2.4 2.2 1.8 1.4 1.7 37 + 22 31 + 20 28 +17 19412 26415 perturbation in flux caused by the NBS film holders would be small. Neutron-sensitivity values were compared to the amount of Co*? gamma radiation required to produce the same optical density. Table 2.5 summarizes the data obtained. For all shots except Cherokee, the relative air densities were 0.895 + .002. For Cherokee it was 0.847; however, the data were adjusted to a relative air density of 0.895 to permit comparison of results. No air-density adjustment was made for the other events. In analyzing the initial data to determine the flux that existed outside the station, it was important to take into account the attenuation offered by the station and the instrumentation inside. Table 2.6 presents a list of station types and calculated shielding correction factors based on a 3.5-Mev gamma energy in accordance with the assumptions of Reference 25. A mutual instrument~shielding correction factor for each station type was estimated and is given in Table 2.6. TABLE 2.6 INITIAL-GAMMA-EXPOSURE CORRECTION FACTORS . . Station Series 210 Station as Shielding Mutual aa Shielding Combined Quartz . . Fiber and Chemical , Correction Factor Betatron Film as Normalization Combined Film . Correction Factor 210' without quartz . 1.05 . 1.05 . 1.10 ‘ 0.90 0 £0. 1.0 0.05 211 fiber rate 212 device 1.35 1.10 1.48 0.90 1.35 + 0.10 1.40 1.15 1.61 0.90 1.45 + 0.10 213 1.20 1.05 1.26 0.90 1.15 + 0.05 118 1.15 1.05 1.21 0.90 1.10 + 0.05 210' with quartz 211 fiber rate 212 device An experimentally determined film betatron calibration factor of 0.9 is also listed. The com- bined correction factors were computed from the above-mentioned factors. The betatron calibration factor applied to the film only. No betatron calibration data were available for the quartz fiber and chemical dosimeters, and a factor of 1.0 was assumed. 23