The total thickness of lead a top of the collimator was probably lees than 1". The lines of sight through the blast plete were protected by 12" 1,D, pipe about 8° long wuded to the front of the plate. these pipes lead wool was packed to a thickness of about 4". Around The front, tep, and sides of the collimator were protected by several layers of sand bags. The 300 yd station contained three phonex cameras having polysthy- lene radiators 0,001", 0.0025", and 0,003" thick. Ilford nuclear eml- sien plates were used at the rear smal) angle positions only. The four plates in each camera were as follows: 3004C2, 200~C2, OOAE], and 200AB. The cameras at the 600 yd. station were similar except for one. Instead of a 0.003" polyethylene rediator at the front of the camera, a Geuteropareffin rediator wes used at the rear. This camere wes used by Lowis Eosen to look for the angular distribution of protons from the photodisintegration of the deuteron. Cameras were recovered from the 600 yd. station sbout mid-afternoon of En~day, Development of the plates fran Rosen's eamera and from the 0.0025" radiator camera was strrted immediately. The C2 emulsions gave good readable plates reasonably free of background. The BE) emulsions, Q@lthough showing leas background, do not show at all well the beginnings of proton tracks whose energies are greater than about 10 or 12 nev. Two hundred and eighty-one tracks were neasured on one of the C2 plates by Louis Rosen. The resulte of this analysis are show in Table 122-1 and the neutron energy spectrum extrapolated back to the outeide of the beab is show in Meg. 12,2-1, The cameras from the 300 yd. station were recovered three days later. ~Eerr “37% BEST AVAILABLE COPY &:.- +. 47 ge