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The Slow Neutron Transmission of Be Metal as Measured by a Neutron Beam Spectrometer in the Energy Region 0.004 eV to 50 eV

Description: Abstract. Slow neutron transmission measurements as a function of the time of flight of the incident neutron have been made for three different thicknesses of Beryllium. The energy region from 0.004 eV to 50 eV was investigated using the Columbia neutron beam spectrometer system. Particular emphasis was placed on the very low energy region (from 0.004 eV tp 0/2 eV or from 0.6 to 5 [length]) where pronounced crystal interference effects were observed. The effective slow neutron cross section (in… more
Date: October 11, 1944
Creator: Rainwater, Leo James, 1917- & Havens, W. W. (William Westerfield), Jr., 1920-2004
Item Type: Refine your search to only Report
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A Method for Neutron Energy Measurement

Description: This technical report discusses a method proposed to measure neutron energies by accurately determining the momenta of recoil protons in a magnetic spectrometer specially designed for this purpose. The main consideration in the design of the spectrometer is the shielding of the detector from the high radiation background associated with intense neutron beams.
Date: October 18, 1944
Creator: Nedzel, V. Alexander
Item Type: Refine your search to only Report
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A Sensitive Particle Ionization Chamber for Neutron Detection

Description: Abstract. A particle ionization chamber of sensitivity sufficient to detect a source of one neutron per second has been used to measure the neutron yield from a thick target of sulfur upon bombardment with polonium alpha particles. The high-geometry boron trifluoride chamber used had an efficiency of 1.9 percent for fission neutrons. The neutron yield from a thick target of sulfur was measured by this instrument and found to be .0035 +- .0013 neutrons per million incident polonium alpha particl… more
Date: November 21, 1944
Creator: Sturm, William J. & Dabbs, John
Item Type: Refine your search to only Report
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A Final Report on the Experiment : the Penetration of Graphite of Different Purities by Lead Bismuth Eutectic

Description: Bi-Pb eutectic and pure Bi penetration of graphites of various densities under 300 degrees C and pressures up to 20 psi was found be of the order of magnitude of 1.0 g/cm(2) and was uniform throughout the graphite. Bi was absorbed less than the eutectic but the oxidation rate of Bi would be prohibitive. There was heavy nitriding in N atmospheres with the Bi and the eutectic.
Date: September 25, 1944
Creator: Stroud, William G.
Item Type: Refine your search to only Report
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Further End Cap Temperature Calculations

Description: Abstract. Recently (CP-1989) it has been shown that the neutron density, and thus the heat production, at the end of a slug with an A1 cap may be appreciably higher than that at the middle of the slag. A re-examination of earlier temperature calculations is made in light of this effect.
Date: August 16, 1944
Creator: Karush, William; Monk, A. T. & Wilkins, J. Ernest, Jr., 1923-2011
Item Type: Refine your search to only Report
open access

Warping Instability in Long Rods

Description: Abstract. If a pile rod gets bowed within its cooling tube it becomes warmer on the side which approaches the tube wall, and thermal expansion tends to warp it in the same direction as the original displacement. This was discussed roughly in N-601, and it was there concluded that the mechanism was not important for an isolated short slug. In connection with current development of continuous jacket (cartridge) assemblies, it seems desirable to look at this question again. In this case it is poss… more
Date: August 17, 1944
Creator: Young, Gale Jay
Item Type: Refine your search to only Report
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Progress Report : Low Geometry Alpha Particle Ionization Chambers

Description: ABSTRACT. When solutions of high specific alpha activity are to be assayed for product, it is often difficult to obtain reproducible results by diluting the solution sufficiently to remove a small volume from which a sample can be prepared and counted at 52% geometry. In order to assay such a solution, most reproducible results have been obtained with minimum effort in sample preparation by making use of low geometry chambers. Two types of low geometry chambers are described: 1) The air-screen … more
Date: November 8, 1944
Creator: Borokowski, C. J.; East, J. K. & Flatau, C.
Item Type: Refine your search to only Report
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The Distribution of Thermal Neutrons in a Slug with Thick End Caps

Description: The distribution of thermal neutrons in a W slug having a one centimeter aluminum end cap has been calculated on the basis of simple diffusion theory. It is found that the average neutron density, and therefore the power output, at the end of the slug is about 34% higher than the density far from the end cap. This result agrees well with the recent Argonne pile experiments (CP-1729).
Date: August 3, 1944
Creator: Wilkins, J. Ernest, Jr., 1923-2011
Item Type: Refine your search to only Report
open access

Temperature and Heat Flow in a Graphite Electrode

Description: In making various experimental heat studies a power producing metal slug is simulated by a slug with a graphite rod electrode of 3/8" diameter inserted lengthwise through it. There is a helium filled annular space between the graphite and the inner surface of the slug cylinder. Radiant heat passes from the electrode to the metal; with proper adjustment of the electrode current the slug in the steady state will therefor "produce" the same amount of energy from its exterior surface as it would un… more
Date: August 3, 1944
Creator: Schlegel, R.
Item Type: Refine your search to only Report
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Sealing of Holes in Aluminum Sheet by Oxidation

Description: Aluminum oxide occupies a larger volume than the aluminum it contains would fill as metal, consequently, the assumption has been made that holes in metallic aluminum would close by a sufficient amount of oxidation. Therefore, we were asked to investigate the rate of plug formation under conditions to be expected in the pile. For the latter we were requested to approach the pile conditions as nearly as we could by employing the Chicago cyclotron. It seems to us that the problem divides itself in… more
Date: July 15, 1944
Creator: Anderson, S. & Goldowski, N.
Item Type: Refine your search to only Report
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Extrusion of Compound Tubes of Aluminum and B4C

Description: Various experimenters have shown (H.H. Gersman U.S. Patent 2,335,590, Nov. 30, 1943; Aluminum Co. of America, various technical papers; also CT-482) that when a billet is extruded by proper technique into a rod (or tube by a floating mandril) that flow of material is streamline and and the extruded article is essentially a space replica of the billet, with linearly distorted coordinates. Advantage is taken of this fact in the manufacture of alclad tubing in which a billet containing an inner co… more
Date: July 1, 1944
Creator: Creutz, E. C.
Item Type: Refine your search to only Report
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The Effect of the Maxwell Distribution of Velocities on the Neutron Density and Diffusion Length in a Metal Sphere

Description: The change in the simple [formula] distribution of neutrons in a spherical lump of uranium caused by the distribution in velocities of thermal neutrons is calculated. If the calculated curve is fitted as well as possible by a simple [formula] curve, it is shown that the value of [formula] obtained in this way is a function of [formula], the radius of the sphere. For small radii the [formula] obtained in this manner will be as much as 25% greater than the [formula] corresponding to average veloc… more
Date: June 27, 1944
Creator: Plass, Gilbert N.
Item Type: Refine your search to only Report
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Representation of Slowing Down Functions in Water by Synthetic Kernels

Description: Fermi, Anderson, and Nagle's experimental distribution of Indium resonance neutrons around a point source of fission neutrons in water has been fitted by analytic expressions which are source functions in the two-group, three-group, Fermi and Christy-Wheeler pile theory. The Christy-Wheeler function (exponential followed by a Gaussian) is the best fit; the two-group function (exponential) is slightly better than the Fermi Gaussian.
Date: June 1, 1944
Creator: Cahn, Albert, Jr.
Item Type: Refine your search to only Report
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A Case of Rod Warping

Description: Warping of a rod by a variation in heat transfer coefficient around the periphery is considered. Estimates for some simple cases are given, and a more precise numerical calculation is carried out in ne instance.
Date: May 27, 1944
Creator: Murray, F. & Young, Gale Jay
Item Type: Refine your search to only Report
open access

Experiments on the Evaporation of Boron in Vacuo : Progress Report No. 1 on a Phase of Problem No. 132 - ML - 56-3; File Serial 13

Description: It was desired to determine a method of evaporating boron to form a rather pure uniform tenacious coat of specified thickness. These coats are needed as monitoring films for neutron intensities, particularly in steel ionization cylinders. The most satisfactory method of evaporating boron employed a graphite filament. A mixture of amorphous boron and Carbenoid A was painted onto the filament which was then heated by electrical resistance method to 2300 degree C at which temperature the boron eva… more
Date: March 31, 1944
Creator: Friel, D. D.
Item Type: Refine your search to only Report
open access

The Diffusion Length of Thermal Neutrons in Uranium

Description: Measurements made in a uranium cylinder result in a mean value of 1.55 cm. for the diffusion length L for distances of 1 to 4 cm. from the base of the cylinder. Calculations give a value which agrees with the experimental result and show further that L increases from 1.40 to 1.63 cm. as the neutrons diffuse a distance of 5 cm. into the uranium.
Date: May 27, 1944
Creator: Hughes, Donald James, 1915-1960 & Bragdon, E. W.
Item Type: Refine your search to only Report
open access

Resonance Absorption of Uranium in Mixtures

Description: A good determination of the resonance absorption of uranium when admixed with various substances is necessary so that calculations can be made on the efficiency of homogeneous piles. The original experiments along these lines were undertaken by Creutz, Jupnik, and Snyder (C-116) and consisted of experiments on the resonance capture in pure U, UO2, U3O8, and one experiment on capture in a mixture of U3O8 and graphite. These experiments were done at the cyclotron in Princeton and consisted of det… more
Date: March 31, 1944
Creator: Mitchell, Allan C. G. (Allan Charles Gray), 1902-; Brown, Leon J.; Pruett, John R. & Nering, Evar D.
Item Type: Refine your search to only Report
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