The thin Panatamic X film worked quite well in the radiation field of the bunker, The film shows about 3 or 4 roentgens total dose, Unfortunately, the color film had no color calibration on it and therefore the degree of coloring of the fireball will not be known, Development of the Panatamic X film was 2 minutes in the Berry developer BD7B and the color film was processed 5 minutes in D-76, | All the cameras operated to give excellent results, The four streak cameras to study expansion velocities of the early fireball gave the records shown in Figures 1 to 4, oo eo gy” ‘Expansions to the right were seen through two inch slots built in a baffle on the tower, Expansions to the left were seen in a cancra slit which was projected on the cab to a width of 6 inches, slit in the camera is shown on the film whe The angle of the ee ee The width of the slit image is only slightly widervthan its geometrical size, Therefore, the recordable — t lasted only a short time, probably less than end ee a ES Le ey a cae ee aaa: -. ~ \\ evidence that an absorption cut-off Teller light too early. ee x i‘ there is The exposure on the right side as seen through the 2 inch slots was much less than the exposure on the left side, side. Figure 2 shows very Little exposure on the right One expects a factor of two between the two sides because of the effective slit sizes, but the exposure indicates a factor of at least ten. Various studs in the baffles, rails, etc. show in the pictures as shadows, The studs in the slots accuretely show the scale of the record in the space direction. Copylg tai, ong -70- Guy

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