Quarterly progress report describing work related to a study of radiation physics problems involved in the design of high-level cesium-137 gamma sources. It outlines work completed and ongoing goals for the project.

This report studies tritium oxides and tritium in water vapor, a product of P-10.

From introduction: "This article constitutes the third of a series of three papers on the "direct" measurements of the meson masses by the "Hp vs. Range" mass ratio method...The study here reported is a logical extension of the pion-proton mass ratio technique."

The following report analyzes results from studies made while applying chelating agents to ion exchange separations of the elements americium and curium.

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.

it is desired to know the accuracy and precision of uranium content determination with the γ-photometer. Several possible sources of error (involving both bias and variability) arise when the problem is fully considered. As analysis of data collected for the evaluation of this technique has progressed, there has been a continued discovery of new sources of error and bias further complicating this evaluation. These possible sources have not yet all been systematically examined and thus a complete answer cannot be given at this time. The following is an attempt to state the problem and make recommendations concerning its over-all solution. These recommendations are not assumed to be the totality of those possible; however, they will provide a starting point.

Various methods and procedures for preparing uranium dioxide bodies for metallographic examination and study have been utilized by various investigators. Unfortunately, these methods are not in general satisfactory for use on irradiated uranium dioxide. Since radiation damage studies on irradiated uranium dioxide require use of electron microscopy, and reveal structure by virtue of surface relief. This report covers an investigation of etching methods compatible with radiometallurgy and electron microscopy requirements.

This report discusses the mathematical and statistical questions concerned with the estimation of a leak rate from data collected during a reactor containment vessel pressure test such as that performed on the PRTR vessel in May, 1959. A mathematical method is suggested in Section 3 for the construction of a total number of gas molecules in the containment vessel time series using vessel absolute pressure and temperature readings at several positions within the vessel. A formula for the precision of the series is given in terms of the individual instrument precisions. The question of accuracy and its relationship to the temperature gradient within the vessel is also considered.

The feasibility of removing and recovering cesium-137 from various HAPO process solutions by precipitation of Cs2ZnFe(CN)6 has been demonstrated previously. Pilot plant studies of calcination and steam hydrolysis of non-radioactive Cs2ZnFe(CN)6 precipitates by members of the Process Equipment Development Operation are currently in progress. In support of these pilot plant studies, experiments were performed to determine the extent, if any, to which cesium volatilizes during calcination and hydrolysis of Cs2ZnFe(CN)6 precipitates containing cesium-137. Experimental procedures and results are presented in this report.

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, …