Abstract: "The leakage neutron spectrum of a U²³³ spherical critical assembly (Jezebel) has been measured using nuclear emulsions as radiator and detector. The spectrum obtained is compared with similar measurements on the U-235 and Pu-239 analogues of Jezebel U²³³; it is found to agree closely with that of the Pu-239 assembly and to be harder than that of the U-235 assembly. All three spectra are compared with theoretical spectra obtained from a numerical approximation to the neutron transport equation."

Abstract: "The calculation of the efficiency of the Los Alamos hydrogen bubble chamber for detection of neutrons in the energy range 5 to 35 MeV has been done using a "Monte Carlo" technique. The detection efficiency is calculated as a function of energy of the neutron and angle of the proton recoil."

Several of the plutonium assay methods were reexamined as part of a continuing effort to make improvements in these frequently used analyses. This investigation included a study of the controlled-potential coulometric, amperometric, potentiometric, and photometric titration methods and their applications to assays of delta-stabilized and alpha plutonium metal.