The rockets were caged in position on the launchers during all events until the shock wave passed. In Figure 2.2, all rockets were caged except the one in the lower right-hand corner, on which the caging clamps stand open and are visible just above tne supporting A-frame. The cages were closed with explosive bolts, whose detonation by the timer just prior to launching uncaged the rockets. Nine rockets were expended making preoperational flight tests and obtaining trajectory information. Figure 2.3 is a plot of range versus altitude for various quadrant elevations of launching of the rockets from sea level in a standard (National Advisory Council for Aeronautics) atmosphere. Time marks are indicated on the trajectories. Trajectories were calculated from information gathered at test firings at the Naval Air Missile Test Center, Point Mugu, California, and at White Sands Proving Grounds, New Mexico. Four rounds were fired at Point Mugu and five at White Sands. Of these, eight were fired at a quadrant elevation of Y, radian (28.6 degrees), and one, at an elevation of v4, radians (85.9 degrees). Rockets were tracked by photothcodolites, skin-tracking radar, and velocimeters (doppler radar). The velocimeter and phctotheodolites were able to track the rockets to burnout, whereas radar tracked them to impact. One test rocket was fired in the field in conjunction with the Shot Cherokee dry run to check out the complete system, including the Site How launching station and the Site Nan and USS Knudson receiving stations. The USS Knudson was stationed at a point which was ac the same general bearing and range relative to the test rocket trajectory as tne planned trajectories tor Shot Cherokee. Goodsignal strength was received at both reveiving stations. 2.2.2 Radiation Transducers. The transducer (Figure 2.4), composed of the ionization chamber and the blocking oscillator circuit, was assembled as a single compact unit and mounted in the forward part of the ogive of each rocket. The ion chamber-electrometer devices were capable of measuring gamma radiation at dose rates from at least 10,000 r/hr to less than 10 r/nr with an energy response of 0.1 to 2.0 Mev. The electrometer circuit was designed to operate in a cyclic mode to produce pulses directly preportional to the dose rate. The pulses modulated the telemetering FM transmitter (Ralph M. Parsons Company Model 7501,, which supplied 2 or 3 watts to the antenna (a TYs-inch spike protruding fromthe nose of the rocket). The ton chamber had the following characteristics: Type of construction - Parallel-plate guard ringed Gas and pressure ~ Pure Argon, 15 atmospheres Collecting volume ~ Nominal 100 cc Maximum radiation rate ~ 10,000 r/hr Current output - Nominal 107" amps/r/hr High voltage electrode voltage ~ 180 volts Number of plates - 4 HV, 3 collecting Collecting-to-HV electrode capacitance - 40 to 50 ypf Plate spacing - 0.48 cm Beta response - None The energy response of the chamber alone was not specified, as it was measured as a function of direction over the entire 47 solid angle as installed in the rocket. The electrometer circuit was the simple blocking oscillator shown in Figure 2.4. Its operation may be briefly traced as follows. If a pulse has just occurred, the grid of the electrometer tube is at a negative potential of 10 to 15 volts with respect to ground and completely cuts off the tube. Ionization caused by gamma radiation incident on the chamber discharges the chamber capacitance; since the ion chamber is completely saturated, the discharge is linear with respect to time. As the grid voltage rises, the tube gradually reaches a critical trigger value, at which time rezeneration occurs through the chamber capacitance. Th chamber is recharged by grid current as the pulse occurs; when the pulse falls, the grid diode action ceases and the grid re- sets to the negative cut-off potential. Each pulse out represents a certain increment of dose, so the repetition rate of the pulses is proportional to the dose rate. The nominal pulse-rate of the circuit was 0.2 pps/r/hr, so the upper pulse-rate at 10,000 r/hr was 2 kc and the incremen15