The bibliography provided investigates the following sources: Chemical Abstracts 1947-1950., Metallurgical Abstracts Vols. 1-18., ASM Review of Metals Literature Vols. 1-6., J. Institute of Metals Vols. 78-80 (No. 7)., Physics Abstracts 1937-1950.

"This report contains information on the following topics related to the radiation shielding at test cell "C". (1) Calculation of wall and roof thicknesses. (2) Calculation of radiation heating of front wall by gamma and neutron absorption. (3) Calculation of neutron activation in front face of test cell. (4) Calculation of γ-dose rates both direct and behind shadow shields at various distances. (5) Dose produced by a reactor catastrophe."

Preface: This report contains data and information on the resurvey effort and the effect of residual contamination as a result of nuclear weapons development programs conducted in this area.

Multivariate statistical analysis to support the National Uranium Resource Evaluation and to evaluate strategic and other commercially important mineral resources

Report of uranium and thorium findings from a reconnaissance of the Casper NTMS quadrangle through water and sediment samples analyzed for uranium elements by delayed neutron counting and fluorometry, thorium, and 41 additional elements by neutron activation analysis, x-ray fluorescence, and arc-source emission spectroscopy.

Final report describing the development and usage of an automatic decade scaler which operates for a fixed number of counts, developed for use with a Geiger tube.

Report of reconnaissance of the Albuquerque NTMS quadrangle through water and sediment samples collected from springs, wells, and streams. Samples analyzed for uranium and 42 other elements. This report is limited to samples containing uranium concentrations greater than the arbitrary anomaly thresholds of 5 parts per billion for waters and 6 parts per million for sediments.

From introduction: This report describes the results of water and sediment sampling within the New Mexico portions (or western halves) of the Hobbs'and Brownfield, New Mexico/Texas, National Topographic Map Series (NTMS) 1:250 000-scale quadrangles.

From introduction: This report describes work done in the Tularosa, New Mexico, National Topographic Map Series (NTMS) quadrangle (1:250 000 scale) by the Los Alamos Scientific Laboratory (LASL) as part of the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR).

Report describing the analysis of water and sediment samples taken from the Cheyenne quadrangle in Wyoming to determine if they contained uranium. Several areas were identified for further study, based on initial analyses.

Abstract: Multivariate statistical analyses were carried out on Hydrogeochemical and Stream Sediment Reconnaissance data from the Craig quadrangle, Colorado, to support the National Uranium Resource Evaluation and to evaluate strategic or other important commercial mineral resources. A few areas for favorable uranium mineralization are suggested for parts of the Wyoming Basin, Park Range, and Gore Range. Six potential source rocks for uranium are postulated based on factor score mapping. Vanadium in stream sediments is suggested as a pathfinder for carnotite-type mineralization. A probable northwest trend of lead-zinc-copper mineralization associated with Tertiary intrusions is suggested. A few locations are mapped where copper is associated with cobalt. Concentrations of placer sands containing rare earth elements, probably of commercial value, are indicated for parts of the Sand Wash Basin.

From introduction: Reported herein are uranium and other elemental data resulting from the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Newcastle National Topographic Map Series (NTMS) quadrangle, Wyoming, by the Los Alamos Scientific Laboratory (LASL).

A sphere of LiD 2 feet in diameter was irradiated by 2 x 10<sup>15 14 Mev neutrons. Samples of Li<sup>7 metal were positioned at various radii for the irradiation. An analysis of these samples for tritium led to a determination of the number of tritons produced by 14 Mev neutrons acting on Li<sup>7 in a LiD system.

A measurement of the [Lithium-7] reaction cross section by absolute counting of the tritium betas is described. The cross section was measured at several neutron energies between 4 Mev and 15 Mev. A comparison with results by emulsion techniques is given.

This report describes the construction, operation, and typical uses of Topsy, the versatile, remotely controlled, critical assembly machine at Pajarito. Section 1 covers the mechanical design of the machine, and the hydraulic and electrical operation of the various components. Section 2 describes how Topsy is used for investigating reacting metal assemblies. Procedures for establishing a delayed critical configuration and operation at delayed critical are illustrated for the oralloy-tuballoy system. Also included are brief descriptions of oralloy-nickel, plutonium-tuballoy, and low density and concentration assemblies that have been made on the machine.

The production yields of hydrazine by various ionization methods are compared. The maximum value of M/N (number of molecules reacting per ion pairs) for electric discharge was 0.25 and for beta particles on liquid ammonia, M/N = 0.31. A 1-Mev reactor could produce 1.6 kg of hydrazine per hour if M/N = 0.04 as determined by alpha particles on liquid ammonia. About 300 ev of energy were needed to form a hydrazine molecule. (C.J.G.)

This report brings together an extensive accumulation of material replacement (danger coefficient) data for the various oralloy critical assemblies at Pajarito. Corresponding values of effective absorption and transport cross sections are derived. In certain favorable cases, inelastic scattering contributions to the effective absorption cross sections are estimated. Special applications of material replacement data include computation of the relationship between oralloy critical mass and concentration of a diluent and hydrogen isotopic analysis of heavy water and heavy polythene.

Optical and morphological properties of 28 compounds of uranium, plutonium, americium and some related elements, belonging to 21 isomorphous groups, are described. Additional data are given on 5 compounds of similar type described in the National Nuclear Energy Series, Division IV, Volume w, Chapter 19, “Actinide Elements.”

Neutron detector traverses of the untamped Oy (Godiva) and the Tu- or Ni-tamped Oy (Topsy) metal critical assemblies have been obtained by counting the following types of radiation : 1) y-activity of U 235 and U238 fission products; 2) fission fragments of Np 237 in a spiral chamber; 3) and Beta -activity of Au and S. At a few positions within the assemblies, and for the U235 fission spectrum, cross section ratios of a number of pairs of fissionable isotopes were determined by means of a comparison fission chamber. At the center of Godiva, af(25)\af(28) = 6.2, and this ratio for the Topsy Oy-Tu assembly ranges from 6.8 at the center to 76 at a radius of 8-1/4”. Results of radiochemical analyses for fission and other reaction products, by Group J-11, are listed in an appendix.

The increased use of tritium monitoring devices has made it necessary to devise a scheme for the calibration of such instruments. Several methods for setting up known concentrations of tritium were considered. A dynamic system containing tritium as HTO vapor or gaseous HT was selected because of the ease of control of variables. The variables that have been considered are: ,1. The effect of rate of air flow through the instruments. 2. The effect of humidity on instrument response. 3. The effect of ion collection ahead of the ion chamber. 4. The variation of “hold time” from the generation of tritium to its passage through the ion chamber. 5. The instrument response to several concentrations of tritium as HTO vapor and gaseous HT. The following three types of monitoring devices have been calibrated:1. Model 101 Sniffer of Group P-1. 2. Cl-1 Vibrating Reed Electrometer of Group CMR-7. 3. Modified TIB of Group H-6.

The development of sampling methods and some field results of the off- site air sampling stations at the Nevada Proving Ground are reviewed. A technique of radioautography is presented which yields information about the activities of individual fall-out particles. This technique gives a comparison of particle activities from air drops and tower shots and a reason for the greater contamination associated with the latter. It also indicates that air samplers do not capture the most active fall-out particles, presumably because of their large size.

Detailed study of the mathematically developed end-point method and its application to the Milne kernel.

"Data analysis to evaluate uranium and other strategically important mineral resources was carried out on Hydrochemical and Stream Sediment reconnaissance data from a selected region in south-central Alaska."

The work of the Laboratory has greatly expanded into applications of nuclear energy which are significant for national defense and security, but are not directly connected with weapons development. It was felt, therefore, that a description of the non weapons activities of the Laboratory would serve a useful purpose at this time. For classification reasons, it has been necessary to issue the report in three parts; the third part concerns power reactor experiments.