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The Temperature Coefficient of the Diffusion Length for Thermal Neutrons in Water

Description: Abstract. The diffusion length of thermal neutrons in water as a function of the water temperature has been measured. The results are expressed as a linear relation: L = 2.644 + 0.0061T where L is the diffusion length in centimeters and T is the temperature in degrees centigrade.
Date: October 28, 1944
Creator: Wilson, V. C.; Bragdon, E. W. & Kanner, H.
Partner: UNT Libraries Government Documents Department
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Slug Temperatures in an Off-Center Annulus

Description: Abstract. Temperatures are measured at two points in an internally heated jacketed slug which is cooled by water flowing in an off-center annulus around the slug. The variations of these temperatures with water velocity, water temperature, power, and the amount the annulus is off center are measured. The temperature near the slug surface which approaches and comes in contact with the water jacket does not increase as much as anticipated. The temperature near the slug surface on the side which i… more
Date: October 10, 1944
Creator: Kratz, H. R.; Peterson, R. & Schlegel, Richard, 1913-
Partner: UNT Libraries Government Documents Department
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Slug Jacket Temperatures

Description: Abstract. A method for calculating jacket temperatures in a region of varying heat transfer coefficients is given Some applications are made for temperatures above a supporting rib.
Date: November 8, 1944
Creator: Schlegel, Richard, 1913-
Partner: UNT Libraries Government Documents Department
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The Thermal Conductivity of Some Project Materials

Description: Abstract. An apparatus for measuring the thermal conductivities materials which are moderately good conductors of heat is described. Results obtained with a sample of pure Th are given on p. 10, 12, and 13.
Date: December 7, 1944
Creator: Raeth, Charles H.
Partner: UNT Libraries Government Documents Department
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Neutron Distribution Around a black Sphere with a Gap

Description: Abstract. Successive approximations ae obtained from transport theory for the neutron distribution around a black sphere surrounded by a spherical gap and a non-absorbing medium extending to infinity. Six cases are calculated numerically to show the difference between this treatment and simple diffusion theory. The extrapolation distance and a quantity that is essentially the thermal utilization are calculated in different approximations. It is found that the neutron density in the gap, instead… more
Date: December 5, 1944
Creator: Plass, G. N.
Partner: UNT Libraries Government Documents Department
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On the Statistics of Rod Warping

Description: Abstract. The probability of exceeding assigned values of displacements or forces in simple rod models assembled from slugs picked at random is discussed, and some estimate for the statistical gain resulting from use of shorter slugs is obtained. The probability that a rod with self-warping will touch the top of the tube appears great enough to justify a recommendation of the use of top ribs.
Date: December 28, 1944
Creator: Martin, A. V. & Young, G.
Partner: UNT Libraries Government Documents Department
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The Digging-in of a Warped Rod Into a Rib

Description: Abstract. Some rather idealized considerations are given regarding the depth a warped rod presses into the ribs at the places of contact. It appears that this distance may, under some conditions, be of the order of 70 times greater than for a straight rod resting uniformly on the ribs.
Date: January 22, 1945
Creator: Martin, A. V.
Partner: UNT Libraries Government Documents Department
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Final Report on Swell Detection by Pusher Method

Description: Experiments wee performed to evaluate the feasibility of detecting swelled slug elements in Hanford reactors by measuring the force necessary to push the slug column in its tube. These experiments are described. The results indicate the method presents no unsolvable problems.
Date: November 11, 1944
Creator: Shank, W. Bradford & Frankel, W.
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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The Hall Effect in Neutron Irradiated and Annealed Graphite

Description: Abstract. Irradiated Whiting graphite possesses a small negative or a positive Hall constant, depending upon the dosage. Annealing at 500 degrees C for 1 hour in helium results in a Hall constant which is large in magnitude and negative in sign. The properties of the annealed graphite are presumably close to those of the original unirradiated material. Unirradiated AGOT-K graphite has a large, negative Hall constant. A mechanism is suggested which accounts for the change in sign of the Hall con… more
Date: April 18, 1945
Creator: Maurer, Robert J. & Ruder, Richard C.
Partner: UNT Libraries Government Documents Department
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A Note on the Kinetics of Homogeneous Piles

Description: Abstract. In investigating stability of a homogeneous pile it has been customary to assume that the production of bubbles follows the production of power instantaneously. Here we investigate the implications of introduction of an intermediate dissolved gas stage under two hypotheses on the formation of bubbles from this dissolved gas. It is seen that this additional stage tends to make the pile unstable.
Date: June 26, 1945
Creator: Wilkins, J. Ernest, Jr., 1923-2011
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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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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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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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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Temperature Coefficient of the Reproduction Factor for Different Lattice Arrangements

Description: The temperature coefficient is calculated for various lattice arrangements, taking into account the variation of [formula], suggested by Fermi. Four contributions are included: leakage, levelling of the dip in thermal neutron density in the lump, resonance absorption, and hardening of the neutrons as they penetrate a metal lump. The departure of neutron temperature from lattice temperature decreases the total coefficient. Values are given for 3 typical piles; in general, the larger the uranium … more
Date: February 10, 1943
Creator: Morrison, P.
Partner: UNT Libraries Government Documents Department
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Effect of Temperature on the Resonance Absorption of Neutrons by Uranium

Description: The resonance absorption of uranium for neutrons has been investigated between 20 degree C and 1000 degree C. Experiments were caried out on both UO2, density 4.63, and metal. The resonance activity was measured with respect to that of an iodine monitor at several different temperatures and the ratio of activity at temperature T to that at 20 degree C was determined. The increase in activity is 0.9 per cent per 100 degree C for the oxide and 1.1 percent per 100 degree C for the metal. The perio… more
Date: April 22, 1943
Creator: Mitchell, Allan C. G. (Allan Charles Gray), 1902-; Slotin, Louis; Marshall, John; Nedzel, V. A.; Brown, L. J. & Pruett, John R.
Partner: UNT Libraries Government Documents Department
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On the Multiplication Constant of Homogeneous Mixtures of U with Various Moderators

Description: The following represents a summary of calculations on the multiplication constant of homogeneous mixtures of uranium and different moderators. These calculations were made possible by Fermi's determination of the age of neutrons and by the extrapolation to higher scattering cross-sections of the resonance absorption of uranium as measured by C. Creutz. According to Fermi, the former quantity is 120 sq. cm. The latter is given in the two attached graphs. The first (Fig.1) of these goes as high a… more
Date: May 16, 1943
Creator: Wigner, Eugene Paul, 1902-1995 & Stephenson, J.
Partner: UNT Libraries Government Documents Department
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Some Cases of Pile Activity Flattening

Description: Radial flattening of activity in the cores of spherical and cylindrical piles is discussed in connection with pile control and power improvement. Partial flattening as a result of k loss from temperature rise is also considered.
Date: October 10, 1943
Creator: Morehouse, N. & Young, G.
Partner: UNT Libraries Government Documents Department
open access

Temperature Effect in Homogeneous Pile

Description: Some idealized considerations of the temperature field in the homogeneous pile are given. It is crudely estimated that the effective mean temperature rise of the pile to be used in calculating the k loss is something like 3/4 the rise in temperature of the slurry in passing through the pile.
Date: December 9, 1943
Creator: Young, Gale Jay
Partner: UNT Libraries Government Documents Department
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Recalculation of the Critical Size and Multiplication Constant of a Homogeneous UO2 - D2O Mixtures

Description: The multiplication constant and optimal concentration of a slurry pile is recalculated on the basis of Mitchell's recent experiments on resonance absorption. The smallest chain reacting unit contains 45 to 55 m3 of D2O.
Date: February 11, 1944
Creator: Wigner, Eugene Paul, 1902-1995; Weinberg, Alvin Martin, 1915-2006 & Stephenson, J.
Partner: UNT Libraries Government Documents Department
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