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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.
Partner: UNT Libraries Government Documents Department
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Poisoning and Production in a Power Plant

Description: The yield of 49, the efficiency of production of 49, and poisoning in a power plant are discussed. Only the crudest of estimates of the poisoning are possible: these indicated that production will probably not be hampered by poisoning. In this case the yield of 49 could be as high as 3 kg/ton but only about 2 kg/ton is compatible with a fairly high efficiency. In the case that production is stopped by poisoning, smaller yields, proportional to the tolerable loss in k, are obtained. In this case… more
Date: December 15, 1942
Creator: Ashkin, J.; Christy, Robert F., 1916-2012 & Feld, Bernard T. (Bernard Taub), 1919-1993
Partner: UNT Libraries Government Documents Department
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The Effect of Thermal Cycling on the Thermal Transfer from a Sand Blasted Slug to an Unbonded Jacket

Description: Abstract. Measurements were made to determine the effect of thermal cycling on heat transfer from slug to jack using a slug with a sand blasted surface. The value of the transfer coefficient h decreased from initial values ranging from 10 to [formula], to values and [formula] after 1700 cycles, and to a range of 0.15 to 0.45 [formula] after 3200 cycles. Comparisons are made with the results found for slugs with different surfaces.
Date: April 2, 1945
Creator: Bentley, Robert R.
Partner: UNT Libraries Government Documents Department
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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.
Partner: UNT Libraries Government Documents Department
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Interaction of Be with Fission Neutrons

Description: To determine whether or not the (n,2n) reaction in Be would produce a net increase in fission neutrons in a power plant, the distribution of In resonance neutrons slowed down from fission energies in a graphite block was measured with and without a 2" of Be in front of a U3O8 slab undergoing fission. The thermal neutrons producing the fissions were obtained by slowing down neutrons from a cyclotron source. The observed distribution without Be was well represented by a Gaussian source range 36 c… more
Date: April 29, 1942
Creator: Borst, L.; Allison, S. K.; Wheeler, John Archibald, 1911-2008 & Weinberg, Alvin Martin, 1915-2006
Partner: UNT Libraries Government Documents Department
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Eta Temperature Effect

Description: The temperature coefficient of eta has been measured with the thermal column of the Argonne pile using uranium foils of different isotopic ratios. The temperature change was effected by filtering neutrons through silver. The measured fractional change per degree centigrade is [formula].
Date: February 25, 1944
Creator: Bragdon, E. W.; Hughes, D. & Marshall, John
Partner: UNT Libraries Government Documents Department
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Effect of Routing Upon Temperature of Cooling Stream

Description: With discussion under way concerning power production by chain reacting piles, it becomes pertinent to consider the ration of the temperature of the hottest spot in the pile to the average exit temperature of the cooling stream. This is important because the temperature of the hottest spot in the pile is one of the limiting factors in determining the maximum power at which a pile can be operated. However, the higher the temperature of the emerging cooling stream, the more efficient can be the t… more
Date: February 14, 1946
Creator: Cahn, Albert S., Jr.
Partner: UNT Libraries Government Documents Department
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Theory of Oscillating Absorber in a Chain Reacting Pile

Description: Abstract. the fluctuation in pile intensity caused by an oscillating point absorber is calculation. It is found that the nature of the response depends on the frequency of the impressed oscillation. If the frequency is high compared to the decay rate of the high harmonics, the response consists of a wave which is propagated away from the oscillator. If the frequency is low, the propagated wave character of the response disappears and the intensity of the whole pile tends to oscillate with the s… more
Date: April 6, 1945
Creator: Cahn, Albert S., Jr.; Monk, A. T. & Weinberg, Alvin Martin, 1915-2006
Partner: UNT Libraries Government Documents Department
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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.
Partner: UNT Libraries Government Documents Department
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The Effect of Fast Fission on k

Description: The importance of fast neutron fission (i.e., fission caused by neutrons before being slowed down) was recognized by Szilard, and calculations similar to the present one have already been carried out by him, Feld, Ashkin, Wheeler, Wigner and others. The purpose of the present paper is to give a general formula for the contribution of fast fission to the multiplication constant, which will include all the cases already considered and will be applicable to more complicated geometries than those c… more
Date: May 4, 1943
Creator: Castle, H.; Ibser, H.; Sacher, G. & Weinberg, Alvin Martin, 1915-2006
Partner: UNT Libraries Government Documents Department
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Chain Reaction of Pure Fissionable Materials in Solution

Description: The critical mass of 94-239 and the corresponding critical dimensions of homogeneous mixtures of 94-239 with various moderating media been calculated as a function of the concentration of 94. A simple transformation makes the figures applicated to92-235. the results are in essential agreement with the preliminary estimated made independently by Oppenheimer and Serber. The problem of the stability of a chain reaction in solution and questions of protection are discussed.
Date: January 1, 1943
Creator: Christy, Robert F., 1916-2012 & Wheeler, John Archibald, 1911-2008
Partner: UNT Libraries Government Documents Department
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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.
Partner: UNT Libraries Government Documents Department
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Determination on Neutron Density With Bismuth Foils : Final Report - Problem Assignment 131 - X21P

Description: It is usual to determine the density of neutrons by using foils of metals which become radioactive as a result of bombardment in the region under investigation. From the rate of disintegration of the newly formed radioactive element the number of neutrons absorbed can be calculated. By use of the capture cross section of the element of which the foil is composed the density of the neutrons can then be computed. By counting the alpha particles from a bismuth foil of known weight after exposure t… more
Date: May 30, 1944
Creator: Curtiss, Leon Francis, 1895-
Partner: UNT Libraries Government Documents Department
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The Resonance Absorption Spectrum of Uranium

Description: A model for the capture spectrum of uranium is introduced in which levels occur at 7, 30, 30+D, 30+2D, ..., ev. Gamma ray and neutron widths are derived from the experimental data for values of D between 10 and 25 ev. The constants of the 7 volt level prove to be independent of D. Extrapolation, using the one level formula, gives a capture cross section at (1/40) ev of 4.9 x 10(24) cm2; this number is, however, quite sensitive to the value taken for the resonance activation. Both neutron and ga… more
Date: November 24, 1943
Creator: Dancoff, Sidney M., 1913-1951
Partner: UNT Libraries Government Documents Department
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Resonance Absorption in Lumps and Mixtures

Description: The resonance absorption of a lump is described in terms of three components. Calculations of resonance absorption are carried out using the model for the resonance spectrum of uranium recently derived; calculations are also made with variations of this model which involve local fluctuations in level strengths. For metal and oxide lumps the agreement with observation is satisfactory. For dilute mixtures, whose resonance activation was measured by Mitchell, computed values fall 20% to 30% above … more
Date: April 17, 1944
Creator: Dancoff, Sidney M., 1913-1951 & Gingburg, M.
Partner: UNT Libraries Government Documents Department
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Metallurgical Laboratory, Nuclear Physics Division, Report for the Month Ending May 25, 1944

Description: Technical report with short reports from the (1) Experimental Nuclear Physics Group; (2) Theoretical Physics Group ; (3) Lattice Design Group; (4) Pile Design Group; (5) Exponential Experimental Group; (6) Radiation Group; and (7) Shielding Group.
Date: June 14, 1944
Creator: Fermi, Enrico, 1901-1954
Partner: UNT Libraries Government Documents Department
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The Contamination of Cooling Water by a P-9 Plant

Description: The following sources of contamination in cooling water of the P-9 plant are considered: (1) Fission recoils, (2) Corrosion of metal, (3) Recoil from aluminum, (4) Induced activity in the water. It is found that for a P-9 plant of 3.5 x 10(4) KW contamination of the river at "X" should not exceed the .1 r criterion unless coating failure occurs. Tables of the amount of coating failure permissible are given as a function of holdup time.
Date: June 1, 1943
Creator: Friedman, Francis L. (Francis Lee), 1918-
Partner: UNT Libraries Government Documents Department
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On the Boundary Condition Between Two Multiplying Media

Description: The transition region between two parts of a pile which have different compositions is investigated. In the case where the moderator is the same in both parts of the pile, it is found that the diffusion constant times thermal neutron density plus diffusion constant times fast neutron density satisfied the use pile equations everywhere, right to the boundary. More complicated formulae apply in a more general case.
Date: April 19, 1944
Creator: Friedman, Francis L. (Francis Lee), 1918- & Wigner, Eugene Paul, 1902-1995
Partner: UNT Libraries Government Documents Department
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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.
Partner: UNT Libraries Government Documents Department
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The Stopping Power of Metals

Description: Summary. The effect of the conduction electrons on the stopping power of metals has been considered from two essentially different points of view. No numerical calculations have been carried out, because we have found no completely satisfactory was of computing Z'e, the effective charge on the moving ion. A rather crude estimate made on the basis of the Thomas-Fermi atomic model indicates that Z'2/E is roughly constant. Using this relation one finds that the stopping power of the conduction ele… more
Date: July 2, 1945
Creator: Goldberger, Marvin L.
Partner: UNT Libraries Government Documents Department
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The Laplacian for a Beryllium Metal Lattice of Volume Ratio 17.2

Description: Abstract. the Laplacian of a beryllium metal lattice with 3.3 kg of uranium metal per cell and a volume ratio of 17.2 was measured in the removable region of the CP-2 machine. the sandwich effect with different moderators made interpretation of the observations very uncertain. The best result found was Be = 407 x 10(-6) cm(-2).
Date: January 16, 1946
Creator: Goldberger, Marvin L.; Wattenberg, Albert, 1917- & Zinn, Walter H. (Walter Henry), 1906-2000
Partner: UNT Libraries Government Documents Department
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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.
Partner: UNT Libraries Government Documents Department
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Low-Density UO2 Pile

Description: The multiplication factor and minimum pile size for a multiplying pile using UO2 powder of density 1 have been computed. It appears that a k of 1.0177 is possible for a volume ration of V/V001=3.33.
Date: February 24, 1943
Creator: Ibser, H. W.
Partner: UNT Libraries Government Documents Department
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