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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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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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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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Thermal Stresses Arising from Defective Strip in Bond

Description: Stresses set up by an insulating strip in the bond are estimated and found to be small compared to those normally present without the defect.
Date: May 18, 1944
Creator: Young, G.
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
open access

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
Partner: UNT Libraries Government Documents Department
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