Abstract: "A description of the demand computer and its functions is given. Methods of testing and adjusting, and gain and response curves for the system and its parts are included."

Abstract: Both direct and coincidence counting apparatus are described. The elimination of cosmic ray events by coincidence plus gamma ray shielding permits the reduction of counting rates far beyond that obtainable with shielding alone. By selection of materials and development of new components and techniques, the residual background count of beta counting equipment can be reduced to a very low value. Geiger counter equipment for routine laboratory measurements is described, have a background count of 0.7 c/m. Scintillation counters are shown to have a background of 0.2 c/m at 30% efficiency. A portable Geiger counter with a 3.7 c/m background is also described.

Abstract: This report presents metallurgical .analyses and corrosion tests conducted to determine :causes of failure of two SM- 1 reactor vessel studs due to fracture in the threaded areas, after 23 months' operation (March 1959). Conclusions of corrosion tests are: (1) failure of the studs was caused by stress corrosion cracking, (2) contributing factors to failure of the studs were improper control of heat treatment of the studs and absence of treatment for stress relief after thread grinding operation.

The design of the present time of light mass spectrograph is similar to that of the isotron devised some time ago for isotope separation. The spectrograph will employ the time of flight principle only for the isotopic analysis of small samples.

Abstract. a method of recovering thorium from slag from the bomb process of producing thorium has been developed. HCl and NaOH are the only chemicals required in quantity. Materials required for a representative slag are given.

The Lindemann assumption of direct contact of neighboring atoms at fusion is replaced by the criterion that melting occurs when the root-mean-square amplitude of thermal vibration reaches a critical fraction ρ, presumed the same for all isotropic monatomic solids, of the distance of separation of nearest-neighbor atoms. The Debye-Waller theory of the temperature dependence of the intensity of Bragg reflection of x-rays is used, without further assumptions, to derive a generalized Lindemann law. In contrast to the Lindemann form, all physical quantities involved in this formulation are evaluated at the fusion point, and departure of the average energy of an atomic oscillation from the equipartition value is taken into account by the quantization factor of the Debye-Waller theory. If the Grüneisen constant γm of the solid at fusion is evaluated by its definition from the Debye frequency of the solid, use of the generalized Lindemann law and Clapeyron's equation permits one to express γm in terms of the bulk modulus of the solid at melting and the latent heat and volume change of fusion. By means of Grüneisen's law applied to the solid at fusion, γm can be expressed likewise in terms of the corresponding bulk modulus, thermal expansion, volume, …