‘4 2.3 PROGRAM 3, SCIENTIFIC PHOTOGRAPHY This program had many objectives, each of which involved photographic documentation of some aspect of the detonations. Fireball growth, cloud development, and illumination vs time were measured for both shots. For Mike Shot_ and the crater structure were documented, and - For King Shot the precise position of the burst was measured. In addition, bhangmeters (detection of fireball light) were utilized for both shots. These instruments were designed to obtain a remote and quick yield result from light-signal observation. Generally speaking, three camera types were used to accomplish the photographic objectives, one type producing a record made up of a number of discrete photographs (or frames), another producing a continuous streak record, and a third producing a single picture at a known time after zero, Depending on the phenomenon being photographed, film speeds from 16 frames/ sec to 3%, million frames/sec were utilized. Many data were obtained in spite of isolated equipment failures. Most of the film records have yet to be completely analyzed, but preliminary analysis of the fireball-growth films indicates the following yield values: Mike Shot, 12 + 2 Mt; King Shot, 570 + 30 kt. (See footnote on p. 7.) oo The King Shot burst position was determined to be: Calculated error in position, 570 + 35 ft; height of burst, 1480 + 20 ft. 2.4 PROGRAM 4, NEUTRON MEASUREMENTS Program 4 was primarily devoted to the measurement of total numbers of neutrons, in various known energy ranges, arriving at fixed points on the ground. Such neutron counting is accomplished by laboratory analysis of the neutron-induced radioactivity in selected thresholddetector materials such as gold, tantalum, indium, fodine, and zirconium. For each shot many detector stations were established in radial lines extending outward from bomb zero. In addition, an attempt was made to measure the total number of neutrons arriving at a few selected points as a function of time, utilizing a device known as the “fission-catcher camera,” The basic difference between these two measurements should be noted, Thefirst allows only a counting of neutrons and gives no information as to when a particular neutron arrived, whereas the second does allow such a time separation. Since the detector-station positions for Mike Shot were selected on the basis of an expected relatively low yield, many of the samples were lost. However, 35 samples were recovered, some from within the weapon crater, and are being analyzed at the present time. Thirty-eight of the King Shot samples were recovered and are also undergoing analysis. All the fissioncatcher cameras were destroyed by the blast. Incidentally, the relatively large amount of measurement-station destruction (and resulting potential data loss) suffered by this program is not indicative of a poorly designed experiment. The high attenuation of a neutron signal passing through air dictates that such stations must be relatively near the bomb, and the value of such close-in data is well worth the risk of losing an inexpensive station. Also, one of the great potential values of these neutron measurements is to explain why a device fizzled or detonated with a yield much lower than predicted. 2.5 PROGRAM 5, GAMMA-RAY MEASUREMENTS This program was another of those devoted to studying the phenomenology of the device tested. Measurements were made of the gamma-ray intensity as a function of both time and distance, including that due to fall-out, and of the total gamma-ray dose as a function of distance. The close-in instrumentation was also designed for diagnostic studies and a study of shock-wave effects on gammaradiation, The more distant instrumentation was concerned 10