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Leakage Neutron Spectrum of U²³³ Critical Assembly

Description: 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."
Date: September 1962
Creator: Bobisud, Larry E.

A Monte Carlo Calculation of the Neutron Detection Efficiency of a Hydrogen Bubble Chamber

Description: 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."
Date: September 1962
Creator: Wooten, J. K. & Bryant, H. C.

Equations Representing Reactor System with Emphasis on KIB Digital Program

Description: "This report is written as a supplement to LAMS 2539. It is hoped that one will be able to read LAMS 2539, with emphasis on the fourth part (Memorandum N-4-79OU by 0. Farmer), with this memorandum to bridge the gaps and understand more about the model used and what the KIB Program can be used for. The system is defined by subsystems or subprograms: Thrust System, Heat Exchanger, Neutron Dynamics, Rod Actuator Dynamics, and Thermocouple Dynamics. The original Kiwi-B Flow System is included in the first part of LAMS 2539. This has been replaced by the newer system which includes a turbo-pump (per R, Bohl & E. Wheatley). This system will not be included here. Recommendations are made for improvement and more work in certain areas."
Date: August 29, 1961
Creator: Mohler, Ronald R.

Instrumentation and Some Related Problems for Neutron Flux Measurement of the Los Alamos Scientific Laboratory Kiwi-A Reactor

Description: Abstract: "A description of the instrumentation for neutron flux measurement from Kiwi-A at NTS is given as some discussion of start-up considerations, detector design, system response adjustments, and power calibration of the reactor at some low level of power."
Date: September 1958
Creator: Barton, David M.; Helmick, Herbert H. & Jarvis, G. A.

On the Possibility of Extracting Energy from Gravitational Systems by Navigating Space Vehicles

Description: This report describes a number of problems, generally involving the possibility of using reserved kinetic energy in such a way as to acquire, by suitable near collisions with one or the other of the celestial bodies discussed, much more kinetic energy that it possesses -- more by an order of magnitude than the available reserve energy would allow it to acquire by itself.
Date: 1958
Creator: Ulam, Stanislaw M.

A Survey of Some Los Alamos County Canyons for Radioactive Contamination, Spring 1953 to Spring 1955

Description: Abstract: This document is a survey analysis of soil samples from Los Alamos, Pueblo, Bayo, and Mortandad canyons to determine the presence and activities of radioactive contaminants. Also included are the results of analyses of a few samples of grass and of surface water. This survey covers the period from spring 1953 to spring 1955.
Date: April 1956
Creator: Dodd, Aubrey O.

Influence of Gamma Irradiation on RG 8/U Cable

Description: Abstract: "Static measurements have been made of the currents produced by Co-60 gamma irradiation of solid dielectric RG 8/U cable. Sensitivity curves are presented as a function of the magnitude and polarity of the collection voltage to 90 volts. It is shown that the current is due to a polarity- and voltage-sensitive ionization component and to a polarity- and voltage-insensitive component attributed to the Compton process. The total cable sensitivity at -90 volts, with saturation not achieved, was (11 +/- 1) x 10-(-12) coulomb per roentgen-meter of cable, or 0.08 percent of what one would expect from ionization in an air dielectric cable of this volume."
Date: November 1955
Creator: Kloepper, Robert M.

An Optical Fallout Analogue

Description: This report describes the optical analogue that contains an optical filtering system which controls the intensity of light according to the assumed initial distribution of activity over height and particle size and according to the assumed decay rate, a size control system which depends on the lateral dimensions of the cloud of debris and adjusts the size of the light beam accordingly, and a position control system which moves the beam to the correct position on the plate as determined by the wind structure and the time of fall of the particles.
Date: October 1955
Creator: Felt, Gaelen L.

Estimated Upper Bounds to the Half-Life of Thermal Decomposition of Ammonia, Hydrogen, Methane, and Propane

Description: An estimate was made of the upper bound for the half-time of dissociation at 100 atm for ammonia, methane, and propane at 2500 deg K and hydrogen at 5000 deg K. In each case a unimolecular reactron in the homogeneous gas phase was chosen as most suitable for this purpose. Slater's theory has been used to estimate the necessary frequency factors. The upper bounds to the half- time for dissociation range from 3 x 10⁻⁷ to 6 x 10⁻⁶ sec. Extrapolation of decomposition rate data obtained at --1000 deg C and 1 atm pressure gives smaller values for the half-time of dissociation.
Date: August 1955
Creator: Herschbach, Dudley R.

Fall-Out Studies with a Laboratory Controlled Model

Description: From abstract: "To seek information for a better understanding of the phenomena involved in fall-out, a fireball effect was simulated in a small closed room by subjecting various materials to a high-current (~360 amp.) are produced between graphite electrodes, and anode being impregnated with radioactive materials. The time duration of the arc, power dissipated, and distance from the samples were controlled. The radioactivity which remained airborne, that which settled out onto the floor and its distribution, and that deposited on the test material was measured, and percentages of the total measured activity were determined."
Date: August 1955
Creator: Kalil, Ford

Kinematics of the Relativistic Two-Body Problem

Description: Abstract: "The kinematics of elastic scattering, inelastic scattering, and the two body reaction problem is developed in the relativistic limit and exact expressions obtained for the energies, angles, and solid-angle transformations involved. The results are specialized for zero rest mass of one or more of the particles involved. An outline for the coding of the problem on the I.B.M. Electronic Data Processing Machine, Type 701 is presented."
Date: August 1955
Creator: Blumberg, Leroy & Schlesinger, Stewart I.

Determination of Hydrogen in Lithium Hydride

Description: Abstract: "A method for determining hydrogen in lithium hydride by heating samples with lead at 600 C, was developed. The hydrogen evolved during thermal decomposition of the hydride is purified and oxidized to water with cupric oxide at 400 C. The analysis is completed by collecting and weighing this water. Success in development of the analytical procedure has depended upon a careful design and assembly of equipment for handling samples in a dry, inert atmosphere. For seven pure hydride samples analyzed by the recommended method the estimates of the standard deviation varied between 0.12 and 0.41 percent lithium hydride (or 1.3 and 4.2 parts per thousand) for 8 to 18 determinations on each sample. The procedure is relatively insensitive to variations in certain conditions. For single-piece samples weighing 0.2 to 0.5 gram it was found to be more satisfactory than a method which uses mercury in place of lead for sample decomposition. For powdered lithium hydride samples the lead and mercury methods are equally satisfactory."
Date: May 1954
Creator: Bergstresser, K. S. & Waterbury, Glenn R.

Notes on Evaporation of Target Materials

Description: Abstract: "The general utility of vacuum evaporated films is discussed. The characteristics that makes this technique most useful are the uniformity of the films, the easy control of their thickness over a large range, and the adaptability of the system to different metals and compounds. The design of a vacuum evaporator should provide adequate pumping speed, cooling of components, filament heater supply, and general flexibility and adaptability of the components to different materials. The design of filaments or boats and the evaporation of Al, Ag, Au, Li, Na, UCl4, ThF4, Be, SiO, Nal (Tl), U, and UO2 are considered. Special attention is given to the problem of obtaining uniform layers of UO2 on a large, flat target relatively close to the source."
Date: March 1953
Creator: Northrop, J. A. & Stokes, R. H.

The Decontamination of Uranium from Fission Products by the Use of the Uranyl Oxalate Precipitation Reaction

Description: Abstract: "Decontamination factors of the order of 10-4 were obtained for Beta and Gamma emitters present as fission products when uranium was precipitated from 50 mC activity level solutions as uranyl oxalate under normal uranium yield conditions for three cycles (~60%). Factors of the order of 10-3 were obtained by the use of this reaction with similar solutions under relatively high uranium yield conditions for three cycles (~90%). The uranium peroxide precipitation reaction proved to be of no value on such solutions, yielding decontamination factors of only 17.1 Beta emitters and 1.2 for Gamma emitters for three cycles."
Date: May 10, 1951
Creator: Kelchner, B. L.