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Experimental Techniques, Part 2: Ionization Chambers and Counters

Description: Declassified Manhattan Project document on alpha particle detectors, absolute counters, neutron recoils detectors, reactions detectors, and fission detectors,
Date: 1947
Creator: Rossi, Bruno Benedetto & Staub, Hans Heinrich
Partner: UNT Libraries Government Documents Department

Balanced Ionization Chamber for Differential Measurements of Gamma Rays

Description: "The purpose of the work was to develop a method of measuring very small differences in the half lives of gamma ray emitting radioactive substances. The apparatus was then used to try to detect a difference in the half lives of Be7 metal and BeO. The results of the measurements on the two different chemical forms of beryllium will be given" (p. 1).
Date: 1947
Creator: Wiegand, Clyde
Partner: UNT Libraries Government Documents Department

The Heat of Solution of Uranium Tetrachloride in Aqueous Perchloric Acid Solutions

Description: Abstract: "The heat of solution of UCl4 solid has been measured and found to change appreciably with changing concentration of H+ or ionic strength. The heat of hydrolysis of U+4 to form UOH+3 is probably of the order of +11 kcal per mole" (p. 1).
Date: August 19, 1947
Creator: Fontana, B. J.
Partner: UNT Libraries Government Documents Department

Model Study of Wave and Surge Action, Naval Operating Base, Terminal Island, San Pedro, California

Description: The study reported herein was conducted in 1944 at the Waterways Experiment Station for the Bureau of Yards and Docks, U. S. Navy Department. Its purpose was to determine the best of several plans proposed for protecting the piers and dry docks at the Naval Operating Base, Terminal Island, San Pedro, California, from the effects of wave and surge action.
Date: September 1947
Creator: Waterways Experiment Station (U.S.)
Partner: UNT Libraries Government Documents Department

Uranium Peroxide

Description: It was desired to investigate the precipitation of UO{sub 4} in acid solution, in order to determine the suitability of this reaction for use in the purification of uranium. A series of tests was performed to establish the conditions for precipitation of UO{sub 4}. It was found that uranium could be completely precipitated from pure uranyl sulfate solution at a pH of 2.5 to 3.5, with only silght excess of H{sub 2}O{sub 2}. The presence of sodium sulfate interferred with complete precipitation. It was established that vanadium was preferentially oxidized, when present.
Date: April 14, 1947
Creator: Brimm, E. O., Dr. & Nohr, P.
Partner: UNT Libraries Government Documents Department

Precipitation of Sodium Diuranate from Pitchblende Liquors

Description: In the treatment of carnotite concentrates, sodium diuranate was prepared by acidifying tricarbonate liquors to eliminate carbon dioxide, and then precipitating the sodium salt by the addition of caustic. Direct precipitation of uranium by the addition of caustic to tricarbonate liquors was used when pitchblende ores were processed, because this procedure was more effective in giving a product with a low molybdenum content. Tests of this method in the laboratory and Pilot Plant indicated that low uranium losses (0.2 to 0.3%) would be encountered with typical liquors if 1.7 to 2.0 lbs of caustic were added for every pound of uranosic oxide in solution. Since losses as high as 3% were incurred in plant operations, further work was undertaken, in an effort to reduce the uranium concentration in the waste liquors.
Date: February 4, 1947
Creator: Brimm, E. O., Dr.
Partner: UNT Libraries Government Documents Department

Preparation and use of Ammonium Diuranate in the Ether Extraction Process

Description: In the ether extraction process, as originally developed, purified uranium dioxide was obtained by evaporation and calcination of the uranyl nitrate solution, followed by calcination of the resultant UO{sub 3}. It was suggested that an alternate procedure might be developed, involving the precipitation of uranium from the nitrate solution as ammonium diuranate. This material could then be calcined to uranosic acid, or reduced directly to the dioxide. It had already been established that ammonium diuranate could be precipitated completely from uranyl nitrate solutions. Experiments were carried out to determine whether a basic nitrate, analogous to a known sulfate salt, would be formed in the process. Both direct reduction of the diuranate to UO{sub 2} and calcination to uranosic acid were investigated to determine the physical characteristics and residual nitrogen of the resultant brown oxide.
Date: February 4, 1947
Creator: Brimm, E. O., Dr. & Mohr, P.
Partner: UNT Libraries Government Documents Department

Preparation of 1-C14-Propene-1 and the Mechanism of PermanganateOxidation of Propene

Description: 1-C{sup 14}-propene has been prepared. The migration of the double bond under a variety of experimental conditions in the preparation of propene has been investigated. The mechanism of the permanganate oxidation of the labeled propene has been examined; it has been found to proceed by several paths, the relative importance of which depends upon the experimental conditions, especially the pH.
Date: December 10, 1947
Creator: Fries, B.A. & Calvin, M.
Partner: UNT Libraries Government Documents Department

Diffraction Effects in Neutron Attenuation Measurements

Description: All errors due to diffraction effects in a neutron attenuation experiment are computed. Also a special experiment to measure the forward intensity of diffracted neutrons from lead and copper is described, and the results given. These agree with the theoretical values.
Date: November 1, 1947
Creator: McMillan, E.M. & Sewell, D.C.
Partner: UNT Libraries Government Documents Department

Brookhaven National Laboratory Scientific Progress Report: April 1, 1947

Description: From introduction: The fundamental purpose of the laboratory is to provide research and training facilities in nuclear and related studies which are not possible for the individual University.
Date: April 1, 1947
Creator: Brookhaven National Laboratory
Partner: UNT Libraries Government Documents Department

Distribution of Boron in Processing of Carnotite Concentrate

Description: It was desired to determine the distribution of boron in the various steps of the processing of domestic ore concentrates containing high percentages of boron. The experiments described in this report were directed toward that end. Summary of this report are: (1) a black oxide containing 0.6 ppm of boron was prepared from material containing 350 ppm; (2) less than 0.02% of the boron in the original material appeared in the black oxide; (3) the iron step did not remove appreciable amounts of boron; (4) the bulk of the extracted boron was removed in the soda salt precipitation; and (5) some of the boron was removed in the acid leach and calcination steps.
Date: March 13, 1947
Creator: O'Connors, R. J.
Partner: UNT Libraries Government Documents Department

The Distribution of Impurities in the Ether Extraction Process

Description: When uranium is purified by the ether extraction method, black oxide is dissolved in nitric acid and ether is added; an ether layer containing uranium and an aqueous layer containing uranium and impurities are obtained. The distribution of some impurities between the two phases and the effect of such impurities on the extraction process were studied. the processing required in the preparation of pure uranyl nitrate might be decreased if, instead of uranosic oxide, sodium diuranate was used as a source of uranium. If it is assumed that uranosic oxide contains the same amounts of impurities as sodium diuranate, with the exception of soda, the extraction of soda by the wash of an ether solution of nitrate prepared from diuranate would be the criterion of suitability of sodium diuranate. The distribution and effect of sodium in the extraction process was therefore investigated, and the results are described in this report. For various of the impurities, the distribution in the process and the effect on uranium holdup in the insoluble cake was investigated. Particular attention was given to the behavior of boron, vanadium, chromium, and molybdenum.
Date: January 22, 1947
Creator: Brimm, E. O., Dr. & Mohr, P
Partner: UNT Libraries Government Documents Department

Extraction of Uranium from Iron Box Sludge

Description: It was desired to establish the adaptability of iron box sludge, a residue recovered in the initial concentration of domestic ores, as a raw material from the production of high purity U{sub 3}O{sub 8}. This report summarizes the experimental work on the extraction of uranium from iron box sludge and that on the removal of V{sub 2}O{sub 5} and P{sub 2}O{sub 5} from the solutions.
Date: March 11, 1947
Creator: O'Connors, R. J.
Partner: UNT Libraries Government Documents Department

Excitation Function of the Reaction C12(n,2n)C11 at High Energies

Description: The excitation curve for the reaction C{sup 12}(n,2n)C{sup 11} has been calculated for energies up to 100 Mev. The calculations were done as described in the preceding letter for the similar reaction of C{sup 12} under proton bombardment. The results of the calculations for 50% charge exchange are shown in Figure 1. The calculated cross section for the reaction at 90 Mev is: .011 barns for 100% charge exchange and .013 barns for 50% charge exchange. The experimental value is 0.025 {+-} .004 barns. The ratio of the cross section of the reaction C{sup 12}(pnpn)C{sup 11} to the cross section of the above reaction at 90 Mev is 5.8 for 100% charge exchange and 3.8 for 50% charge exchange. The experimental ratio is 2.7 at 90 Mev. This difference in cross sections between the two reactions is established by two factors. Firstly, there is the part played by charge exchange in the C{sup 12}(pnpn)C{sup 11} reaction which leads to excited N{sup 12} with the subsequent boiling off of a proton, while a similar exchange process cannot take place for the C{sup 12}(n2n)C{sup 11} reaction. Secondly, there is the difference between the contributions of the knock out process as a result of the difference in the n - p and the n - n cross sections, which favors the p + C{sup 12} knock out reaction. It will be noted that the parts of the reactions which go through excited C{sup 12}, while practically equal, are so small that they do not greatly affect either reaction. Although the results of these calculations do not agree too closely with the experimental results, the results are probably as good as are to be expected because of the crudity of the assumed model. The results do, though, seem to give a good qualitative picture ...
Date: November 1, 1947
Creator: Heckrotte, Wolff & Wolff, Peter
Partner: UNT Libraries Government Documents Department

Excitation Function of the Reaction C12(p,pn)C11 at High Energies

Description: Chupp and McMillan have recently measured the excitation curve for the reaction C{sup 12}(pnpn)C{sup 11} at high energies. Using the model of the nucleus described by Serber, the excitation curve of the above reaction has been calculated for energies up to 100 Mev. The excitation of the nucleus is determined on the basis that the incident proton makes individual collisions with the nucleons, the transferred energy exciting the nucleus. n-p collisions are taken to be three times more probable than n-n or p-p collisions. Charge exchange is assumed. The calculations were made for both 50% and 100% charge exchange. The decay of the excited nucleus is treated by the usual evaporation mode.
Date: November 1, 1947
Creator: Heckrotte, W. & Wolff, Peter
Partner: UNT Libraries Government Documents Department

Half-Scale Model Tests on the Three Quarter Wave R.F. System for the 184-inch Frequency Modulated Cyclotron

Description: Performance curves and test results on a half scale model of the radio frequency system designed to accelerate protons in the Berkeley 184-inch cyclotron are presented. This report is a sequel to K. R. Mackenzie's report on the three quarter wave radio frequency system for frequency modulated cyclotrons.
Date: December 30, 1947
Creator: Anderson, Robert L.
Partner: UNT Libraries Government Documents Department

Electronic Circuits Lectures

Description: The two-electrode vacuum tube, or diode, consists of an electron-emitting cathode surrounded by a positive anode (plate). A plot of plate current (i{sub b}) vs plate voltage (e{sub b}) is shown. At low anode voltages, the anode current is limited by the repelling effect that the negative electrons already in the space have on the electrons just being emitted (space-charge effect). When a full space charge is present, the plate current depends upon the plate voltage according to Childs law: i{sub b} {approx} e{sub b}{sup 3/2}. Increasing the plate voltage eventually results in an electron flow equal to total cathode emission, after which further increases in anode voltage will produce practically no additional current (voltage saturation). However, for high field stresses, additional electrons are pulled out of the cathode (field emission), increasing the current even further.
Date: December 1, 1947
Creator: Mozley, Robert
Partner: UNT Libraries Government Documents Department

Diffraction Effects in Neutron Attenuation Measurements

Description: All errors due to diffraction effects in a neutron attenuation experiment are computed. Also a special experiment to measure the forward intensity of diffracted neutrons from lead and copper is described, and the results given. These agree with the theoretical values.
Date: November 1, 1947
Creator: Sewell, D.C. & McMillan, E.M.
Partner: UNT Libraries Government Documents Department

Progress Report for October 1947, Physics Section

Description: This summary discusses the following topics: (1) 184-inch cyclotron program; (2) a 60-inch cyclotron program; (3) synchrotron program; (4) Linear accelerator program; (5) Experimental physics, experiments with the 184-inch cyclotron, fast neutron scattering, and neutron-proton scattering; (6) Theoretical physics; and (7) isotope research program.
Date: October 1, 1947
Creator: Brobeck, W.M.; Hamilton, J.G.; Martin, M.; Alvarez, L.W.; Thornton, R.L.; Serber, R. et al.
Partner: UNT Libraries Government Documents Department

Proton Angular Distribution for 90 Mev Neutron-proton Scattering

Description: The angular distribution of the recoil protons in neutron-proton scattering at 90 Mev has been measured for angles between 5{sup o} and 65{sup o} from the direction of the neutron beam. The neutrons were produced by stripping 190 Mev deuterons in a 1/2 inch Be target in the 184-inch F.M. cyclotron. R. Serber has calculated the neutron energy distribution; it has a peak at 90 Mev and a half width of 27 Mev. This distributiQn has been checked experimentally for the neutrons by Wilson Powell and by W.Chupp, E.Gardner, and T.B.Taylor for the protons also produced by stripping. The neutrons were collimated by a two-inch hole through 8 feet of concrete. Thin paraffin scatters of known hydrogen and carbon content were used; the number of protons arising from neutron-carbon and neutron-air reactions was determined by using pure carbon scatters and by making blank runs. The scatters were placed in the beam outside of the concrete shielding at a point approximately 52 feet from the cyclotron target. The scattered protons were detected by a telescope of four proportional counters used in coincidence, and set at a constant distance from the scatterer but at a varying angle from the neutron beam. A copper absorber was placed between the scatterer and the counters. The thickness of the absorber was adjusted for each angle so that only protons scattered by incident neutrons of energy greater than 66 Mev could be counted. It was found that the results did not depend on whether the absorber was placed in front of all four counters, or between the first two. The beam was monitored by placing a second one inch piece of paraffin in the neutron beam and measuring the protons scattered from it by means of two additional proportional counters. Fig. 1 is a plot of ...
Date: November 3, 1947
Creator: Hadley, James; Leith, Cecil E. & York, Herbert F.
Partner: UNT Libraries Government Documents Department

Progress Report for 1947

Description: The year 1947 has witnessed the dawn of a new era of atomic science, a flowering of fundamental knowledge of the nature of matter which appears to be unsurpassed even by that period of the 1930's which led to the age of plutonium. A great new cyclotron, an atom-smasher ten times more powerful than the one which brought plutonium into the world, has carried mankind over a new horizon of sub-atomic space. It has brought scientists at last to grips with the infinitely small and rapid forces, until now beyond reach, which operate within the incredibly tiny distances of nuclear space. On the new energy frontier created by the giant machine, now laws govern nuclear reactions. methods are at hand, heretofore unavailable, which permit the measurement and determination of the nature of sub-atomic forces. Under ultra-high energy bombardment, the nucleus presents a different appearance from the nucleus of Bohr and Rutherford, the nucleus of atomic energy fission. The new exploration of the atom has been sponsored by the Atomic Energy Commission with the giant, new 4000-ton cyclotron in the Radiation Laboratory of the University of California. This is the thirdmajor machine built by the Director of the Laboratory and inventor of the cyclotron, Professor Ernest O. Lawrence. Whether the new knowledge will be of immediate practical consequence cannot now be predicted. Nor could Professor Lawrence predict, when in 1934 he established a new atomic energy range for that day with his first cyclotron, that the fundamental knowledge he pursued would be climaxed with the discovery of plutonium. What can be predicted is this: without the new basic knowledge, practical atomic developments of the future would be limited to the applicability of the fundamental information which made possible the initial release of atomic energy. In short, the nation's atomic potential has ...
Date: November 1, 1947
Creator: Authors, Various
Partner: UNT Libraries Government Documents Department