=.APACHE) + Project 22,2 - Messurenent of Primary Alpha and Nuclear Tine Interval - A. Crier E, C, Woodward om DESIGN OF THR EY PERIMENT The device was located on a barge in the Mike crater some 750 feet from Station 1611 on Bogon, Eriwetok Atoll, One LASL fluor - photomultiplier a detector, one UCRL fluor - photomultiplier detector (containing two banks of photomultipliers) and three EG&G fluor- photodiode detectors were used to view the parma radiation from the device, Some collimation was provided by pipes 24 inches in diameter in front of the detectors some 20 feet long and covered with about 5 feet of earth fill, The pipes in front of the LASL photomultiplier detector and the most sensitive photodiode detector were stopped town to about 1? inches. It was desirable that the prirary signal strength could be better underatood, and that the results could be correlated with the , (Lacrosse) results, Therefore, a lead shield approximately five feet Bquare and several inches thick with a central four inch diamcter hole on the line-of-sipht between the primary of the device and the detectors was installed on the barge about aix feet from the device, The syatem waa desipned so that the sifpnals from the photomultiplier detectors and the most sersitive phototiode detector would provide information on the operation of ‘he BE 2 and the two less sensitive photodiode Jetectors YT Soe would provite nuclear time interval information on tneMEPscecne) device, SNL 3 - £2 - 42.