— @ Project 22,1 - Resection History - L. F. Wouters B.C. Woodward THE The gamma rays produced by the nuclear reactions were detected by flour photocell detectors located in a lead lined detector pit located near the recording station some 2750 feet from the device. Collimation was provided vy a 10 foot high ty 12 foot wide wall in the osb consisting of 6 inches of It lead and 12 inches of paraffin vith eppropefately shaped holes for the primary and secondary rediation to pass to the detectors, two collimating disks an short towers between the device and the detector pit, and a 27 foot leed pipe attached to the detector pit. The disks and pipe restricted the view of the detectors to the wall and the portions of the device observable through the ° two boles in the wall. ‘The primary bole was covered with 3.2 inches of lead in order to extend the possible range of coverage of the secondary. Four flucre vere positioned in tandem along the collimated gaam= path and were observed by a total of three photodiodes and four protomltiplier unite. Appropriate combinations of samme attenuators betveen fluores aad optical attenuators between different detector units on tre seme flucr sade possible the complete coverage of a dynamic renge of 107°, The detector outputs vere trangnitted by eable to some 35 ocscillographs located im the recording station where cameras provided a permanent fila record of the signals. RAL figh Explosive + Time = The high explosive transit time vas seasured to a the beginning of the Xnunit load ring pulee ® | to the time of the 50th generation level of the primary fiesion reaction, BLE coPY Best AVAILA ~- «5 « can ELYDOE SENDA RC 6S